Comet C/2019 Y4 (ATLAS) has been fainter during the last few nights. It’s possible it’s disintegrating (as comets sometimes do), although it’s still possible ATLAS will survive. Details here.Sharing is caring!
Images of Comet ATLAS – taken on April 5, 2020 – show an elongation of the comet’s nucleus. The elongation is aligned with the axis of the comet’s tail. Astronomers have seen before that comets exhibit this sort of elongation shortly before disintegrating. Is that what’s happening? Image via astronomers Quanzhi Ye (University of Maryland) and Qicheng Zhang (Caltech)/ Ningbo Education Xinjiang Telescope.
Updated April 6, 2020.
Recent observations of Comet C/2019 Y4 (ATLAS) show that it’s fading in brightness. According to observers’ reports, after gradually brightening to magnitude 8 as it crossed Mars’ orbit, the comet has appeared fainter during the last few nights. It has sunk to a magnitude of around 8.8 to 9.2 (the bigger the number, the fainter the sky object). Is Comet ATLAS disintegrating? Are our hopes for a bright comet – or even one visible to the eye – dashed? That’s a possibility … but not a certainty.
We report the possible disintegration of comet C/2019 Y4 (ATLAS), revealed by the public monitoring program carried out by the 0.6-m Ningbo Education Xinjiang Telescope (NEXT). Images taken on UT 2020 April 5.6-5.9 showed an elongated pseudo-nucleus measuring about 3 arcsec in length and aligned with the axis of the tail, a morphology consistent with a sudden decline or cessation of dust production, as would be expected from a major disruption of the [comet’s] nucleus.
Does this mean the end of Comet C/2019 Y4 (ATLAS)? Not necessarily. Time and time again, comets have shown themselves to be erratic and unpredictable. In case Comet ATLAS does remain visible – and in one piece – EarthSky shares some charts below to help you find the celestial visitor.
Original article is below. Be aware that, if the comet has faded, all bets are off for brightness predictions.
A recently discovered comet is getting the attention of astronomers and sky enthusiasts as it’s become brighter than expected in the last few days. Astronomers using the ATLAS (Asteroid Terrestrial-impact Last Alert System) in Hawaii discovered Comet C/2019 Y4 (ATLAS) on December 28, 2019. As of mid-late March, it shines at about the brightness of an 8th-magnitude star – not visible to the eye yet – but within reach of medium-sized telescopes in dark skies. The comet is currently crossing Mars’ orbit and is approaching the inner solar system. As it gets closer to us, it’ll get brighter still. You’ll find charts for observers at the bottom of this post.
Comet ATLAS should become bright enough to be easily visible in binoculars, and perhaps bright enough to be seen with the unaided eye from dark sky locations.
Just know that comets are notoriously erratic and inherently unpredictable! We will have to wait to see how Comet ATLAS performs.
Recently BBC News reported that some British police departments have decided to add extra officers on nights with a full moon.
The concern isn’t over werewolves or vampires—no need to issue silver bullets or wooden stakes—but more human threats such as petty thieves and violent criminals.
For years, some who work in police and emergency services (such as doctors and nurses) have anecdotally claimed that full moon nights are busier, crazier, and more dangerous than nights when the moon is dim. This perception may be rooted more in psychology than reality.
Belief in the moon’s influence is an ancient one, and common in many cultures including our own. If police and doctors are expecting that full moon nights will be more hectic, they may interpret an ordinary night’s traumas and crises as more extreme than usual. Our expectations influence our perceptions, and we look for evidence that confirms our beliefs. (The same thing happens on “bad days” when everything seems to go wrong, but only a few key things actually do.)
Yet carefully controlled studies have not found good evidence supporting this idea.
For example, researchers Ivan Kelly, James Rotton, and Roger Culver, in their study “The Moon was Full and Nothing Happened” (published in the book “The Hundredth Monkey and Other Paradigms of the Paranormal,” 1991) examined more than 100 studies of alleged lunar effects and found no significant correlation between phases of the moon and disasters, homicide rates, etc. Furthermore, there is no known mechanism by which the moon would somehow influence a person’s mind to make him more dangerous—except of course for his own expectations.
Still, though the evidence for any direct influence of a full moon is negligible and contradictory, there is some evidence for a less direct (yet more obvious) connection.
There is a good reason why there may be more crime on the nights of a full moon; it has to do with statistics, not lunacy. People are more active during full moons than moonless nights. An especially beautiful full moon may draw families out into the night to appreciate it, and lovers to local necking spots. Muggers and other criminals who ply their trade at night also use the moon’s illumination to carry out their dirty deeds.
If there is even slightly more activity—any activity—on a full moon night, then that may translate into a slight but real increase in crime, accidents, and injuries. No werewolves needed.
Estimates say that a vehicle-sized asteroid explodes in our atmosphere about once per year, often too high to make a noticeable impact.
But in 2013, a small meteor exploded just 20 miles above Chelyabinsk, Russia that sent over 1,200 people to the hospital. Today, a team of experts from NASA’s Planetary Defense Coordination Office works diligently to find asteroids that travel near Earth’s orbit.
They’ve released a plan in order to prevent a large-scale asteroid impact, and part of this plan is the DART mission. DART aims to travel to the asteroid Didymos in 2021 to demonstrate the tech that could be used to redirect an asteroid headed for Earth.
It’s a collaboration with the European Space Agency (ESA), whose Hera spacecraft will follow up and observe the results of the impact on the asteroid and map Didymos’s surface and interior structure.
A reduction in seismic noise because of changes in human activity is a boon for geoscientists.
The coronavirus pandemic has brought chaos to lives and economies around the world. But efforts to curb the spread of the virus might mean that the planet itself is moving a little less. Researchers who study Earth’s movement are reporting a drop in seismic noise — the hum of vibrations in the planet’s crust — that could be the result of transport networks and other human activities being shut down. They say this could allow detectors to spot smaller earthquakes and boost efforts to monitor volcanic activity and other seismic events.
A noise reduction of this magnitude is usually only experienced briefly around Christmas, says Thomas Lecocq, a seismologist the Royal Observatory of Belgium in Brussels, where the drop has been observed.
Just as natural events such as earthquakes cause Earth’s crust to move, so do vibrations caused by moving vehicles and industrial machinery. And although the effects from individual sources might be small, together they produce background noise, which reduces seismologists’ ability to detect other signals occurring at the same frequency.
Data from a seismometer at the observatory show that measures to curb the spread of COVID-19 in Brussels caused human-induced seismic noise to fall by about one-third, says Lecocq. The measures included closing schools, restaurants and other public venues from 14 March, and banning all non-essential travel from 18 March (see ‘Seismic noise’).Coronavirus and COVID-19: Keep up to date
The current drop has boosted the sensitivity of the observatory’s equipment, improving its ability to detect waves in the same high frequency range as the noise. The facility’s surface seismometer is now almost as sensitive to small quakes and quarry blasts as a counterpart detector buried in a 100-metre borehole, he adds. “This is really getting quiet now in Belgium.”
If lockdowns continue in the coming months, city-based detectors around the world might be better than usual at detecting the locations of earthquake aftershocks, says Andy Frassetto, a seismologist at the Incorporated Research Institutions for Seismology in Washington DC. “You’ll get a signal with less noise on top, allowing you to squeeze a little more information out of those events,” he says.
The fall in noise could also benefit seismologists who use naturally occurring background vibrations, such as those from crashing ocean waves, to probe Earth’s crust. Because volcanic activity and changing water tables affect how fast these natural waves travel, scientists can study these events by monitoring how long it takes a wave to reach a given detector. A fall in human-induced noise could boost the sensitivity of detectors to natural waves at similar frequencies, says Lecocq, whose team plans to begin testing this. “There’s a big chance indeed it could lead to better measurements,” he says.
Belgian seismologists are not the only ones to notice the effects of lockdown. Celeste Labedz, a graduate student in geophysics at the California Institute of Technology in Pasadena, tweeted that a similar fall in noise had been picked up by a station in Los Angeles. “The drop is seriously wild,” she said.
However, not all seismic monitoring stations will see an effect as pronounced as the one observed in Brussels, says Emily Wolin, a geologist at the US Geological Survey in Albuquerque, New Mexico. Many stations are purposefully located in remote areas or deep boreholes to avoid human noise. These should see a smaller decrease, or no change at all, in the level of high-frequency noise they record, she says.
Scientists have discovered that two unique reservoirs of ancient water once flowed deep beneath the surface of Mars.
It’s hard to believe, but at one time the dry and dusty Red Planet was wet and lush.
“A lot of people have been trying to figure out Mars’ water history,” University of Arizona planetary scientist Jessica Barnes said in a statement. “Like, where did water come from? How long was it in the crust [surface] of Mars? Where did Mars’ interior water come from? What can water tell us about how Mars formed and evolved?”
Barnes and her colleagues examined the isotopes of hydrogen locked inside Mars rocks. Isotopes are variants of an element with different numbers of neutrons. They studied samples they knew were originated from the planet’s crust: the Black Beauty and Allan Hills meteorites.
A recent impact crater on Mars. (NASA/JPL-Caltech/University of Arizona) (NASA/JPL-Caltech/University of Arizona)
Two geochemically different types of Martian volcanic rocks — enriched shergottites and depleted shergottites — contain water with different hydrogen isotope ratios, the researchers found.
Their analysis, which was published today in Nature Geoscience, showed that Mars likely received water from at least two vastly different sources early in its history.
The variability the researchers found seems to imply that Mars, unlike Earth and the moon, never had an ocean of magma completely encompassing the planet.
Yet another good reason to visit this exotic world.
In a new paper published in Science Advances, Hilda Sandström and Martin Rahm from Chalmers University of Technology in Gothenburg, Sweden, consider the possibility of life on Titan—and, more specifically, whether living creatures would need cell membranes to survive.
Membranes are essential for life as we know it because they protect the integrity of a cell’s interior by keeping unwanted substances out. At the same time, they allow critically needed nutrients to come in, and waste products to be discharged. On Earth, cell membranes are built in such a way that they are polar to the outside (to interact well with water, which is a polar solvent), and non-polar to the inside. It’s generally thought that the first membranes were able to self-assemble under Earth’s early environmental conditions.
On Titan the conditions are quite different. Temperatures are extremely cold—between 90 and 94 degrees Kelvin (about -180o C). There is no liquid water anywhere near the surface, and no free oxygen. There are, however, lakes on Titan’s surface consisting of methane and ethane. These hydrocarbons are non-polar. That has led scientists, including me, to suggest that membranes on Titan would be inverted compared to Earth—non-polar on the outside to interact with methane as a solvent and polar to the inside. In an eyebrow-raising paper, James Stevenson and co-authors from Cornell University suggested azotosomes as possible membranes for life on Titan. Azotomes are hypothetical structures that lack the phosphorus and oxygen found in membranes on Earth but contain nitrogen.
Here’s where the new work by Sandström and Rahm comes in. They used computer modeling to determine whether these “polarity-inverted” membranes could self-assemble under the environmental conditions that exist on Titan. The answer was no. Also, the azotosomes were not stable, which at first glance is bad news for life.
However, according to the authors, biological macromolecules would be immobile given the extremely low temperatures on Saturn’s moon. Titan life forms, if they exist, would need to rely on the slow diffusion of smaller molecules. Any membrane, however, would hinder that diffusion, as well as the removal of waste products in the opposite direction. So, the scientists reason, any potential life on Titan may not need a membrane at all.
Personally, I doubt their conclusion. The presence of membranes still appears to me to be essential for maintaining the disequilibrium between the interior of a cell and the outside. Without it, there would be nothing to prevent the loss of valuable organic molecules to the environment. I strongly believe that life—here, on Titan, or anywhere else—requires that the integrity of the smallest unit of life, the cell, has to be maintained.
But I might be incorrect. In any exotic environment like Titan’s, we have to question assumptions that appear to us on Earth as common sense. And I like that the authors have used a computational astrobiological approach to try and push the boundaries of our knowledge. Of course, the best way to answer these questions, as always, is to send missions like Dragonfly to explore Titan up close.Like this article? SIGN UP for our newsletter
What Happens When You Shoot An Asteroid With An ‘Anti-Tank Weapon?
Hayabusa may have left Ryugu, but the science continues to be revealed as the data is analysed, of interest today is the results of the impactor experiment which finally published the images of the explosion and crater formation from the deployable camera. The impact of the 2kg projectile blew a wide hole in the space rock, throwing tons of regolith into space The results of the experiment were published in Science in March 2020 https://science.sciencemag.org/conten…
A comparison of old and new star catalogs shows that some objects seem to have gone missing.
An international research group led by Beatriz Villarroel from the Nordic Institute for Theoretical Physics in Sweden and the Institute for Astrophysics on the Canary Islands reports something strange in the current issue of The Astronomical Journal. They compared star maps from the 1950s with recent surveys, and discovered that 100 previously catalogued stars cannot be found anymore.
The group’s project, called Vanishing and Appearing Sources during a Century of Observations (VASCO) has been comparing mapped stars listed in the U.S. Naval Observatory Catalogue (USNO) B 1.0, dating from the 1950s, with those in another, more recent sky catalog, the Pan-STARRS Data Release (DR1). A total of 150,000 objects were found in the older catalogue (which lists 600 million stars) that did not have a readily identifiable counterpart in the new star survey, even though the Pan-STARRS Data Release includes stars that are five times less bright than the faintest light sources included in USNO. Of these 150,000 anomalies, the authors visually inspected 24,000 candidates and discovered that 100 of these point sources of light appear only in the older star survey. And since then, apparently, they’ve vanished.
Certainly, the most parsimonious explanation for the missing stars is that they are natural phenomena such as extremely flaring dwarf planets, failed supernova, or stars that might directly collapse into a black hole. But there seem to me too many anomalies to explain all the vanished stars as known natural phenomena. In their current paper, the authors themselves discuss the possibility that they’re seeing unknown phenomena, or that the vanished “stars” could be relics of technologically advanced civilizations, particularly the theoretical mega-engineering projects known as Dyson spheres.
Perhaps the missing objects are signs of an advanced civilization. But they’re probably not Dyson spheres. First, it would be hard to explain why and how such a giant construction project, completely shading out the light of the host star, could be done within the short period of less than a century. But more importantly, Brooks Harrop and I showed nearly 10 years ago that “traditional” Dyson spheres are not gravitationally stable. Even if one could be built near a star like our Sun, it would require more total mass than is available in all our Solar System’s planets, moons, and asteroids.
So what are the missing stars? A few might be explained as flaring stars whose brightness dropped below the detection limit, or stars that collapsed directly into a black hole. A large portion, however, might represent new stages in the life cycle of certain stars or new stellar phenomena that have not yet been seen. That by itself would be an exciting topic to investigate.
Another intriguing question: Where are the missing stars? Are they at the same location, just not emitting light anymore? Or perhaps they’ve moved to some other location. If the latter, could some of these represent huge starships, the size of moons or planets, that moved outside the field of view? This, of course, is a highly speculative suggestion. But it would address the hotly discussed Fermi Paradox, and would, in principle, be testable. If these “missing” light sources represent giant starships, some should appear in new star surveys in some other part of the sky. In an ideal case, we might even be able to track their trajectories through time. It would be challenging, no doubt, to pick out such motions against other background movements in space, like those of stars spinning around the center of their galaxy. Nevertheless, my suggestion to the authors is to focus their future work on light sources that suddenly appear in new star surveys, and see whether they can be correlated to the stars that vanished.
In her paper, Villarroel suggests another very promising direction for future research—to search for clusters of missing stars, which, if they exist, could be related to new natural phenomena in a particular region of space, or perhaps to activities of an extraterrestrial civilization. Either way, the authors have turned up something that may become very important for both astrophysical and SETI investigations.
With the coronavirus SARS-CoV-2 on everyone’s mind these days, scientists are working to understand its characteristics. Tung Phan from the University of Pittburgh, for example, found many mutations in the genome of the virus, underlining its genetic diversity and the rapid evolution this pathogen is capable of.
This begs bigger questions, though—like what makes viruses so adaptable, and are they really “alive?”
First, their total number is staggering. It is estimated that there are 10 viruses for every bacterium on Earth. Curtis Suttle from the University of British Columbia in Vancouver compared the number of viruses in the oceans alone to the number of stars in the Universe, which is estimated to be 1023. Viruses outnumber stars by a factor of 10 million. If you lined them all up, that line would be 10 million light years long! To put it on a more conceivable scale, it’s been estimated that each day, more than 700 million viruses, mainly of marine origin, are deposited from Earth’s atmosphere onto every square meter of our planet’s surface.
The diversity of viruses is just as impressive. Some use DNA to pass on genetic information, some use RNA, and some use both during their life cycle. The information carrier can be single-stranded, double-stranded, or double-stranded with some regions being single-stranded. Viruses are like a natural lab seemingly playing around with genetic permutations and combinations. While most viruses are so small that they can only be observed directly with an electron microscope, others, like the giant Mimiviruses, reach the size of bacteria. When I worked in my lab with viruses that kill bacteria—called bacteriophages—we did not count the actual viruses, but the number of bacteria they killed.
Viruses also have benefits. Most of the genetic information on Earth probably resides within them, and viruses are important for transferring genes between different species, increasing genetic diversity and ultimately enhancing evolution and the adaptation of various organisms to new environmental challenges. When life was first arising on Earth, they may have been critical to the evolution of the first cells. I imagine some kind of early Darwinian pond in which viruses and the first cells swapped genes with each other, nearly unimpeded, to come up with critical new adaptations, enhancing the survival of both under challenging early-Earth conditions.
So, are viruses alive?
It depends where we draw the border between non-life and life, which is likely a continuum toward increasing complexity. Does life require cells? Personally, I think that’s a bit—how should I say it?–cell-centric rather than Earth-centric. In my view, viruses have to be counted as alive. We should recognize them as a fourth domain of life and not dismiss them, if only because they do in fact reproduce outside their own “bodies.” The parasitic bacteria that cause chlamydia are considered to be living. One hypothesis for the origin of viruses says that they, or at least some of them, could have evolved from bacteria that lost any genes not needed for parasitism. If so, could we say they “evolved” from living back to non-living?
Another thing I find intriguing: The more common RNA viruses—like the coronavirus behind the current pandemic—have typically smaller genome sizes than DNA viruses, apparently because of a higher error-rate when replicating. Too many errors have the effect that natural selection disfavors them. It also limits the maximum size of these viruses.
This seems to support the hypothesis that life originated with an RNA world, and that for very primitive life RNA worked perfectly fine to pass on genetic information. As organisms grew in size, they required larger genomes and needed to transfer more information. At that point DNA outcompeted RNA as a type of informational code. But RNA survives as an essential part of terrestrial biology, as we’re seeing with the coronavirus SARS-CoV-2.
Do microbes live elsewhere in our solar system? Signs point to yes….
The Atacama Desert in Chile is one of the most arid and uninhabitable places on earth. Decades can pass without any rainfall. Yet researchers have managed to find life there: microbes. This discovery has inspired hope that there may perhaps be life on Mars.
Uninhabitable The international research team found a number of bacteria in the bone-dry soil. Contrary to other species of bacteria, though, these single-celled organisms seemed to be inactive. For quite some time, they were assumed to be dead or perhaps dying bacteria that had been carried there by the wind from other places. However, subsequent research showed that they are specialised bacteria that survive in a form of deep sleep when there is a lack of water. When it rains, they awaken and begin to divide actively.
Chance of rain: 1 in a 1,000 When the researchers first arrived at the desert in 2015, something unusual happened. It began to rain. This exceptional occurrence led to an explosion of biological activity. Using sterile spoons and surgical precision, soil samples were taken at various depths. Near the surface, Geodermatophilaceae and Rubrobacter bacteria were found with a resistance to dehydration and UV radiation. At deeper levels, where saline levels were higher, so-called halophile (‘salt-loving’) microbes such as Betaproteobacteria were encountered.
Mars Researchers think that these micro-organisms may well be able to sleep for hundreds or even thousands of years. The conditions closely resemble the planet Mars. Although conditions there are currently arid and cold, this situation was not always the case. Billions of years ago, Mars had small oceans and lakes that may have hosted early life forms. These life forms perhaps adapted themselves to current conditions on Mars.
Water Frozen lakes are known to exist on Mars, while recent research suggests that there may even be snowfall. This fact means that circumstances exist in which humidity on Mars could increase. As the research in the Atacama Desert has shown, moisture could revive the microbes. To this end, the team would like to conduct research in Don Juan Pond on Antarctica. Since the shallow lake has a salinity of 40%, it does not even freeze over at −50°C.
Saturn’s icy moon Mars is not the only place in our solar system where life could exist. There are any number of places where moisture can be found. Austrian and German researchers have used laboratory experiments to show that there could be microbes living on Saturn’s icy moon Enceladus. Cassini, the American spacecraft which explored the planets, showed that there were geysers spewing methane into the atmosphere from a subterranean ocean. According to the researchers, this methane gas possibly is being produced by micro-organisms. They mimicked the circumstances in this ocean within the laboratory. The methane-producing archaea Methanothermococcus okinawensis, found on earth in extremely hot water near deep-sea hydrothermal vents, would easily be able to live in these circumstances.
Social distancing Apollo 11 style, how calm and collected they were! In 1969, no one knew if they’d bring home from the moon a bacterium or virus that could infect the world. If they can do three weeks, we can do two at home.
The headlines in the wake of Apollo 11 could have been very, very different.
It would have been the ultimate contingency of Apollo 11: What if the astronauts returning home unleashed upon Earth something dangerous and foreign to science — moon germs?
Before Apollo 11 set out, NASA couldn’t be positive that, if bits of dust or potential microorganisms got loose back home, life on Earth would be safe. Needless to say, accidentally setting a lunar plague loose on the inhabitants of Earth would have erased all the good publicity garnered by accomplishing the moon landing in the first place. Just in case, in addition to the protections they were establishing to make sure the moon rocks remained free of terrestrial contamination, NASA decided to establish a three-week quarantine for the crew of Apollo 11.ADVERTISING
“Initially, NASA thought that all they really needed was a clean room to handle the packaging of the lunar samples in a vacuum,” Judith Hayes, chief of NASA’s biomedical research and environmental sciences division, told Space.com. “They started really wrapping their head around this, is my understanding. They said, ‘We’ve really never done this before, so we’re not really sure,’ even though I think most of the scientists didn’t firmly believe that there might be a risk.”
The quarantine was treated all along as a better-safe-than-sorry operation. The day before Apollo 11 splashed down, support staff had already entered quarantine in Houston to prepare for the crew’s arrival, and The New York Times reported: “Twelve men are in absolute quarantine here because of something that probably does not exist.”
The problem was, though, if that threat turned out to be a reality, things would get very ugly. “The quarantine program was created out of an abundance of caution,” Jason Schwartz, a historian of medicine at the Yale School of Public Health, told Space.com. “You had a very, very small risk of something that could be very, very, very significant.”
When the Apollo missions were launching, public health professionals had generally moved on from crude tools like quarantines, he said. “By the 1960s, we were really in the golden age of vaccines and immunizations,” Schwartz said, particularly for diseases like polio, measles and mumps. “There was great optimism that the war against infectious diseases was being won,” and he said that could have contributed to a fear of backsliding if Apollo went very wrong.
And the prospect of moon germs also mirrored a real public health concern at the time, of novel pathogens that the population had never had a chance to build an immunity to. It’s a fear that remains with us today, which was sparked at the time by, for example, new influenza strains popping up on occasion. If something nasty hitched a ride back from the moon, it would have been the epitome of a novel pathogen. And, it would have driven doctors and public health practitioners way beyond their comfort zone.
“This was a different story than most public health efforts at the time, because typically, when we think about treatments, antibiotics, vaccines, quarantines, we’re thinking about known viruses or bacteria with distinct symptoms, distinct modes of transmission that we know about and we can apply that knowledge to figure out how to tailor the public health response,” Schwartz said. “In this case, it was responding to an unknowable, responding to a very slim but still nonzero uncertainty. How do you tailor a public health response when you’re not sure what exactly you’re concerned about or what it looks like or how it might affect humans at all?”
In the absence of any precisely honed tools to combat the potential threat, NASA used the blunt approach of a quarantine. The details of the plan were based on tackling a disease like the plague, according to a 1999 oral history given by Charles Berry, who was in charge of medical operations during Apollo.
The quarantine procedures began three weeks before launch, when the astronauts went into isolation to reduce the odds they would catch anything that NASA would later need to identify as terrestrial or lunar. For Apollo 11, Berry said, the prelaunch quarantine was nearly derailed by President Richard Nixon, who wanted to eat dinner with the crew the evening before launch. It was Berry’s job to explain why that simply wasn’t an option — the closest he said he believed he ever came to being fired.
“If [the astronauts] came down with anything, whatever it was, a cough, a sniffle, or anything else, we were going to have to prove that it didn’t come from the moon,” Berry told the interviewer. “So I think it would be pretty stupid to let somebody just walk into that situation. It would have been a total breakdown of the program.”
Nixon shooed off and quarantine preserved, the trio of astronauts climbed aboard their rocket and blasted off on the historic journey. As they wrapped up their time on the moon, Neil Armstrong and Buzz Aldrin abandoned some of their equipment, including their boot covers, in part to reduce the odds they would bring back any lunar threats. The 21-day quarantine clock began ticking as soon as the pair stepped off the moon and closed the hatch on the lunar module.
They rejoined their colleague, Michael Collins, and headed back to Earth, splashing down in the Pacific Ocean on July 24. But the astronauts still had more than two weeks of quarantine left, and NASA had decided it wasn’t safe to simply hoist the newly returned command module onto the aircraft carrier sent to fetch the astronauts.
The rescue crew had to send a swimmer to the spacecraft to open the hatch and throw in biological isolation garments for the astronauts to put on — spacesuits for Earth use only, essentially, with tightly woven fabric that would contain particles; rubber gloves; and a built-in breathing system.
That made splashdown the biggest weakness in the quarantine system, as Collins has said in interviews looking back at the mission. “When you open that hatch, we had stuff come into the air, without any question about it,” Berry said in his oral history. “You know, if it had been lunar plague, I don’t know what would have happened. I didn’t believe we were going to have lunar plague, but I couldn’t go on the basis that we weren’t.”
Once the astronauts had donned their isolation suits, they climbed on board the ship sent to rescue them, then into the Mobile Quarantine Facility, a trailer NASA had converted to house them. The crew spent 2.5 days in the trailer as they sailed to port in Hawaii, then boarded a plane to Houston. Back in NASA’s astronaut headquarters, the trailer was connected to the Lunar Receiving Laboratory, a special facility the agency had built at what is now the Johnson Space Center.
The building included quarantine quarters as well as lab space for preparing and studying moon rocks. The crew section was large enough to hold more than 100 people if something went very wrong, Hayes said, and included a kitchen, a lounge, a library and a collection of surgical and medical examination rooms.Advertisement
“It was, I think, quite comfortable,” Hayes said. “Talking to the crews from back then and the flight surgeon, they did say that — you know, it wasn’t bad. After spending time in a capsule, being in the quarantine facility was quite comfortable.” Armstrong even celebrated his birthday in the quarantine building.
The crew and about 20 companions waited out the rest of the quarantine period in the facility, without particular concerns about the possibility they were infected. “I got the impression that … the [astronauts] were not worried,” Hayes said. “They had daily exams from their flight surgeons … they were being carefully watched by the flight surgeons and the scientists in the quarantine.” Scientists were also monitoring mice that had been exposed to lunar samples in case they showed signs of distress, but all did well.
But by the end of the 21 days, newspapers reported that the astronauts were ready to get back to exploring Earth. “I’m ready any time they want to open that door,” Aldrin said according to The New York Times. “Take my blood. Marvelous idea. Why didn’t I think of that sooner?” the paper reported Collins said when it transpired that a blood test would shorten quarantine by a few hours.
NASA had planned to institute the quarantine for Apollo 11, 12, 13 and 14, then reevaluate the situation. The Apollo 13 quarantine was canceled after the crewmembers were forced to skip the moon landing maneuver. During the first couple years of studying moon rocks in terrestrial labs, occasional lapses in safety protocols also sent scientists into observation or quarantine.Advertisement
But after Apollo 14, NASA decided that Earth was safe from lunar bugs. The lunar receiving lab’s sample-processing side remained active until a new building was constructed and the moon rocks were moved out. Then, the building was turned over to NASA’s life sciences division, which is how Hayes ended up spending decades working in its labs and uncovering its history.
Now, her department has moved out as well. “I was the last one to shut the lights out and lock the door when we moved out of the Lunar Receiving Lab, and now it sits empty,” Hayes said.
According to NASA spokesperson Noah Michelsohn, the building is slated for demolition, with a new sample-processing facility due to be built before the asteroid missions OSIRIS-REx and Hayabusa2 bring back new, precious space rocks starting late next year. Hayes said she wishes she had appreciated the facility more when she first joined NASA, since it tells such a compelling story about the Apollo program and of spaceflight in general.
“It’s kind of amazing, all the things they thought of and pulled together to do this,” Hayes said. “I imagine when we go back to the moon, we’ll have to do some similar things, not necessarily for the crew but handling samples and the experiments that’ll be done.”
Buddy_Nath / PixabayTuesday, March 17, 2020 6:10 AM UTC
Being able to see comets is not as anticipated compared to seeing meteor showers, which occur at least once every month by a different group of meteorites. Now, experts believe one particular comet, the Atlas comet, will shine as bright as the moon when it approaches the sun.
Express reports that the comet, which is also referred to as C/2019 Y4, is expected to shine brightly when it gets closer to the Sun. The comet is currently within the vicinity of Mars’ orbit and is expected to go nearer by the latter part of May. By this time, ATLAS will be 0.25 astronomical units away from the Sun, but the distance will shorten the closer it gets.
When ATLAS approaches the Sun, scientists believe that the comet will shine as bright as a waxing crescent moon. According to the Space Weather website, “The comet is about as bright as an 8th or 9th magnitude star. That’s too dim to see with the naked eye but consider this: The comet is hundreds of times bigger than astronomers predicted when it was discovered 4 months ago…” and that by May when the comet is closer to the Sun, the comet will be as bright as a 1st magnitude star or a waxing crescent moon.
For those who already want to see a glimpse of ATLAS before May, astronomers or space enthusiasts will already be able to see the comet with a mid-sized backyard telescope. It is also encouraged to observe the comet as it gets brighter the closer it gets to the Sun and look out for possible outbursts that may happen in the coming weeks due to the volatile material within the comet getting exposed by the increasing sunlight.
Although comets are usually observed, there is a possibility that a comet may decide to strike Earth instead of passing by it. Asteroid and comet expert Dr. Steve Chesley previously revealed what makes a comet dangerous, especially if ever it decides to strike. Dr. Chesley noted how comets usually were seen as a bad omen all throughout history and explained that because comets move faster than asteroids, they will cause more damage.
Aside from the speed, the size of the comet is also a concern, as Dr. Chesley revealed that comets coming from deep space would most likely be much larger.
Should we be searching for post-biological aliens?
In a new paper published in The International Journal of Astrobiology, Joseph Gale from The Hebrew University of Jerusalem and co-authors make the point that recent advances in artificial intelligence (AI)—particularly in pattern recognition and self-learning—will likely result in a paradigm shift in the search for extraterrestrial intelligent life.
While futurist Ray Kurzweil predicted 15 years ago that the singularity—the time when the abilities of a computer overtake the abilities of the human brain—will occur in about 2045, Gale and his co-authors believe this event may be much more imminent, especially with the advent of quantum computing. It’s already been four years since the program AlphaGO, fortified with neural networks and learning modes, defeated Lee Sedol, the Go world champion. The strategy game StarCraft II may be the next to have a machine as reigning champion.
If we look at the calculating capacity of computers and compare it to the number of neurons in the human brain, the singularity could be reached as soon as the early 2020s. However, a human brain is “wired” differently than a computer, and that may be the reason why certain tasks that are simple for us are still quite challenging for today’s AI. Also, the size of the brain or the number of neurons don’t equate to intelligence. For example, whales and elephants have more than double the number of neurons in their brain, but are not more intelligent than humans.
The authors don’t know when the singularity will come, but come it will. When this occurs, the end of the human race might very well be upon us, they say, citing a 2014 prediction by the late Stephen Hawking. According to Kurzweil, humans may then be fully replaced by AI, or by some hybrid of humans and machines.
What will this mean for astrobiology? Not much, if we’re searching only for microbial extraterrestrial life. But it might have a drastic impact on the search for extraterrestrial intelligent life (SETI). If other civilizations are similar to ours but older, we would expect that they already moved beyond the singularity. So they wouldn’t necessarily be located on a planet in the so-called habitable zone. As the authors point out, such civilizations might prefer locations with little electronic noise in a dry and cold environment, perhaps in space, where they could use superconductivity for computing and quantum entanglement as a means of communication.
I think it also is still unclear whether there is something special enough about the human brain’s ability to process information that casts doubt on whether AI can surpass our abilities in all relevant areas, especially in achieving consciousness. Might there be something unique to biological brains after millions and millions of years of evolution that computers cannot achieve? If not, the authors are correct that reaching the singularity could be humanity’s greatest and last advance.
Buried inside data that NASA’s iconic Voyager 2 spacecraft gathered at Uranus more than 30 years ago is the signature of a massive bubble that may have stolen a blob of the planet’s gassy atmosphere.
That’s according to scientists who analyzed archived Voyager 2 observations of the magnetic field around Uranus. These measurements had been studied before, but only using a relatively coarse view. In the new research, scientists instead looked at those measurements every two seconds. That detail showed what had previously been missed: an abrupt zigzag in the magnetic field readings that lasted just one minute of the spacecraft’s 45-hour journey past Uranus.ADVERTISING
The tiny wobble in the Voyager 2 data represents something much larger since the spacecraft was flying so fast. Specifically, the scientists behind the new research believe the zigzag marks a plasmoid, a type of structure that wasn’t understood particularly well at the time of the flyby in January 1986.
But by now, plasmoids have earned scientists’ respect. A plasmoid is a massive bubble of plasma, which is a soup of charged particles. Plasmoids can break off from the tip of the sleeve of magnetism surrounding a planet like a teardrop.
Scientists have studied these structures at Earth and nearby planets, but never at Uranus or its neighbor Neptune, since Voyager 2 is the only spacecraft to date ever to visit those planets.
Scientists want to know about plasmoids because these structures can pull charged particles out of a planet’s atmosphere and fling them into space. And if you change a planet’s atmosphere, you change the planet itself. And Uranus’ situation is particularly complicated because the planet rotates on its side and its magnetic field is skewed from both that axis and the plane all the planets lie in.
Because Voyager 2 flew straight through this plasmoid, scientists could use the archived data to measure the structure, which they believe was about 250,000 miles (400,000 kilometers) across and could have stretched 127,000 miles (204,000 km) long, according to a NASA statement.
Ideally, scientists would piece together more observations of Uranus’ magnetic field, enough to better understand how this phenomenon has shaped the planet over time. But that will require another spacecraft visit the strange sideways world.
The research is described in a paper published in August in the journal Geophysical Review Letters. NASA announced the finding on Wednesday (March 25).
March 24, 2020: No one knows how big the icy core of Comet ATLAS (C/2019 Y4) might be–possibly no wider than a few kilometers. One thing’s for sure, though, the comet’s atmosphere is huge. New images from amateur astronomers around the world show that ATLAS’s gaseous envelope has ballooned in diameter to ~720,000 km–about half as wide as the sun.
“Comet ATLAS’s coma (atmosphere) is approximately 15 arcminutes in diameter,” reports Michael Jäger of Weißenkirchen, Austria, who took the picture, above, on March 18th. “Its newly-formed tail is about the same size.”
Other astronomers are getting similar results. 15 arcminutes = a quarter of a degree. Given Comet ATLAS’s distance of 1.1 AU on March 18th, that angle corresponds to a physical size of 720,000 km.
On the scale of big things in the solar system, Comet ATLAS falls somewhere between the sun (1,392,000 km diameter) and Jupiter (139,820 km). It’s not unusual for comets to grow so large. While their icy solid cores are typically mere kilometers in diameter, they can spew prodigious amounts of gas and dust into space, filling enormous volumes. In the fall of 2007, Comet 17P/Holmes partially exploded and, for a while, had an atmosphere even larger than the sun. The Great Comet of 1811 also had a sun-sized coma. Whether Comet ATLAS will eventually rival those behemoths of the past remains to be seen.
Right now, Comet ATLAS is certainly the biggest green thing in the Solar System. Its verdant hue comes from diatomic carbon, C2, a molecule commonly found in comets. Gaseous C2 emits a beautiful green glow in the near-vacuum of space.
Currently, Comet ATLAS is shining like an 8th magnitude star–invisible to the unaided eye but an easy target for backyard telescopes. The comet is brightening rapidly as it comes closer to Earth and the sun. By late May it could rival Venus in the evening twilight sky. Stay tuned!
Are we in danger of being erased from the universe? Here we look at the factors that could doom humanity: natural disasters, human-triggered cataclysms, willful self-destruction, and greater forces directed against us.
We’ve had a good run of it. In the 500,000 years Homo sapiens has roamed the land we’ve built cities, created complex languages, and sent robotic scouts to other planets. It’s difficult to imagine it all coming to an end. Yet 99 percent of all species that ever lived have gone extinct, including every one of our hominid ancestors. In 1983, British cosmologist Brandon Carter framed the “Doomsday argument,” a statistical way to judge when we might join them. If humans were to survive a long time and spread through the galaxy, then the total number of people who will ever live might number in the trillions. By pure odds, it’s unlikely that we would be among the very first hundredth of a percent of all those people. Or turn the argument around: How likely is it that this generation will be the one unlucky one? Something like one fifth of all the people who have ever lived are alive today. The odds of being one of the people to witness doomsday are highest when there is the largest number of witnesses around—so now is not such an improbable time.
Human activity is severely disrupting almost all life on the planet, which surely doesn’t help matters. The current rate of extinctions is, by some estimates, 10,000 times the average in the fossil record. At present, we may worry about snail darters and red squirrels in abstract terms. But the next statistic on the list could be us.
1. Asteroid impact Once a disaster scenario gets the cheesy Hollywood treatment, it’s hard to take it seriously. But there is no question that a cosmic interloper will hit Earth, and we won’t have to wait millions of years for it to happen. In 1908 a 200-foot-wide comet fragment slammed into the atmosphere and exploded over the Tunguska region in Siberia, Russia, with nearly 1,000 times the energy of the atomic bomb dropped on Hiroshima. Astronomers estimate similar-sized events occur every one to three centuries. Benny Peiser, an anthropologist-cum-pessimist at Liverpool John Moores University in England, claims that impacts have repeatedly disrupted human civilization. As an example, he says one killed 10,000 people in the Chinese city of Chi’ing-yang in 1490. Many scientists question his interpretations: Impacts are most likely to occur over the ocean, and small ones that happen over land are most likely to affect unpopulated areas. But with big asteroids, it doesn’t matter much where they land. Objects more than a half-mile wide—which strike Earth every 250,000 years or so—would touch off firestorms followed by global cooling from dust kicked up by the impact. Humans would likely survive, but civilization might not. An asteroid five miles wide would cause major extinctions, like the one that may have marked the end of the age of dinosaurs. For a real chill, look to the Kuiper belt, a zone just beyond Neptune that contains roughly 100,000 ice-balls more than 50 miles in diameter. The Kuiper belt sends a steady rain of small comets earthward. If one of the big ones headed right for us, that would be it for pretty much all higher forms of life, even cockroaches.
2. Gamma-ray burst If you could watch the sky with gamma-ray vision, you might think you were being stalked by cosmic paparazzi. Once a day or so, you would see a bright flash appear, briefly outshine everything else, then vanish. These gamma-ray bursts, astrophysicists recently learned, originate in distant galaxies and are unfathomably powerful—as much as 10 quadrillion (a one followed by 16 zeros) times as energetic as the sun. The bursts probably result from the merging of two collapsed stars. Before the cataclysmal event, such a double star might be almost completely undetectable, so we’d likely have no advance notice if one is lurking nearby. Once the burst begins, however, there would be no missing its fury. At a distance of 1,000 light-years—farther than most of the stars you can see on a clear night—it would appear about as bright as the sun. Earth’s atmosphere would initially protect us from most of the burst’s deadly X rays and gamma rays, but at a cost. The potent radiation would cook the atmosphere, creating nitrogen oxides that would destroy the ozone layer. Without the ozone layer, ultraviolet rays from the sun would reach the surface at nearly full force, causing skin cancer and, more seriously, killing off the tiny photosynthetic plankton in the ocean that provide oxygen to the atmosphere and bolster the bottom of the food chain. All the gamma-ray bursts observed so far have been extremely distant, which implies the events are rare. Scientists understand so little about these explosions, however, that it’s difficult to estimate the likelihood of one detonating in our galactic neighborhood.
3. Collapse of the vacuum In the book Cat’s Cradle, Kurt Vonnegut popularized the idea of “ice-nine,” a form of water that is far more stable than the ordinary kind, so it is solid at room temperature. Unleash a bit of it, and suddenly all water on Earth transforms to ice-nine and freezes solid. Ice-nine was a satirical invention, but an abrupt, disastrous phase transition is a possibility. Very early in the history of the universe, according to a leading cosmological model, empty space was full of energy. This state of affairs, called a false vacuum, was highly precarious. A new, more stable kind of vacuum appeared and, like ice-nine, it quickly took over. This transition unleashed a tremendous amount of energy and caused a brief runaway expansion of the cosmos. It is possible that another, even more stable kind of vacuum exists, however. As the universe expands and cools, tiny bubbles of this new kind of vacuum might appear and spread at nearly the speed of light. The laws of physics would change in their wake, and a blast of energy would dash everything to bits. “It makes for a beautiful story, but it’s not very likely,” says Piet Hut of the Institute for Advanced Studies in Princeton, New Jersey. He says he worries more about threats that scientists are more certain of—such as rogue black holes.
4. Rogue black holes Our galaxy is full of black holes, collapsed stellar corpses just a dozen miles wide. How full? Tough question. After all, they’re called black holes for a reason. Their gravity is so strong they swallow everything, even the light that might betray their presence. David Bennett of Notre Dame University in Indiana managed to spot two black holes recently by the way they distorted and amplified the light of ordinary, more distant stars. Based on such observations, and even more on theoretical arguments, researchers guesstimate there are about 10 million black holes in the Milky Way. These objects orbit just like other stars, meaning that it is not terribly likely that one is headed our way. But if a normal star were moving toward us, we’d know it. With a black hole there is little warning. A few decades before a close encounter, at most, astronomers would observe a strange perturbation in the orbits of the outer planets. As the effect grew larger, it would be possible to make increasingly precise estimates of the location and mass of the interloper. The black hole wouldn’t have to come all that close to Earth to bring ruin; just passing through the solar system would distort all of the planets’ orbits. Earth might get drawn into an elliptical path that would cause extreme climate swings, or it might be ejected from the solar system and go hurtling to a frigid fate in deep space.
5. Giant solar flares Solar flares—more properly known as coronal mass ejections—are enormous magnetic outbursts on the sun that bombard Earth with a torrent of high-speed subatomic particles. Earth’s atmosphere and magnetic field negate the potentially lethal effects of ordinary flares. But while looking through old astronomical records, Bradley Schaefer of Yale University found evidence that some perfectly normal-looking, sunlike stars can brighten briefly by up to a factor of 20. Schaefer believes these stellar flickers are caused by superflares, millions of times more powerful than their common cousins. Within a few hours, a superflare on the sun could fry Earth and begin disintegrating the ozone layer (see #2). Although there is persuasive evidence that our sun doesn’t engage in such excess, scientists don’t know why superflares happen at all, or whether our sun could exhibit milder but still disruptive behavior. And while too much solar activity could be deadly, too little of it is problematic as well. Sallie Baliunas at the Harvard-Smithsonian Center for Astrophysics says many solar-type stars pass through extended quiescent periods, during which they become nearly 1 percent dimmer. That might not sound like much, but a similar downturn in the sun could send us into another ice age. Baliunas cites evidence that decreased solar activity contributed to 17 of the 19 major cold episodes on Earth in the last 10,000 years.
6. Reversal of Earth’s magnetic field Every few hundred thousand years Earth’s magnetic field dwindles almost to nothing for perhaps a century, then gradually reappears with the north and south poles flipped. The last such reversal was 780,000 years ago, so we may be overdue. Worse, the strength of our magnetic field has decreased about 5 percent in the past century. Why worry in an age when GPS has made compasses obsolete? Well, the magnetic field deflects particle storms and cosmic rays from the sun, as well as even more energetic subatomic particles from deep space. Without magnetic protection, these particles would strike Earth’s atmosphere, eroding the already beleaguered ozone layer (see #5). Also, many creatures navigate by magnetic reckoning. A magnetic reversal might cause serious ecological mischief. One big caveat: “There are no identifiable fossil effects from previous flips,” says Sten Odenwald of the NASA Goddard Space Flight Center. “This is most curious.” Still, a disaster that kills a quarter of the population, like the Black Plague in Europe, would hardly register as a blip in fossil records.
7. Flood-basalt volcanism In 1783, the Laki volcano in Iceland erupted, spitting out three cubic miles of lava. Floods, ash, and fumes wiped out 9,000 people and 80 percent of the livestock. The ensuing starvation killed a quarter of Iceland’s population. Atmospheric dust caused winter temperatures to plunge by 9 degrees in the newly independent United States. And that was just a baby’s burp compared with what the Earth can do. Sixty-five million years ago, a plume of hot rock from the mantle burst through the crust in what is now India. Eruptions raged century after century, ultimately unleashing a quarter-million cubic miles of lava—the Laki eruption 100,000 times over. Some scientists still blame the Indian outburst, not an asteroid, for the death of the dinosaurs. An earlier, even larger event in Siberia occurred just about the time of the Permian-Triassic extinction, the most thorough extermination known to paleontology. At that time 95 percent of all species were wiped out.
Sulfurous volcanic gases produce acid rains. Chlorine-bearing compounds present yet another threat to the fragile ozone layer—a noxious brew all around. While they are causing short-term destruction, volcanoes also release carbon dioxide that yields long-term greenhouse-effect warming.The last big pulse of flood-basalt volcanism built the Columbia River plateau about 17 million years ago. We’re ripe for another.
8. Global epidemics If Earth doesn’t do us in, our fellow organisms might be up to the task. Germs and people have always coexisted, but occasionally the balance gets out of whack. The Black Plague killed one European in four during the 14th century; influenza took at least 20 million lives between 1918 and 1919; the AIDS epidemic has produced a similar death toll and is still going strong. From 1980 to 1992, reports the Centers for Disease Control and Prevention, mortality from infectious disease in the United States rose 58 percent. Old diseases such as cholera and measles have developed new resistance to antibiotics. Intensive agriculture and land development is bringing humans closer to animal pathogens. International travel means diseases can spread faster than ever. Michael Osterholm, an infectious disease expert who recently left the Minnesota Department of Health, described the situation as “like trying to swim against the current of a raging river.” The grimmest possibility would be the emergence of a strain that spreads so fast we are caught off guard or that resists all chemical means of control, perhaps as a result of our stirring of the ecological pot. About 12,000 years ago, a sudden wave of mammal extinctions swept through the Americas. Ross MacPhee of the American Museum of Natural History argues the culprit was extremely virulent disease, which humans helped transport as they migrated into the New World.
9. Global warming The Earth is getting warmer, and scientists mostly agree that humans bear some blame. It’s easy to see how global warming could flood cities and ruin harvests. More recently, researchers like Paul Epstein of Harvard Medical School have raised the alarm that a balmier planet could also assist the spread of infectious disease by providing a more suitable climate for parasites and spreading the range of tropical pathogens (see #8). That could include crop diseases which, combined with substantial climate shifts, might cause famine. Effects could be even more dramatic. At present, atmospheric gases trap enough heat close to the surface to keep things comfortable. Increase the global temperature a bit, however, and there could be a bad feedback effect, with water evaporating faster, freeing water vapor (a potent greenhouse gas), which traps more heat, which drives carbon dioxide from the rocks, which drives temperatures still higher. Earth could end up much like Venus, where the high on a typical day is 900 degrees Fahrenheit. It would probably take a lot of warming to initiate such a runaway greenhouse effect, but scientists have no clue where exactly the tipping point lies.
10. Ecosystem collapse Images of slaughtered elephants and burning rain forests capture people’s attention, but the big problem—the overall loss of biodiversity—is a lot less visible and a lot more serious. Billions of years of evolution have produced a world in which every organism’s welfare is intertwined with that of countless other species. A recent study of Isle Royale National Park in Lake Superior offers an example. Snowy winters encourage wolves to hunt in larger packs, so they kill more moose. The decline in moose population allows more balsam fir saplings to live. The fir trees pull carbon dioxide out of the atmosphere, which in turn influences the climate. It’s all connected. To meet the demands of the growing population, we are clearing land for housing and agriculture, replacing diverse wild plants with just a few varieties of crops, transporting plants and animals, and introducing new chemicals into the environment. At least 30,000 species vanish every year from human activity, which means we are living in the midst of one of the greatest mass extinctions in Earth’s history. Stephen Kellert, a social ecologist at Yale University, sees a number of ways people might upset the delicate checks and balances in the global ecology. New patterns of disease might emerge (see #8), he says, or pollinating insects might become extinct, leading to widespread crop failure. Or as with the wolves of Isle Royale, the consequences might be something we’d never think of, until it’s too late.
11. Biotech disaster While we are extinguishing natural species, we’re also creating new ones through genetic engineering. Genetically modified crops can be hardier, tastier, and more nutritious. Engineered microbes might ease our health problems. And gene therapy offers an elusive promise of fixing fundamental defects in our DNA. Then there are the possible downsides. Although there is no evidence indicating genetically modified foods are unsafe, there are signs that the genes from modified plants can leak out and find their way into other species. Engineered crops might also foster insecticide resistance. Longtime skeptics like Jeremy Rifkin worry that the resulting superweeds and superpests could further destabilize the stressed global ecosystem (see #9). Altered microbes might prove to be unexpectedly difficult to control. Scariest of all is the possibility of the deliberate misuse of biotechnology. A terrorist group or rogue nation might decide that anthrax isn’t nasty enough and then try to put together, say, an airborne version of the Ebola virus. Now there’s a showstopper.
12. Particle accelerator mishap Theodore Kaczynski, better known as the Unabomber, raved that a particle accelerator experiment could set off a chain reaction that would destroy the world. Surprisingly, many sober-minded physicists have had the same thought. Normally their anxieties come up during private meetings, amidst much scribbling on the backs of used envelopes. Recently the question went public when London’s Sunday Times reported that the Relativistic Heavy Ion Collider (RHIC) on Long Island, New York, might create a subatomic black hole that would slowly nibble away our planet. Alternately, it might create exotic bits of altered matter, called strangelets, that would obliterate whatever ordinary matter they met. To assuage RHIC’s jittery neighbors, the lab’s director convened a panel that rejected both scenarios as pretty much impossible. Just for good measure, the panel also dismissed the possibility that RHIC would trigger a phase transition in the cosmic vacuum energy (see #3). These kinds of reassurances follow the tradition of the 1942 “LA-602” report, a once-classified document that explained why the detonation of the first atomic bomb almost surely would not set the atmosphere on fire. The RHIC physicists did not, however, reject the fundamental possibility of the disasters. They argued that their machine isn’t nearly powerful enough to make a black hole or destabilize the vacuum. Oh, well. We can always build a bigger accelerator.
13. Nanotechnology disaster Before you’ve even gotten the keyboard dirty, your home computer is obsolete, largely because of incredibly rapid progress in miniaturizing circuits on silicon chips. Engineers are using the same technology to build crude, atomic-scale machines, inventing a new field as they go called nanotechnology. Within a few decades, maybe sooner, it should be possible to build microscopic robots that can assemble and replicate themselves. They might perform surgery from inside a patient, build any desired product from simple raw materials, or explore other worlds. All well and good if the technology works as intended. Then again, consider what K. Eric Drexler of the Foresight Institute calls the “grey goo problem” in his book Engines of Creation, a cult favorite among the nanotech set. After an industrial accident, he writes, bacteria-sized machines, “could spread like blowing pollen, replicate swiftly, and reduce the biosphere to dust in a matter of days.” And Drexler is actually a strong proponent of the technology. More pessimistic souls, such as Bill Joy, a cofounder of Sun Microsystems, envision nano-machines as the perfect precision military or terrorist tools.
14. Environmental toxins From Donora, Pennsylvania, to Bhopal, India, modern history abounds with frightening examples of the dangers of industrial pollutants. But the poisoning continues. In major cities around the world, the air is thick with diesel particulates, which the National Institutes of Health now considers a carcinogen. Heavy metals from industrial smokestacks circle the globe, even settling in the pristine snows of Antarctica. Intensive use of pesticides in farming guarantees runoff into rivers and lakes. In high doses, dioxins can disrupt fetal development and impair reproductive function—and dioxins are everywhere. Your house may contain polyvinyl chloride pipes, wallpaper, and siding, which belch dioxins if they catch fire or are incinerated. There are also the unknown risks to think about. Every year NIH adds to its list of cancer-causing substances—the number is up to 218. Theo Colburn of the World Wildlife Fund argues that dioxins and other, similar chlorine-bearing compounds mimic the effects of human hormones well enough that they could seriously reduce fertility. Many other scientists dispute her evidence, but if she’s right, our chemical garbage could ultimately threaten our survival.
15. Global war Together, the United States and Russia still have almost 19,000 active nuclear warheads. Nuclear war seems unlikely today, but a dozen years ago the demise of the Soviet Union also seemed rather unlikely. Political situations evolve; the bombs remain deadly. There is also the possibility of an accidental nuclear exchange. And a ballistic missile defense system, given current technology, will catch only a handful of stray missiles—assuming it works at all. Other types of weaponry could have global effects as well. Japan began experimenting with biological weapons after World War I, and both the United States and the Soviet Union experimented with killer germs during the cold war. Compared with atomic bombs, bioweapons are cheap, simple to produce, and easy to conceal. They are also hard to control, although that unpredictability could appeal to a terrorist organization. John Leslie, a philosopher at the University of Guelph in Ontario, points out that genetic engineering might permit the creation of “ethnic” biological weapons that are tailored to attack primarily one ethnic group (see #11).
16. Robots take over People create smart robots, which turn against us and take over the world. Yawn. We’ve seen this in movies, TV, and comic books for decades. After all these years, look around and still—no smart robots. Yet Hans Moravec, one of the founders of the robotics department of Carnegie Mellon University, remains a believer. By 2040, he predicts, machines will match human intelligence, and perhaps human consciousness. Then they’ll get even better. He envisions an eventual symbiotic relationship between human and machine, with the two merging into “postbiologicals” capable of vastly expanding their intellectual power. Marvin Minsky, an artificial-intelligence expert at MIT, foresees a similar future: People will download their brains into computer-enhanced mechanical surrogates and log into nearly boundless files of information and experience. Whether this counts as the end of humanity or the next stage in evolution depends on your point of view. Minsky’s vision might sound vaguely familiar. After the first virtual-reality machines hit the marketplace around 1989, feverish journalists hailed them as electronic LSD, trippy illusion machines that might entice the user in and then never let him out. Sociologists fretted that our culture, maybe even our species, would whither away. When the actual experience of virtual reality turned out to be more like trying to play Pac-Man with a bowling ball taped to your head, the talk died down. To his credit, Minsky recognizes that the merger of human and machine lies quite a few years away.
17. Mass insanity While physical health has improved in most parts of the world over the past century, mental health is getting worse. The World Health Organization estimates that 500 million people around the world suffer from a psychological disorder. By 2020, depression will likely be the second leading cause of death and lost productivity, right behind cardiovascular disease. Increasing human life spans may actually intensify the problem, because people have more years to experience the loneliness and infirmity of old age. Americans over 65 already are disproportionately likely to commit suicide. Gregory Stock, a biophysicist at the University of California at Los Angeles, believes medical science will soon allow people to live to be 200 or older. If such an extended life span becomes common, it will pose unfathomable social and psychological challenges. Perhaps 200 years of accumulated sensations will overload the human brain, leading to a new kind of insanity or fostering the spread of doomsday cults, determined to reclaim life’s endpoint. Perhaps the current trends of depression and suicide among the elderly will continue. One possible solution—promoting a certain kind of mental well-being with psychoactive drugs such as Prozac—heads into uncharted waters. Researchers have no good data on the long-term effects of taking these medicines.
A Greater Force Is Directed Against Us
18. Alien invasion At the SETI Institute in Mountain View, California, a cadre of dedicated scientists sifts through radio static in search of a telltale signal from an alien civilization. So far, nothing. Now suppose the long-sought message arrives. Not only do the aliens exist, they are about to stop by for a visit. And then . . . any science-fiction devotee can tell you what could go wrong. But the history of human exploration and exploitation suggests the most likely danger is not direct conflict. Aliens might want resources from our solar system (Earth’s oceans, perhaps, full of hydrogen for refilling a fusion-powered spacecraft) and swat us aside if we get in the way, as we might dismiss mosquitoes or beetles stirred up by the logging of a rain forest. Aliens might unwittingly import pests with a taste for human flesh, much as Dutch colonists reaching Mauritius brought cats, rats, and pigs that quickly did away with the dodo. Or aliens might accidentally upset our planet or solar system while carrying out some grandiose interstellar construction project. The late physicist Gerard O’Neill speculated that contact with extraterrestrial visitors could also be socially disastrous. “Advanced western civilization has had a destructive effect on all primitive civilizations it has come in contact with, even in those cases where every attempt was made to protect and guard the primitive civilization,” he said in a 1979 interview. “I don’t see any reason why the same thing would not happen to us.”
19. Divine intervention Judaism has the Book of Daniel; Christianity has the Book of Revelation; Islam has the coming of the Mahdi; Zoroastrianism has the countdown to the arrival of the third son of Zoroaster. The stories and their interpretations vary widely, but the underlying concept is similar: God intervenes in the world, bringing history to an end and ushering in a new moral order. Apocalyptic thinking runs at least back to Egyptian mythology and right up to Heaven’s Gate and Y2K mania. More worrisome, to the nonbelievers at least, are the doomsday cults that prefer to take holy retribution into their own hands. In 1995, members of the Aum Shinri Kyo sect unleashed sarin nerve gas in a Tokyo subway station, killing 12 people and injuring more than 5,000. Had things gone as intended, the death toll would have been hundreds of times greater. A more determined group armed with a more lethal weapon—nuclear, biological, nanotechnological even—could have done far more damage.
20. Someone wakes up and realizes it was all a dream Are we living a shadow existence that only fools us into thinking it is real? This age-old philosophical question still reverberates through cultural thought, from the writings of William S. Burrows to the cinematic mind games of The Matrix. Hut of the Institute of Advanced Studies sees an analogy to the danger of the collapse of the vacuum. Just as our empty space might not be the true, most stable form of the vacuum, what we call reality might not be the true, most stable form of existence. In the fourth century B.C., Taoist philosopher Chuang Tzu framed the question in more poetic terms. He described a vivid dream. In it, he was a butterfly who had no awareness of his existence as a person. When he awoke, he asked: “Was I before Chuang Tzu who dreamt about being a butterfly, or am I now a butterfly who dreams about being Chuang Tzu?”
You probably think about viruses only when you’re sick, but there’s a group of microbiologists who want to change that. In fact, they want you to consider the possibility that viruses may be found in space.
Now this grim prospect has started to look a little bit more likely following the revelation that killer viruses could survive out there in the endless void. Huge fight broke out between relatives at toddler’s inquest A human would last less than 20 seconds in the cold and empty vacuum of space – the time it would take to use up all the oxygen in the body.
The lack of atmosphere would cause gas bubbles to form in the blood and other fluids, blowing the person up into a balloon before they die from decompression.
But viruses are very hardy and could be living everywhere in the universe including other planets, moons and even the void of space, Nasa scientists suspect. If we find viruses on Mars, it’s a fair bet to assume other lifeforms existed there too.
Now a team of scientists are calling on space agencies to look for them in liquid samples from Saturn and Jupiter’s moons as well as rocks from Mars. If we manage to detect viruses in these samples, it could prove if they really can survive in space and allow us to identify just how much risk they pose to our species.
Biologist Prof Stedman, from Portland State University in the United States, said: ‘More than a century has passed since the discovery of the first viruses. ‘Entering the second century of virology we can finally start focusing beyond our own planet.’ If a space explorer contracted a space virus or one found its way to Earth, the results could be devastating because humanity will have no resistance to it.
In a recent review, published online Jan. 10 in the journal Astrobiology, a trio of scientists from the U.S. and Japan posited that viruses may be spread across interplanetary space. Those researchers want to convince astrobiologists to devote more time looking for these curious molecular machines.
A virion — the form a virus takes outside of a host — consists of genetic material encapsulated in a protein shell. Some viruses also have an outer lipid layer called an envelope. One way to think of a virion is as a seed or a spore, the authors wrote.
Viruses straddle the definition of life. They lack the machinery to reproduce on their own, so they must infect a host cell and hijack its machinery. This has led to decades of debate over whether viruses should technically be considered living.
But for the review authors, viruses’ reproductive methods are enough. Indeed, “when one considers the whole virus replication cycle, it comes close to NASA’s working definition of life: ‘a self-sustaining chemical system capable of Darwinian evolution,'” the review said.
Semantics aside, if scientists were to identify a virus in space — on a meteor, perhaps — very few people would claim the discovery was not evidence of life in space, the authors wrote.
So why aren’t scientists prowling the Martian surface, the lakes of Titan or the geysers of Enceladus for evidence of these tiny “life-forms”?
In part, it’s because the technology to do so is still in development, said senior review author Kenneth Stedman, a professor of biology at Portland State University. Currently, scientists are searching for chemical signatures they can use to identify viruses in the fossil record. But if they can’t find viruses in really old rocks on Earth, they won’t be able to do it in really old rocks on Mars or Titan, he said.
Viruses are not metabolically active on their own, so they produce few by-products. Lipids in the envelopes are the current front-runner for a virus biomarker, since these compounds can survive for hundreds of millions of years, Stedman told Live Science. But scientist have yet to establish that these molecules are unique to viruses, and don’t exist in any cellular organism as well.
Currently, scientists can identify viruses by looking at the structure of their shells using electron microscopes. But it isn’t possible to strap these high-powered machines onto a Mars rover, yet. And given the diversity of virus forms on Earth, Stedman said that he doubts scientists would even recognize the shape of an alien virus.
Here on Earth, viruses form a crucial part of life, Stedman said. For one, viruses are everywhere. The oceans alone contain an estimated 10^31 individual virions. That’s about 1 million times more than estimates of the number of stars in the observable universe. And viruses are integral in most of the nutrient cycles on our planet.
What’s more, viruses and cells have been coevolving basically since life arose on the planet, Stedman said. Cells evolving to resist their viral invaders give rise to new forms and behaviors. And viruses shepherd genes between unrelated cells in what scientists call horizontal gene transfer. While this process has precipitated tremendous diversity of life on Earth, it muddies the water for researchers tracking viral evolution. “If there’s any water in the mud, you’re in luck,” Stedman said.
Scientists do know that viruses use both RNA and DNA, in single- and double-stranded forms, to code their genetic information, Stedman said. All known cellular life uses double-stranded DNA, so some scientists think that viruses may be remnants of ancient life-forms that predate the development of DNA.
This is all to say that “life on Earth would be very different if there were no viruses,” Stedman said.
Scientists are currently skilled in identifying only cellular life. In addition to helping scientists learn more about our own origins, devising ways to identify viruses is good practice for recognizing other, novel forms of life we might encounter, according to Stedman. Keeping an open mind when looking for life is crucial, as many environments are quite different than Earth.
“What is life? Are viruses alive? If we find viruses [in space], is it indicative of life? And would this be life as we know it or life as we don’t know it?” Stedman asked. “We’re hoping to get people thinking about these types of definitions.”
Sagittarius A*, the supermassive black hole at the centre of the Milky Way, isn’t exactly rowdy. It’s not classified as an active galactic nucleus – one of those galactic cores that glow exceedingly brightly as they feast on copious amounts of material from the surrounding space.
However, the brightness of our galaxy’s centre does fluctuate a little across the electromagnetic spectrum on a daily basis. Astronomers have now confirmed that, over the last few years, Sgr A*’s most energetic X-ray flares have been increasing.
The paper has been accepted in the journal Astronomy & Astrophysics, and is already available on arXiv while it undergoes the peer review process. The results support the conclusions of earlier studies that have found our galactic centre is indeed getting restless.
Specifically, a team of French and Belgian researchers led by astrophysicist Enmanuelle Mossoux of the University of Liège in Belgium continued their work from a 2017 paper that found the rate of bright flares had increased threefold from 31 August 2014.
The earlier work – also co-authored by Mossoux – studied X-ray data on Sgr A* from the XMM-Newton, Chandra and Swift observatories collected between 1999 and 2015. They detected 107 flares in total. Not only were the brightest X-ray flares increasing after August 2014, the faintest ones had decreased from August 2013.
To find out if these trends have continued, Mossoux and colleagues collected and analysed the data from all three telescopes between 2016 and 2018. They detected 14 more flares to add to the previous data for a total of 121.
Then, they analysed all the flares, using the previous methods, and revised methods to determine the flare rate and distribution. These found that one of the earlier conclusions was incorrect – there was no decrease in the rate of faint flares; these remained pretty steady over the period covered by the data.
“However, this did not change our global result: a change in flaring rate is found for the brightest and most energetic flares at the same date as was found in the previous section,” the researchers wrote in their paper.
Although these studies both only refer to X-ray flaring, they’re not the only hint in recent times that something is up with Sgr A*. Last year, the black hole flared 75 times its usual brightness in near-infrared – the brightest we’ve ever observed it in those wavelengths.
The team analysing the near-infrared observations had a dataset of 133 nights from 2003; and last year, they found three nights on which Sgr A* near-infrared activity was elevated. They said in their paper that this was “unprecedented compared to the historical data.”
(Don’t worry, Sgr A* is 26,000 light-years away. The big bad black hole can’t get you.)
Mossoux and her team have also checked to see if the 2019 activity is consistent with their recent findings. They analysed the Swift data from 2019, and found four bright flares, the largest number ever observed in a single campaign, confirming that the black hole is not settling down.
Additionally, XMM Newton and Chandra data from 2019 – due for release this year – could reveal even more about the peculiar X-ray activity, and what might be causing it – whether it’s accretion, or something else, such as the tidal disruption of passing asteroids.
Observations across other wavelengths could reveal more information too. Continued observations in the near-infrared, and radio wave observations, could help us figure out what’s making Sgr A* stir.
The lander will continue its low-frequency radio astronomy observations, but a new plan has been formulated for the Yutu 2 rover, which has already provided insights into the composition of the surface and what lies below.
Li Chunlai, deputy director of the National Astronomical Observatories of China (NAOC), told the state-run news outlet CCTV+ that the Yutu 2 team are targeting distant areas.
Yutu 2 has been driving across an area covered in ejecta from impact craters, but reaching new ground would be insightful.
“If it can enter a basalt zone, maybe we can better understand [the] distribution and structure of ejecta from meteorite impacts,” Li said. “The distance may be 1.8 kilometers [1.1 miles]. I think it may take another one year for the rover to walk out of the ejecta-covered area.”
The resilient rover, which has far exceeded its design life time of three months, or three lunar days, would need to greatly boost its average drive distances to reach the area, however.
Yutu 2 has averaged 88 feet (26.7 meters) per lunar day for the 15 days so far, it would need to start covering around 492 feet (150 m) per day.
Even if Yutu 2 does not reach this area, the rover will further contribute to our understanding of the lunar surface and subsurface with its science payloads, Ian Crawford, professor of planetary science and astrobiology at Birkbeck College, University of London, told Space.com in an email.
He adds however that the “extreme slowness of these small rovers is a strong argument for a human return to the moon.”
“The Apollo 17 astronauts traversed about 35 kilometers (22 miles) in three days, which was actually only about 22 hours of Extra Vehicular Activity time,” Crawford notes.
China is planning a lunar sample return mission, Chang’e 5, for later this year. Subsequent missions are expected to target the lunar south pole before potential crewed missions in the 2030s.
NASA meantime is developing its Artemis program to return astronauts to the moon by 2024 to 2028.
For years, amateur astronomers have been waiting for a bright, naked-eye comet to pass by Earth — and finally, such an object may have arrived.
The possible celestial showpiece is known as Comet ATLAS, or C/2019 Y4. When it was discovered on Dec. 28, 2019, it was quite faint, but since then, it has been brightening so rapidly that astronomers have high hopes for the spectacle it could put on. But given the tricky nature of comets, skywatchers are also being cautious not to get their hopes up, knowing that the comet may fizzle out.ADVERTISING
It’s been awhile since a comet gave skywatchers a good show, particularly in the Northern Hemisphere. In March 2013, Comet PanSTARRS was visible right after sunset, albeit low in the western sky. But although it briefly attained first magnitude with a short, bright tail, its low altitude and a bright, twilight sky detracted from what otherwise would have been a much more prominent object. Comet Lovejoy in 2011 and Comet McNaught in 2007 both evolved into stunning objects, but unfortunately, when at their best, were visible only from the Southern Hemisphere.
It has now been nearly a quarter of a century since we have been treated to a spectacularly bright comet: Comet Hale-Bopp passed by during the spring of 1997 and Comet Hyakutake did so exactly one year earlier. Both were truly “great” comets, very bright and fantastically structured; in very dark conditions, Hyakutake’s tail appeared to stretch more than halfway across the sky.
So now, after a “comet drought,” Comet ATLAS may finally enliven the evening skies of early spring. Or then again, maybe not.
When astronomers first spotted Comet ATLAS in December, it was in Ursa Major and was an exceedingly faint object, close to 20th magnitude. That’s about 398,000 times dimmer than stars that are on the threshold of naked-eye visibility. At the time, it was 273 million miles (439 million kilometers) from the sun.
But comets typically brighten as they approach the sun, and at its closest, on May 31, Comet ATLAS will be just 23.5 million miles (37.8 million km) from the sun. Such a prodigious change in solar distance would typically cause a comet to increase in luminosity by almost 11 magnitudes, enough to make ATLAS easily visible in a small telescope or a pair of good binoculars, although quite frankly nothing really to write home about.
Except, since its discovery, the comet has been brightening at an almost unprecedented speed. As of March 17, ATLAS was already magnitude +8.5, over 600 times brighter than forecast. As a result, great expectations are buzzing for this icy lump of cosmic detritus, with hopes it could become a stupendously bright object by the end of May.
A famous lineage
Another factor buoying hopes for ATLAS as a potential dazzler is that its orbit is nearly identical to that of the so-called Great Comet of 1844.
Like the 1844 comet, ATLAS follows a trajectory that would require 6,000 years per orbit and take it to beyond the outer reaches of the solar system, roughly 57 billion miles (92 billion km) from the sun. Probably in the far-distant past, a much larger comet occupied this same orbit, but fragmented into several pieces — including the 1844 comet and ATLAS — upon rounding the sun.
But any comparison is dangerous. The 1844 comet was not discovered until shortly after perihelion, so we have no knowledge of its brightness behavior beforehand. But that information is currently all we know about ATLAS, and we won’t be able to see the object after it reaches the sun.
And let’s not forget some of the comets of the past that seemingly had “glory” written all over them, only to utterly fail to live up to expectations: Comet ISON in 2013, Comet Austin in 1990 and Comet Kohoutek in 1974.
So what’s ahead?
John Bortle, who has observed hundreds of comets and is a well-known expert in the field, got his first look at Comet ATLAS through 15 x 70 binoculars on Sunday night (March 15). And he’s stumped, he wrote. “For the first time in many years I am left at a bit of a loss as to what honestly worthy advice I can offer would-be observers. I really don’t know quite what to make of this object.”
The head (or coma) of Comet ATLAS is big, albeit “very faint and ghostly,” Bortle said, which doesn’t make sense. “If it’s a truly significant visitor, it should be considerably sharper in appearance. Instead we see, at best, a quite modestly condensed object with only a pinpoint stellar feature near its heart.”
The unpredictability of comets is an old story. Astronomers use special formulas to try to anticipate how bright a comet will get. Unfortunately, comets’ individual behavior and characteristics can be as varied as people: No two are alike.
Now, here is the conundrum regarding Comet ATLAS: Until a couple of weeks ago, it was brightening at an astounding rate. That brightening has slowed somewhat, but it is still an impossible rate of brightening to maintain. Were ATLAS to continue to brighten at this rate all the way to its closest approach to the sun at the end of May, it would end up rivaling the planet Venus in brightness!
“We should expect the rate of increase to slow again,” Carl Hergenrother, an assiduous comet observer based in Arizona, said. “This is where it gets tricky for predicting just how bright it will get.” Right now, no one can predict how long it will continue to quickly brighten and how dramatically that brightening will slow.
Where to look and what to expect
The only thing left to do is to track Comet ATLAS in the days and weeks ahead. Fortunately, its path in March and April will be very favorable for Northern Hemisphere observers, as it will be circumpolar and always remain above the horizon. As darkness falls, it will be positioned more than halfway up in the north-northwest sky. Right now, the comet is in western Ursa Major, and it will shift into the boundaries of Camelopardalis the Giraffe — a rather dim, shapeless star pattern — by March 29. There it will stay, right on through the month of April.Advertisement
As to how bright Comet ATLAS will get, that’s anybody’s guess. It might become faintly visible to the naked eye under dark sky conditions by mid- or late April. By mid-May, when it disappears into the bright evening twilight, perhaps it will have brightened to second magnitude — about as bright as Polaris, the North Star.
Whether ATLAS continues to overperform and shines even brighter, develops a significant tail or suddenly stops brightening altogether and remains very faint and ghostly are all unknown right now. We’ll just have to wait and see.
“It’s going to be fun the next few weeks watching Comet ATLAS develop (and provide a nice distraction from the current state of the world), Hergenrother wrote. “Here’s to good health and clear skies!”
A cannonball that a Japanese spacecraft fired at an asteroid is shedding light on the most common type of asteroid in the solar system, a new study reports.
Carbonaceous, or C-type, space rocks make up about three-quarters of known asteroids. Previous research suggests that they are relics of the early solar system that contain troves of primordial material from the nebula that gave birth to the sun and its planets about 4.6 billion years ago. This makes research into these carbon-rich asteroids essential to understanding planetary formation.
In 2018, Hayabusa2 arrived at Ryugu to scan it from orbit and deploy multiple rovers on the boulder-covered asteroid. Scientists found that Ryugu is likely a loosely packed, very porous pile of rubble, about 50% empty space.
To shed light on Ryugu’s composition and structure, Hayabusu2 shot a 4.4-lb. (2 kilograms) copper cannonball a bit larger than a tennis ball at about 4,475 mph (7,200 km/h) at the asteroid. The impact carved out an artificial crater that exposed pristine material under Ryugu’s surface for remote analysis and blasted out a plume of ejected material. Hayabusa2’s cameras recorded the evolution of this plume in detail.
The number and size of craters that pockmark asteroids such as Ryugu can help scientists estimate the age and properties of asteroid surfaces. These analyses are based on models of how such craters form, and data from artificial impacts like that on Ryugu can help test those models.
The cannonball, dubbed the Small Carry-on Impactor (SCI), blasted out a crater about 47.5 feet (14.5 m) wide with an elevated rim and a central conical pit about 10 feet (3 m) wide and 2 feet (0.6 m) deep.
“I was so surprised that the SCI crater was so large,” study lead author Masahiko Arakawa, a planetary scientist at Kobe University in Japan, told Space.com. The crater was about seven times larger than what might be expected from a comparable scenario on Earth, he added.
The artificial crater was semicircular in shape, and the curtain of ejected material was asymmetrical. Both of these details suggest that there was a large boulder buried near the impact site, the researchers said. This conclusion matches the rubble-pile picture that scientists already had of Ryugu.Click here for more Space.com videos…Watch Asteroid Debris Fly During Japan’s Hayabusa2’s 2nd TouchdownVolume 0% PLAY SOUND
Features of the artificial crater and the plume suggested that the growth of a crater was limited mostly by the asteroid’s gravity and not by the strength of the space rock’s surface. This, in turn, suggested that Ryugu has a relatively weak surface, one only about as strong as loose sand, which is consistent with recent findings that Ryugu is made of porous, fragile material.
These new findings suggest that Ryugu’s surface is about 8.9 million years old, while other models suggested that the asteroid’s surface might be up to about 158 million years old. All in all, while Ryugu is made of materials up to 4.6 billion years old, the asteroid might have coalesced from the remains of other broken-apart asteroids only about 10 million years ago, Arakawa said.
The scientists detailed their findings online Thursday (March 19) in the journal Science.
The asteroid Ryugu has a texture that is highly porous, new images from a Japanese space reveal.
“It is something like freeze-[dried] coffee,” planetary scientist Tatsuaki Okada of the Japanese Aerospace Exploration Agency explained to Science News.
Ryugu’s heat map shows that it’s about 50 percent porous, meaning half of it is holes, Okada and colleagues report. Even most of the asteroid’s large boulders appear porous.
The Hayabusa2 spacecraft measured the maximum temperatures during one full rotation of the asteroid Ryugu and found that most of the asteroid stays cool. (T. Okada et al/Nature 2020 ) (T. Okada et al/Nature 2020)
Science News reports the airiness of the rock’s texture fits with the idea that Ryugu is essentially a chunk of rubble created from the breakup of a larger mass about 700 million years ago.
“This might be common for the asteroids and even for planetesimals in the early solar system,” Okada says.
The researchers reported their observations Monday in the journal Nature.
While the scorching planet Mercury might not be the first place you’d think to look for ice, the MESSENGER mission confirmed in 2012 that the planet closest to the Sun does indeed hold water ice in the permanently-shadowed craters around its poles. But now a new study regarding Mercury’s ice provides even more counter-intuitive details about how this ice is formed. Scientists say heat likely helps create some of the ice.
Brant Jones, a researcher in Georgia Tech’s School of Chemistry and Biochemistry and the study’s first author, said this isn’t some strange, crazy idea. While it’s a bit complicated, it’s mostly just basic chemistry.
The planet’s extreme daytime heat combined with the super-cold (minus 200-degree Celsius) temperatures in the permanently shadowed craters might be acting like an “ice-making chemistry lab.”
“There is a surprising amount of ice on Mercury and significantly more than on the Moon,” Brant told Universe Today.
The process for creating ice on Mercury is similar to what happens on the Moon. Back in 2009, scientists determined electrically charged particles from the Sun’s solar wind were interacting with the oxygen present in some dust grains on the lunar surface to produce hydroxyl. Hydroxyl (OH) is just one atom of hydrogen with an oxygen atom, instead of the two hydrogen atoms found in water.
Brant worked with other scientists, including colleague Thomas Orlando, also from Georgia Tech, to refine the understanding of that process. In 2018, they published a paper that showed that while this process on the Moon produced significant amounts of hydroxyls, it produced very little molecular water.
“Though the solar wind was suggested as a potential source term in the 2009 observations of water on the Moon,” Orlando said via email, “the mechanisms were never really identified. We modeled this for the Moon but the importance was not as significant on the Moon due to the overall much lower temperatures.”
But they knew this process could also take place on asteroids, Mercury or any other surface that is bombarded by the solar wind.
“In order to create molecular water, you need one more ingredient, and that is heat,” said Brant.
Daytime temperatures on Mercury can reach 400 degrees Celsius, or 750 degrees Fahrenheit.
Minerals in Mercury’s surface soil contain what are called hydroxyl groups. The extreme heat from the Sun helps to free up these hydroxyl groups then energizes them to smash into each other to produce water molecules and hydrogen that lift off from the surface and drift around the planet.
Some water molecules are broken down by sunlight and dissipate. But other molecules land near Mercury’s poles in deep, dark craters that are shielded from the Sun. The molecules get trapped there and become a part of the growing, permanent glacial ice housed in the shadows.
“It’s a little like the song Hotel California. The water molecules can check in to the shadows but they can never leave,” said Orlando in a press release.
“The total amount that we postulate that would become ice is 1013 kilograms (10,000,000,000,000 kg or 11,023,110,000 tons) over a period of about 3 million years,” Jones said. “The process could easily account for up to 10 percent of Mercury’s total ice.”
The data used for their study comes from the MESSENGER spacecraft, which orbited Mercury between 2011 and 2015, studying the planet’s chemical composition, geology, and magnetic field. MESSENGER’s findings of polar ice corroborated previous signatures for ice picked up years earlier by Earth-based radar.
Mariner 10 was the first spacecraft sent to the planet Mercury; the first mission to explore two planets during a single mission; the first to use a gravity assist to change its flight path; the first to return to its target after an initial encounter; and the first to use the solar wind as a major means of spacecraft orientation during flight. But what did it capture with its two onboard cameras?
During its flyby of Venus, Mariner 10 discovered evidence of rotating clouds and a very weak magnetic field. Using a near-ultraviolet filter, it photographed Venus’s chevron clouds and performed other atmospheric studies.
The spacecraft flew past Mercury three times. Owing to the geometry of its orbit – its orbital period was almost exactly twice Mercury’s – the same side of Mercury was sunlit each time, so it was only able to map 40–45% of Mercury’s surface, taking over 2,800 photos. It revealed a more or less Moon-like surface. It thus contributed enormously to our understanding of Mercury, whose surface had not been successfully resolved through telescopic observation. The regions mapped included most or all of the Shakespeare, Beethoven, Kuiper, Michelangelo, Tolstoj, and Discovery quadrangles, half of Bach and Victoria quadrangles, and small portions of Solitudo Persephones (later Neruda), Liguria (later Raditladi), and Borealis quadrangles.
Mariner 10 also discovered that Mercury has a tenuous atmosphere consisting primarily of helium, as well as a magnetic field and a large iron-rich core. Its radiometer readings suggested that Mercury has a night time temperature of −183 °C (−297 °F) and maximum daytime temperatures of 187 °C (369 °F).
Planning for MESSENGER, a spacecraft that surveyed Mercury until 2015, relied extensively on data and information collected by Mariner 10.
On February 6, 2018, at 2045 UTC, the first Falcon Heavy was launched into space. It contained a very special payload- a Tesla Roadster with Starman.
But where is this vehicle? The current location is 203,837,502 miles (328,044,762 km, 2.193 AU, 18.24 light minutes) from Earth, moving toward Earth at a speed of 18,756 mi/h (30,184 km/h, 8.38 km/s).
The car is 90,671,738 miles (145,922,063 km, 0.975 AU, 8.11 light minutes) from Mars, moving toward the planet at a speed of 9,603 mi/h (15,454 km/h, 4.29 km/s).
The car is 149,430,277 miles (240,484,795 km, 1.608 AU, 13.37 light minutes) light minutes from the Sun, moving away from the star at a speed of 6,842 mi/h (11,011 km/h, 3.06 km/s).
The car has exceeded its 36,000 mile warranty 29,614.4 times while driving around the Sun, (1,066,119,513 miles, 1,715,753,572 km, 11.47 AU) moving at a speed of 46,644 mi/h (75,066 km/h, 20.85 km/s). The orbital period is about 557 days.
It has achieved a fuel economy of 8,461.3 miles per gallon (3,597.3 km/liter, 0.02780 liters/100 km), assuming 126,000 gallons of fuel.
If the battery was still working, Starman has listened to Space Oddity208,809 times since he launched in one ear, and to Is there Life On Mars?281,362 times in his other ear.
Starman has completed about 1.380 orbits around the Sun since launch.
A telescope about 48,145 ft (14,675 m) in diameter would be required to resolve the Upper stage from Earth. A smaller one could see him as an unresolved dot, about 92.6 ft (28.2 m) in diameter, in ideal conditions.
The vehicle has traveled far enough to drive all of the world’s roads 47.2 times.
It has been 2 years, 1 month, 9 days, 8 hours, 49 minutes and 33 seconds since launch.
We’re used to thinking of possible homes for life on watery worlds orbiting stars like the sun, but a new research paper has found a new potential habitat: a rocky planet orbiting just past the event horizon of a rapidly spinning supermassive black hole.
The exotic forces around that black hole are able to warm up the planet just right, but the scenario comes with a catch: the planet must orbit at nearly the speed of light.
Habitat for humanity
We don’t know all the possible places that life could arise in our universe, because so far we only have one example: us. And while scientists (and sci-fi authors) enjoy thinking about all sorts of exotic arrangements and possibilities for lifeforms, for serious searches of extraterrestrial intelligence, our best bet is to use our own circumstances as a template, hunting for life that isn’t too dissimilar to what we find on Earth.
From that, we can draw two extremely broad requirements. One, life like our own requires liquid water. Water is the most common molecule in the universe, composed of hydrogen (element No. 1 when it comes to abundance in the cosmos) and oxygen (the byproduct of fusion reactions inside stars like our sun, making it also very common). But that water is usually either vaporized into a plasma (and hence very bad for life) or locked down in its solid, frozen state as ice (also not very good for life).
The liquid stuff is harder to come by, and requires a source of heat that isn’t so hot that water just evaporates. We’ve found this perfect balance in only two kinds of locations: the so-called “habitable zone” of stars, a band of orbits where the light output it just right; and buried underneath the icy crusts of certain moons of the outer planets in our solar system, where tidal heating generates the necessary energy.
But just raw heat isn’t enough. Life is a complex process that uses energy to do interesting things (like move around, eat and reproduce). All those processes are not perfectly efficient, so they generate waste heat. This waste heat must be dumped safely away from the environment; otherwise, you end up with nightmare greenhouse scenarios, with temperatures escalating to uncontrolled levels and killing off any life that got started.
On the Earth, we dump our waste heat into the vacuum of space itself in the form of infrared radiation. This contrast, between a source of energy and a place to put all the waste, enables life to flourish on our home planet, and presumably any other planet with a similar setup.
At first glance, black holes appear to be the least inviting homes for any potential lifeforms. After all, they are objects made of pure gravity, pulling in anything that gets too close beneath their event horizons, shutting them off from further contact with the rest of the universe forever. Nothing, not even light, can escape their gravitational maw.
Black holes don’t give off light themselves — they’re black, after all — but that inescapable gravity can provide a surprise, unique to them throughout the cosmos.
Permeating the universe is something called the cosmic microwave background (CMB). The CMB is the leftover radiation from when the universe was just a baby, only 380,000 years old. It is, by far, the greatest source of radiation in the entire cosmos, easily swamping all the stars and galaxies by many orders of magnitude. The reason you don’t see it is that it’s primarily in the microwave region of the electromagnetic spectrum (hence the name).
In other words, the CMB is cold, with a temperature just about 3 degrees above absolute zero.
But as that CMB light falls into a black hole, it becomes blueshifted, bumped to higher and higher energies from the extreme gravity. Just before it hits the event horizon, CMB light can gain so much energy that it shifts into infrared, visible and even ultraviolet portions of the spectrum.
In other words, near a black hole, the CMB stops being cold, and gets very, very hot.
What’s more, if the black hole is spinning, it’s able to focus the light into a narrow beam, making the CMB appear as a single spot on the sky. Kind of like a sun.Click here for more Space.com videos…Search for Alien Life – Decades of Earth Observations a KeyVolume 0% PLAY SOUND
So if you’re able to get close enough to a black hole, you’ll find yourself surprisingly warm, and if you’re a planet, you might just find your water ice converted into liquid water oceans — a potential home for life.
But for life to thrive, it also needs a heat sink, which can handily be provided by the black hole itself. Close to the black hole, gravitational distortions enlarge the appearance of the event horizon, swelling it far larger than you might naively think.
Close enough to the black hole (say, at a radius less than 1% above the event horizon), the hot CMB shrinks to fill only a small disk, while the event horizon swells to cover 40% of the sky. If your planet is rotating, you then have a “sun” and a “night” — and life has everything it needs to do its business.
But orbits at this radius are usually extremely unstable, prone to just falling all the way into the terrible blackness itself. Recently, a team of researchers published an analysis in The Astrophysical Journal, exploring this scenario to see if there was any way to stabilize the situation.
And they found a way to make it work. If the black hole is big, at least 1.6×108 times the mass of the sun, and rapidly spinning, then it hosts a “habitable zone” just barely above the event horizon, where the CMB light peaks in the UV part of the spectrum — hot, but not terrible. Any closer and the planet would be destroyed by extreme gravitational forces, and any farther and the CMB would be too cold. But in that narrow band? Just right.
Though this scenario is possible, it wouldn’t be very pretty. The planet would have to orbit at nearly the speed of light, experiencing a time dilation factor of thousands — meaning that for every second that goes by on that world, hours would slide by for us. And who knows if a planet could even find its way that close to a black hole while still surviving.
Still, the work shows that we have to keep our minds open when it comes to potential homes for life, up to and including some of the most terrible environments in the universe.
Astronomers are getting closer to discovering the elusive and mysterious Planet Nine after 139 “minor planets” were discovered past Neptune’s orbit.
These objects, ones “that were not previously published,” are not officially planets or comets, but rather space objects that orbit the Sun. In total, the discovery is five percent of the trans-Neptunian object (TNO) population, bringing the number to approximately 3,000, according to a statement accompanying the study.
“Pluto, the best-known TNO, is 40 times farther away from the sun than Earth is, and the TNOs found using the [Dark Energy Survey] data range from 30 to 90 times Earth’s distance from the sun,” the statement reads. “Some of these objects are on extremely long-distance orbits that will carry them far beyond Pluto.”
Artist’s illustration of Planet Nine, a hypothetical world that some scientists think lurks undiscovered in the far outer solar system. (R. Hurt (IPAC)/Caltech)
The researchers used data from the DES between 2013 and 2017, which uses a 520-megapixel Dark Energy Camera. It is on the Blanco 4-meter telescope at the Cerro Tololo Inter-American Observatory in Chile.
There were 7 billion DES-detected dots that the researchers started with, a list that was condensed to 22 million “transient” objects and then eventually, approximately 400 objects that were observed over six separate nights.
“We have this list of candidates, and then we have to make sure that our candidates are actually real things,” the study’s lead author, Pedro Bernardinelli, said in the statement.
The objects range between 30 and 90 astronomical units from the sun. One astronomical unit is the equivalent of 93 million miles or the distance between the Earth and the sun.
“Dedicated TNO surveys have a way of seeing the object move, and it’s easy to track them down,” Bernardinelli added. “One of the key things we did in this paper was figure out a way to recover those movements.”
It’s expected that the discovery could play a role in further searches for TNOs, notably the infamous Planet 9.
“There are lots of ideas about giant planets that used to be in the solar system and aren’t there anymore, or planets that are far away and massive but too faint for us to have noticed yet,” the study’s co-author Gary Bernstein said. “Making the catalog is the fun discovery part. Then, when you create this resource, you can compare what you did find to what somebody’s theory said you should find.”
A hypothetical planet that has been described as “the solar system’s missing link,” Planet 9 (also known as Planet X) has been part of the lexicon for several years, first mentioned in 2014. It was brought up again in 2016, when Caltech astrophysicists Mike Brown and Konstantin Batygin first wrote about it.
In October 2017, Batygin said that there are “five different lines of observational evidence” that point to the existence of Planet Nine.
The five lines of evidence are:
Six known objects in the Kuiper Belt, all of which have elliptical orbits that point in the same direction.
The orbits of the objects are all tilted the same way; 30 degrees “downward.”
Computer simulations that show there are more objects “tilted with respect to the solar plane.”
Planet Nine could be responsible for the tilt of the planets in our solar system; the plane of the planet’s orbit is tilted about 6 degrees compared to the Sun’s equator.
Some objects from the Kuiper Belt orbit in the opposite direction from everything else in the solar system.
“No other model can explain the weirdness of these high-inclination orbits,” Batygin said at the time. “It turns out that Planet Nine provides a natural avenue for their generation. These things have been twisted out of the solar system plane with help from Planet 9 and then scattered inward by Neptune.”
In October 2017, NASA released a statement saying that Planet 9 might be 20 times further from the Sun than Neptune is, going so far as to say “it is now harder to imagine our solar system without a Planet 9 than with one.”
Some researchers have suggested the mysterious planet may be hiding behind Neptune and it may take up to 1,000 years before it’s actually found.
Two studies published in March 2019 offered support of its existence, however, a separate study published in September 2019 suggested the theoretical object may not be a giant planet hiding behind Neptune — but rather a primordial black hole.
A study published in January 2019 suggested that some of the farthest celestial bodies in our planetary system aren’t being impacted by this yet-to-be-discovered planet, but rather another mysterious object deep in the echoes of space.
65 million years ago, a large asteroid collided with Earth near present-day Chicxulub, Mexico. The impact was a climactic event that likely contributed to dinosaur extinction. Today, Earth remains vulnerable to asteroid collisions.
In recent history, space rocks have landed in The United States, Russia, and elsewhere. In the event of a potential asteroid collision, NASA has developed several options for dealing with the threat. Researchers at NASA’s Center for Near Earth Object Studies and Jet Propulsion Laboratory have proposed using blunt force, weaponized deflection or a theoretical tool called a gravity tractor to deflect impact. In addition to developing contingency plans, NASA scientists are also searching the sky for future asteroid threats.
Although an asteroid of that size would be rare — NASA estimates a one-mile-wide asteroid only hits the Earth once every one million years — the two agencies have performed multiple test runs to ensure we’d be prepared.
“It’s not a matter of if, but when, we will deal with such a situation,” said astrophysicist Thomas Zurbuchen.
Astronomers suggest microbes might hitch lifts on interstellar asteroids.
Could the Earth be a life-exporting planet? That’s the curious question examined in a recent paper written by Harvard University astronomers Amir Siraj and Abraham Loeb.
The researchers take a novel twist on the controversial notion of panspermia – the idea, propelled into the mainstream in the early 1970s by astronomers Fred Hoyle and Chandra Wickramasinghe, that life might have started on Earth through microbes arriving from space.
The theory is generally discounted, although eminent astrophysicists such as Stephen Hawking conceded it was at least possible, and a major paper published in 2018 revived the topic big-time.
In their paper, Siraj and Loeb reverse the standard assumption about the direction of the microbial journey and ask whether it is possible to that at some point Earth-evolved bacteria could have been propelled away from the planet, possibly to be deposited somewhere else in the Milky Way.
To examine the idea, they fed several bits of evidence, and a few reasonable assumptions, into a computer and let the numbers run.
First and foremost, they rely on evidence from several studies that confirm the existence of airborne microbial colonies as high as 77 kilometres above the surface of the planet. The authors note that “the abundance of microbes in the upper atmosphere is poorly constrained”, so the density of life in the upper reaches remains largely guesswork.
Also unknown at this point is whether bacteria colonies persist above 100 kilometres up.
In the absence of any extraterrestrial versions of dirt-sampling spacecraft such as Japan’s Hayabusa asteroid-lander, the only viable transport methods for shipping microbes out of Earth’s atmosphere, the researchers say, are long-period comets and interstellar objects.
The comets, they note, “can easily be ejected from the Solar System by gravitational interactions with planets due to their low gravitational binding energies and planet-crossing orbits”. Interstellar objects are new to the scenario, their existence well demonstrated by the recent discoveries of ‘Oumuamua and 2I/Borisov – both high-speed big lumps of rock that entered the solar system from elsewhere.
At particular speeds and particular angles, they calculate, both comets and asteroids could come close enough to Earth to “graze” its upper atmosphere before being flung out of the Solar System with the aid of a gravitational slingshot generated by the close encounter.
During such an interaction, the objects would inevitably plough through the airborne bacterial colonies – the researchers cite Bacillus subtilis, Deinococcus radiodurans, Escheria coli, and Paracoccus denitrificans as the most likely candidates.
Sufficient numbers of the newly gathered passengers, the modelling shows, would survive the g-forces of the slingshot acceleration and the friction-induced heating caused by leaving the atmosphere.
Siraj and Loeb calculate that across the life of Earth, between one and 10 comets and between one and 50 interstellar objects have come close enough to graze the atmosphere.
Previous research has shown that bacteria could easily survive on board an asteroid or comet in interstellar space – lapsing into suspended animation if necessary – and could just as easily survive the enormous pressure caused by their transport smacking into a planet.
Thus, the researchers conclude that although much more research is needed – particularly into the make-up and distribution of microbes in the upper atmosphere – the idea of panspermia beginning on this planet and heading outwards is “realistic”.
The truth of the matter might never be known, of course, at least for several centuries; but it is at least possible that somewhere many light years hence there is a corner of a distant solar system that is forever Earth.
It’s lonely out there in deep space. Especially when a spacecraft has travelled so far into the vast emptiness, interstellar space is now all it can truly call home.
Of course, this was always Voyager 2’s fate. The spacecraft – which launched over 40 years ago and now stands as NASA’s longest-running space mission – was designed to venture out to the boundaries of our Solar System. For decades, it’s done just that, but the incredible voyage is about to encounter a challenge it hasn’t faced in all that long, lonesome journeying.
NASA has announced that Deep Space Station 43 (DSS–43) – the only antenna on Earth that can send commands to the Voyager 2 spacecraft – is going silent, and not for a short time.
The giant dish, located in Australia, and roughly the size of a 20-storey office building, requires critical upgrades, the space agency says. The Canberra facility has been in service for almost 50 years, so it’s not surprising that the ageing hardware needs maintenance.
Nonetheless, the work comes at a cost. For approximately 11 months – until the end of January 2021, when the repairs are expected to be complete – Voyager 2 will be totally alone, coasting into the unknown in a quiescent mode of operation designed to conserve power and keep the probe on course until DSS–43 comes back online.
“We put the spacecraft back into a state where it will be just fine, assuming that everything goes normally with it during the time that the antenna is down,” explains Voyager project manager Suzanne Dodd from NASA’s Jet Propulsion Laboratory.
“If things don’t go normally – which is always a possibility, especially with an ageing spacecraft – then the onboard fault protection that’s there can handle the situation.”
During this almost year-long period of radio silence, the silence will only be one-way. Other antennas in the Canberra Deep Space Communication Complex (CDSCC) will be configured to receive any signals Voyager 2 broadcasts to Earth; it’s just that we won’t be able to say anything back, even if we need to.
Artist’s concept of Voyager 2. (NASA/JPL-Caltech)
While NASA has done everything it can to prepare Voyager 2 for the communications blackout, it’s still a gamble – a calculated one, sure, but also seemingly an unprecedented predicament in the long duration of this historic space mission.
“There is risk in this business as there is in anything in spaceflight,” CDSCC education and public outreach manager Glen Nagle told The New York Times. “It’s a major change and the longest downtime for the dish in the eighteen years I’ve been here.”
According to the space agency, the biggest unknowns are whether Voyager 2’s automated thrust control systems – which fire several times a day to keep the probe’s antenna oriented towards Earth – will work accurately for such an extended period, and whether power systems designed to keep Voyager 2’s fuel lines sufficiently heated will also do their job.
The new challenge comes only days after NASA confirmed the spacecraft had resumed normal operations following a scare in January, when an anomaly triggered Voyager’s autonomous fault protection routines.
The malfunction meant the spacecraft failed to perform a scheduled flight manoeuvre on January 25. Painstaking assessments from NASA engineers on Earth ultimately fixed the issue, with controllers having to wait 34 hours for each single response from Voyager 2, given the 17-hour transmission time for signals to travel to and from the distant probe.
Rectifying the problem involved turning five key scientific instruments off and turning them back on again – something that reportedly had never been done before – but luckily the reboot worked a charm.
Here’s hoping the next 11 months proves equally successful for the far-flung Voyager 2, currently located over 17 billion kilometres (roughly 11 billion miles) from Earth, and scientifically confirmed to have now entered interstellar space, much like its twin before it, Voyager 1 (the only other human-made object to have travelled so far).
When DSS–43 upgrades are complete, the repairs will not only bolster our communications with Voyager 2 but will future-proof the facility for other upcoming missions, including future Mars missions.
Before that, though, perhaps the most pressing matter will be to reconnect ties with this famous pioneer from decades ago, as it sails ever further away, on its one-way trip to the stars.
In December 2017 and March 2018, The New York Times released three allegedly declassified videos showing U.S. Navy pilots trailing some unidentified flying objects. The mystery crafts moved at hypersonic speeds, flying tens of thousands of feet above the Earth with no distinct wings, engines or visible signs of propulsion whatsoever. Were they flying saucers? Incredibly high-tech drones? The pilots had no idea — and, according to a recent statement from Navy intelligence officials, neither does the U.S. government.
In a statement delivered to the intelligence news website The Black Vault, Joseph Gradisher, a spokesperson for the Deputy Chief of Naval Operations for Information Warfare, announced that the Navy officially considers the craft in these three videos “unidentified aerial phenomena.” That means that the eerie videos are authentic — and that the objects, which were detected in restricted military training airspaces in 2004 and 2015, were not supposed to be there. The objects still have not been successfully identified as any known type of aircraft.
The UFO footage was also never cleared for public release, Gradisher told The Black Vault — meaning these are three unidentified phenomena you were never supposed to know about.
According to The Black Vault, the videos may have been improperly released by a former Pentagon employee who had applied for permission to share them across several government agencies as part of a database on unmanned aerial vehicles (UAV) he was allegedly compiling. The man received permission to share the videos for “[US Government] Use Only,” paperwork obtained by The Black Vault shows. However, Navy officials never declassified the footage for public release, Gradisher said.
What was the Navy trying to withhold, specifically? Only some very bizarre aerial acrobatics. In one incident filmed in 2004, for example, the unidentified objects “appeared suddenly at 80,000 feet, and then hurtled toward the sea, eventually stopping at 20,000 feet and hovering,” The New York Times wrote. “Then they either dropped out of radar range or shot straight back up.”
To be clear, nobody is saying that these mystery aircraft have anything to do with alien visitors; they simply can’t be identified or explained by current aeronautical knowledge. Comforted? Good — because this sort of thing probably happens way more often than we know.
A longer list of Earth-like planets, eavesdropping on radio waves and looking for laser light shows: All raise the chances of detecting E.T.
Estimating the chance of getting a message from life beyond Earth, say within the next decade, isn’t easy. Even the best experts are reluctant to offer precise odds.
“Anybody who gave you a figure would be talking about religion, not science,” says Jill Tarter, the astronomer who has spent most of her life pursuing the quest to find signals from alien life.
And even if you did get an estimate for that probability, it wouldn’t mean much. (After all, the San Francisco 49ers had a 95 percent chance of winning the Super Bowl with under 8 minutes to go in the game — and still lost.)
But however small the probability of seeing a signal from E.T. is, those chances are soon going to be a lot better than they have been in the past.
Sure, after decades of listening, there is still no message. But with more data to sift through, and new technologies with superior search capabilities, odds of hearing from E.T. are rapidly improving. If the probability in the decade 2011–2021 were x percent, it’s going to be 1,000 times x in the following decade, says Andrew Siemion, director of the Berkeley SETI Research Center. (SETI stands for Search for Extra-Terrestrial Intelligence.)
The reason for E.T. optimism stems largely from several new projects in the works, enhanced with advanced methods for discerning an actual message hidden in the static of cosmic cacophony.
Siemion, speaking in Seattle on February 15 at the annual meeting of the American Association for the Advancement of Science, reported a new release of data from Breakthrough Listen, a major enterprise for recording radio signals from space. Now available for others to analyze, the data dump contains 2 petabytes of information (to store that much, you’d need 2,000 of today’s typical PCs with their puny 1 terabyte hard drives).
Tarter, chair emeritus for SETI Research at the pioneering SETI Institute, described new search projects in the works at the institute, including Laser SETI. It’s a plan to train 96 cameras at a dozen locations around the world to keep a constant vigil for “intelligent” optical signals from space.
Another key driver of increased optimism is the abundance of places to look for life. Thanks largely to the Kepler space telescope’s successful explorations, astronomers now know of thousands of stars possessing planets — and have spotted dozens of rocky, Earth-like planets orbiting their stars at a distance likely to be temperate enough for liquid water, a hopeful indicator of habitability.
And of course, it is still possible that alien life might be hiding closer to home. While it’s very unlikely that any intelligent life abides in our solar system, microbial biology might be viable on moons such as Enceladus (Saturn) and Europa (Jupiter). Robots equipped with tools to extract microorganisms from alien soil and conduct chemical analysis could search for life on site. In the meantime, land- or space-based telescopes might detect signs of biological activity in the atmosphere of distant planets. Certain combinations of molecules in the right ratio would be surefire signatures of life in action.
“The ultimate breakthrough in exoplanetary science will be the detection of a biosignature in the atmosphere of a rocky habitable-zone exoplanet,” astronomer Nikku Madhusudhan noted last year in the Annual Review of Astronomy and Astrophysics. “Defining a unique biosignature remains a theoretical challenge, but several candidate molecules have been suggested.”
No one molecule (not even oxygen) would be a definite sign of life. But multiple life-related molecules detected in the atmosphere of a planet with other suitable conditions (such as a comfy temperature) would be strong evidence. Under Earth-like conditions, various molecules, such as oxygen, ozone, methane, carbon dioxide, nitrous oxide and ammonia could be taken as indicators of biological activity.
“Though there is no single ideal molecule, the combination of multiple species (e.g., oxygen and methane) may be a potential biosignature under the given conditions,” wrote Madhusudhan, of the University of Cambridge in England. “In this regard, a detection of oxygen and methane and/or nitrous oxide along with liquid water on a habitable-zone planet, i.e., an almost exact Earth analog, may be a sure sign of life.”
Astronomers studying planets orbiting stars other than the Sun learn about a variety of molecules in those planets’ atmospheres by probing different wavelengths of light, including visible light (optical) and ultraviolet and infrared radiation. Scientists propose that certain combinations of molecules, such as water (H2O) and methane (CH4), could be signs of lifeKnowable Magazine after N. Madhusudhan/AR Astronomy and Astrophysics 2019
Finding primitive extraterrestrial life would be front-page news (or set a record for clicks), but the grand prize is reserved for the “I” in SETI — intelligent life. SETI searches seek signs of technology produced by extraterrestrial intelligence, most likely in the form of “unnatural” radio waves.
In fact, an alien looking for life in the cosmos might very well spot Earth as inhabited by exactly that method. In the 1990s, Carl Sagan and colleagues took advantage of the Galileo spacecraft’s pass by Earth to probe our planet for telltale signals of our existence. The giveaway was narrow-band radio emissions (abundant signaling at a single radio frequency).
“That as far as we know is an unmistakable indicator of technology, and an unmistakable indicator of life,” Siemion said at the AAAS meeting. “And indeed it is the most detectable signature of life on this planet as viewed from a distant vantage point.”
For now, Earth-based radio telescopes listening to the cosmos might hear a deliberate message, but couldn’t pick up TV shows or other radio-wave “leakage” from alien civilizations. But the Next Generation Very Large Array, now in the planning stage, would have the power to receive such unintentional communication, at least from nearby stars.
Perhaps alien civilizations may make more use of lasers than radio, though, which makes the prospect of Laser SETI appealing. But whether patterns are found in the radio or optical region of the electromagnetic spectrum doesn’t matter — such patterns could reveal intelligent activity regardless of their purpose, Siemion pointed out.
“We simply look for compression of electromagnetic energy in time or in frequency or some kind of modulation that is inconsistent with the astrophysical background or the instrumental background and consistent with something that technology could produce,” he said. “So it doesn’t matter if it’s a laser communication system being used to communicate with a spacecraft in some exoplanet system or it’s a giant laser light show that some very advanced civilization produced for the amusement of all the life in their system.”
A map shows the planned spiral-shaped array of 244 fixed radio antennas, most nearly 60 feet across, that will make up the Next Generation Very Large Array telescope. Centered in the US Southwest and Mexico with arms as far as Hawaii and the Caribbean, the ngVLA will be sensitive enough to detect radio wave “leakage” (unintentional signals, such as TV shows) from the nearest stars.NRAO
In any event, receiving a message would be a monumental revelation about the viability of technological civilizations. Nobody knows whether a society that has developed advanced technology can long survive.
“The lifetime of a technological civilization … is a very difficult thing to predict,” said Siemion. “And of course, looking around at our own civilization you have reason to question what that term might be.”
On the other hand, a signal from space would almost certainly be from a civilization that has existed much longer than ours. (Otherwise the likelihood of listening in at exactly the right time would be prohibitively small.) So merely receiving a message might be considered hope that civilization on Earth might not be doomed after all.
Success in receiving a message raises other issues. For one thing, it’s a real possibility that an alien message is clearly an attempt to communicate, but in a language that no earthling could understand. And understood or not, a message received suggests the need to consider a reply. SETI researchers have long agreed that if a signal is detected, no response would be made until a global consensus had been reached on who will speak for Earth and what they would say. But that agreement is totally unenforceable, Tarter pointed out, and nobody has any idea about how to reach a global consensus on anything. (Perhaps the proper reply would just be “HELP!”)
Still, contemplating a response is for the moment a lesser priority than finding a message in the first place. And that might require help from nonhuman intelligence right here on Earth in the form of advanced computers. Recent developments in artificial intelligence research should soon make machine learning an effective tool in the E.T. search, Tarter said at the AAAS meeting.
“The ability to use machine learning to help us find signals in noise I think is really exciting,” she said. “Historically we’ve asked a machine to tell us if a particular pattern in frequency and time could be found. But now we’re on the brink of being able to say to the machine, ‘Are there any patterns in there?’”
So it’s possible that an artificially intelligent computer might be the first earthling to discern a message from an extraterrestrial. But then we would have to wonder, would a smart machine detecting a message bother to tell us? That might depend on whom (or what) the message was from.
“I think there’s something particularly romantic,” said Siemion, “about the idea of machine learning and artificial intelligence looking for extraterrestrial intelligence which itself might be artificially intelligent.”
NASA’s Voyager 2, initially launched in 1977 to study our star system’s outer planets, is currently in interstellar space billions of miles from Earth. In January, the probe experienced a serious glitch that affected a host of crucial scientific instruments.
But luckily, the record-breaking spacecraft is back online.
“The five operating science instruments, which were turned off by the spacecraft’s fault protection routine, are back on and returning normal science data,” NASA’s Jet Propulsion Lab wrote in an update.
Voyager 2 currently is racing through interstellar space at a distance of about 11.5 billion miles (18.5 billion kilometers) from Earth. That means any communications take 17 whole hours to reach it, according to NASA — and another 17 to make it back. Understandably, that’s making the task of fixing the spacecraft’s software very tricky.
The glitch was caused by a “fault protection software routine” after Voyager 2 failed to calibrate itself by spinning around its axis on January 25. Two systems were left running at relatively high levels of power, causing the spacecraft to “overdraw its available power supply.”
In December 2018, 40 years after it was launched into space, Voyager 2 became the second human-made object to exit the heliosphere, the Sun’s protective bubble around the Solar System. Its twin spacecraft Voyager 1 was the first, reaching interstellar space in 2012.
And Voyager 1 is glad to have its twin back online, the space agency joked.
“All right now, baby, it’s all right now! My twin, Voyager 2, is back to normal operations,” tweeted NASA’s official Voyager account.
A gigantic asteroid almost as large as Mount Everest is zooming toward Earth next month, but NASA says not to worry — it’s not expected to collide with our planet.
The space rock is called 52768 (1998 IR2) and was first seen 22 years ago. According to the space agency, early in the morning on Wednesday, April 29, it will pass within 3,908,791 miles of Earth, moving at 19,461 miles per hour.
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“[The asteroid’s discovery comes] on the heels of last month’s installation of new state-of-the-art computing and data analysis hardware that speeds our search for near-Earth objects,” said NEAT Project Manager Steven Pravdo of JPL in a statement at the time of the asteroid’s discovery. “This shows that our efforts to find near-Earth objects are paying off.”
An illustration shows a rocket approaching an asteroid that’s drifted too close to Earth. A scout probe orbits nearby. (Christine Daniloff, MIT)
Although the asteroid, which is between 1 and 2.5 miles wide, is classified as potentially hazardous because of how close it will be to Earth’s orbit, NASA scientists have not put it on the agency’s list of potential future impact events.
“Our goal is to discover and track all the potentially dangerous asteroids and comets long before they are likely to approach Earth,” said NEAT Principal Investigator Eleanor Helin.
NASA students discovered a new black hole 30,000 light years away.
In November 2019, the student-built Regolith X-Ray Imaging Spectrometer (REXIS) onboard NASA’s OSIRIS-REx spacecraft detected a newly flaring black hole in the constellation Columba while making observations off the limb of asteroid Bennu.
“Our initial checks showed no previously cataloged object in that position in space,” Branden Allen, a Harvard research scientist and student supervisor who first spotted the source in the REXIS data, said in a statement.
According to NASA, the glowing object turned out to be a newly flaring black hole X-ray binary.
An instrument developed by students at MIT and Harvard picked up a flare of X-rays from a black hole that is now named MAXI J0637-430. (NASA)
“Detecting this X-ray burst is a proud moment for the REXIS team. It means our instrument is performing as expected and to the level required of NASA science instruments,” said Madeline Lambert, an MIT graduate student who designed the instrument’s command sequences that revealed the black hole, in a statement.
X-ray blasts can only be seen from space because Earth’s protective atmosphere shields our planet from X-rays.
The purpose of the REXIS instrument is to train the next generation of scientists and engineers in the creation of and operation of spaceflight hardware, NASA said.
“We set out to train students how to build and operate space instruments,” said MIT professor Richard Binzel, instrument scientist for the REXIS student experiment. “It turns out, the greatest lesson is to always be open to discovering the unexpected.”
If you ask yourself what the biggest threat to human existence is you’d probably think of nuclear war, global warming or a large-scale pandemic disease. But assuming we can overcome such challenges, are we really safe?
Living on our blue little planet seems safe until you are aware of what lurks in space. The following cosmic disasters are just a few ways humanity could be severely endangered or even wiped out. Happy reading!
1. High energy solar flare
Our sun is not as peaceful a star as one might initially think. It creates strong magnetic fields that generate impressive sun spots, sometimes many times larger than Earth. It also ejects a stream of particles and radiation – the solar wind. If kept in check by Earth’s magnetic field, this wind can cause beautiful northern and southern lights. But when it becomes stronger, it can also influence radio communication or cause power outages.
The most powerful magnetic solar storm documented hit Earth in 1859. The incident, called the Carrington Event, caused huge interference with rather small scale electronic equipment. Such events must have happened several times in the past, too, with humans surviving.
But only in recent years have we become entirely dependent on electronic equipment. The truth is we would suffer greatly if we underestimate the dangers of a possible Carrington or even more powerful event. Even though this would not wipe out humanity instantly, it would represent an immense challenge. There would be no electricity, heating, air conditioning, GPS or internet – food and medicines would go bad.
We are at the starting point of envisaging and developing systems for protecting us against some of the smaller asteroids that could strike us. But against the bigger and rarer ones we are quite helpless. While they would not always destroy Earth or even make it uninhabitable, they could wipe out humanity by causing enormous tsunamis, fires and other natural disasters.
3. Expanding sun
Where the previous cosmic dangers occur at the roll of a dice with a given probability, we know for certain that our sun will end its life in 7.72 billion years. At this point, it will throw off its outer atmosphere to form a planetary nebula, ending up as a stellar remnant know as a “white dwarf”.
But humanity will not experience these final stages. As the sun becomes older, it will become cooler and larger. By the time it becomes a stellar giant it will be big enough to engulf both Mercury and Venus. Earth might seem safe at this point, but the sun will also create an extremely strong solar wind that will slow down the Earth. As a result, in about 7.59 billion years, our planet will spiral into the outer layers of the hugely expanded dying star and melt away forever.
4. Local gamma ray burst
Extremely powerful outbursts of energy called gamma ray bursts can be caused by binary star systems (two stars orbiting a common centre) and supernovas (exploding stars). These energy bursts are extremely powerful because they focus their energy into a narrow beam lasting no longer than seconds or minutes. The resulting radiation from one could damage and destroy our ozone layer, leaving life vulnerable to the sun’s harsh UV radiation.
Astronomers have discovered a star system – WR 104 – that could host such an event. WR 104 is about 5,200-7,500 light years away, which is not far enough to be safe. And we can only guess when the burst will happen. Luckily, there is the possibility that the beam could miss us entirely when it does.
5. Nearby supernovas
Supernova explosions, which take place when a star has reached the end of its life, occur on average once or twice every 100 years in our Milky Way. They are more likely to occur closer to the dense centre of the Milky Way and we are about two-thirds of the way from the middle – not too bad.
So can we expect a nearby supernova anytime soon? The star Betelgeuse – a red super giantnearing the end of its life – in the constellation of Orion is just 460-650 light years away. It could become a supernova now or in the next million years. Luckily, astronomers have estimated that a supernova would need to be within at least 50 light years of us for its radiation to damage our ozone layer. So it seems this particular star shouldn’t be too much of a concern.
6. Moving stars
Meanwhile, a wandering star on its path through the Milky Way might come so close to our sun that it would interact with the rocky “Oort cloud” at the edge of the solar system, which is the source of our comets. This might lead to an increased chance of a huge comet hurtling to Earth. Another roll of the dice.
The sun itself follows a path through the Milky Way that takes us through more or less dense patches of interstellar gas. Currently we are within a less dense bubble created by a supernova. The sun’s wind and solar magnetic field help create a bubble-like region surrounding our solar system – the heliosphere – which shields us from interacting with the interstellar medium. When we leave this region in 20,000 to 50,000 years (depending on current observations and models), our heliosphere could be less effective, exposing Earth. We would possibly encounter increased climate change making life more challenging for humanity – if not impossible.
And life goes on…
The end of humanity on Earth is a given. But this is not something to make us crawl under a table. It is something that we cannot change, similar to our lives having a definite start and end. This is what defines us and makes us realise that the only thing we can do is make the most of our time on Earth. Especially when we know that Earth needs a careful balance to sustain humanity.
All the above scenarios harbour possible destruction, but in every instance they also offer beauty and wonder. In many cases, they produce what allowed us to be created. So rather than looking into the night sky and wondering what will kill us next, we should marvel at the depth of space, the wonders therein and the sublime nature of the universe. Be inspired by space. It offers future and meaning.
AN ASTEROID capable of ending human civilization if it hits will approach our planet in April, NASA’s asteroid trackers have confirmed.
The asteroid is being watched by NASA’s automated tracking systems at the Center for Near Earth Object Studies in California, US. The asteroid has been officially called 52768 (1998 OR2) and is estimated measure up 2.5 miles (4.1km) across.
An object this big could potentially spell the end of the human race if it strikes the planet.
NASA estimates the rock is heading our way at speeds of about 8.7km per second or 19,461mph (31,320kmh).At this rate, the asteroid will close-in on Earth on April 29.
When this happens, NASA said the asteroid will make a “close approach” to our planet.
According to the Planetary Society, an asteroid bigger than 0.6 miles (1km) across is big enough to threaten global destruction.PROMOTED STORY
Asteroid warning: NASA is tracking the movement of a 4.1km space rock (Image: GETTY)
Asteroid warning: NASA said the space rock will make a close approach in April (Image: GETTY)
Astronomers estimate such objects have a one in 50,000 chance of hitting Earth every 100 years.
The Planetary Society lists the following impacts: “A crater of 10km or more: global devastation and possible collapse of civilisation.”
Dr Bruce Betts from the international group of astronomers said: “Small asteroids – few metres – hit frequently and burn up in the atmosphere and do little damage.
“Chelyabinsk size asteroids – about 20m that hit in 2013 – create shock waves that shatter windows and cause injuries.
“Tunguska sized – about 40m that hit Siberia in 1908 – could completely destroy a city or create a tsunami.
“Larger asteroids that hit on average less often could cause regional destruction.
“Even larger asteroids that hit even less frequently could cause a global catastrophe.”
The destructive potential of space rocks this big was also outlined in a 2018 report published by the US National Science and Technology Council.
Even larger asteroids that hit even less frequently could cause a global catastrophe
Dr Bruce Betts, The Planetary Society
The National Near-Earth Object Preparedness Strategy reads: “Objects close to and larger than one kilometre can cause damage on a global scale.
“They can trigger earthquakes, tsunamis, and other secondary effects that extend far beyond the immediate impact area.”
For comparison, the asteroid that is believed to have killed the dinosaurs measured about six miles (10km) across.
Asteroid facts: The differences between asteroids, comets and meteors (Image: EXPRESS/GETTY)
Asteroid warning: The asteroid could end civilisation if it hits (Image: GETTY)
NASA estimates Asteroid 1998 OR2 measures somewhere between 0.9 miles and 2.54 miles (1.5km and 4.1km) in diameter.
The space rock was spotted flying around the Sun in 1987 and NASA confirmed it’s orbit on June 30, 1987.
Astronomers have classed the rock as a “potentially hazardous” NEO or near-Earth object.
But just how close does NASA expect the asteroid to come to Earth next month?
At its closest, the space rock will approach our planet from about 0.04205 astronomical units.
One astronomical unit is the average distance from our planet to the Sun – about 93 million miles (149.6 million km).
Asteroid OR2 will drastically cut this down to just 3.9 million miles (6.29 million km) on April 29.
In other words, the space rock is expected to miss us by about 16.36 times the distance from Earth to the Moon.
Dr Betts said: “There are a few asteroids that currently are known to have a low probability of hitting Earth in tens to hundreds of years.
“For example, one of the highest probabilities currently is an approximately 37m diameter asteroid called 2000 SG344 that has a 1 in 1100 chance of impact in 2071.
“But these always are based on asteroid observations that have uncertainties in them.”
Scientists say they have discovered the first known protein that originated in space, located in a meteorite that fell to Earth 30 years ago.
The meteorite, known as Acfer 086, hit Algeria 30 years ago and contains the protein hemolithin. Inside the hemolithin are iron and lithium, two building blocks for life, the researchers said in the study located on the arXiv repository.
“Analysis of the complete spectrum of isotopes associated with each molecular fragment shows 2H enhancements above terrestrial averaging 25,700 parts per thousand (sigma = 3,500, n=15), confirming extra-terrestrial origin and hence the existence of this molecule within the asteroid parent body of the CV3 meteorite class,” the study’s abstract states. “The molecule is tipped by an iron-oxygen-iron grouping that in other terrestrial contexts has been proposed to be capable of absorbing photons and splitting water into hydroxyl and hydrogen moieties.”
In an interview with ScienceAlert, astronomer and chemist Chenoa Tremblay said it’s believed that proteins are “likely to exist in space,” but this would be the first evidence of such.
“So we’re pretty sure that proteins are likely to exist in space,” Tremblay, who was not involved in the study, told ScienceAlert. “But if we can actually start finding evidence of their existence, and what some of the structures and the common structures might be, I think that’s really interesting and exciting.”
Because the hemolithin in Acfer 086 has a similar structure to proteins on Earth and its ratio of hydrogen to isotope deterium is similar to that seen in the Oort cloud, it’s believed it could have formed nearly 4.6 billion years ago, in the proto-solar disk, the Daily Mail reports.
A study was published in October 2019 that suggested the second interstellar object ever discovered, Comet 2I/Borisov, could be carrying water on it from beyond the solar system, releasing water vapor on its journey.
A separate study published in 2018 suggested that cometlike objects could be “ferrying” microbial life across thousands of light-years.
Our solar system’s second known interstellar visitor appears to be keeping quiet, just like the first.
The Breakthrough Listen SETI (search for extraterrestrial intelligence) project has scanned the interstellar Comet Borisov for “technosignatures” but come up empty so far, scientists announced today (Feb. 14).
Breakthrough Listen also encountered radio silence during an earlier investigation of the mysterious ‘Oumuamua, the first confirmed interstellar object ever spotted in our solar system. The null results may be disappointing to alien enthusiasts out there, but they’re valuable all the same, project team members said.
“If interstellar travel is possible, which we don’t know, and if other civilizations are out there, which we don’t know, and if they are motivated to build an interstellar probe, then some fraction greater than zero of the objects that are out there are artificial interstellar devices,” Steve Croft, a research astronomer with Breakthrough Listen and the Berkeley SETI Research Center at the University of California, Berkeley, said in a statement.
“Just as we do with our measurements of transmitters on extrasolar planets, we want to put a limit on what that number is,” Croft added.
It’s also worth noting that SETI silence does not necessarily guarantee a natural origin for Borisov and ‘Oumuamua. It’s possible, for example, that they’re transmitting a type of signal that we’re not looking for, or that they’re defunct alien craft.
Indeed, a possible artificial origin has been invoked by some scientists — notably, Avi Loeb, the Harvard astronomy department chair — to explain ‘Oumuamua’s very weird combination of characteristics. Loeb has suggested that ‘Oumuamua, which looped around the sun in September 2017, might be a light-sailing alien spacecraft. (Comet Borisov made its closest approach to our star in December 2019.)
The Borisov news is part of a huge data dump by Breakthrough Listen, a $100 million life-hunting effort established in 2016 by billionaire Yuri Milner. During a news conference today at the annual meeting of the American Association for the Advancement of Science in Seattle, project team members announced the release of nearly 2 petabytes of SETI data, much of which astronomers have not yet had a chance to study in detail.
Breakthrough Listen team members said the newly released information represents the most comprehensive survey to date of radio emissions from the plane of our Milky Way galaxy and the region around its central supermassive black hole.
“The galactic center is the subject of a very specific and concerted campaign with all of our facilities, because we are in unanimous agreement that that region is the most interesting part of the Milky Way galaxy,” Breakthrough Listen Principal Investigator Andrew Siemion, of the University of California, Berkeley, said in the same statement.
“If an advanced civilization anywhere in the Milky Way wanted to put a beacon somewhere . . . the galactic center would be a good place to do it,” he added. “It is extraordinarily energetic, so one could imagine that if an advanced civilization wanted to harness a lot of energy, they might somehow use the supermassive black hole that is at the center of the Milky Way galaxy.”
And you have a chance to help turn up evidence of such advanced creatures, if any are there to be found: Breakthrough Listen is inviting the public to help analyze this trove of SETI data.
“Since Breakthrough Listen’s initial data release last year, we have doubled what is available to the public,” Matt Lebofsky, Breakthrough Listen lead system administrator, said in the same statement, referring to a petabyte-size data dump in June 2019. “It is our hope that these data sets will reveal something new and interesting, be it other intelligent life in the universe or an as-yet-undiscovered natural astronomical phenomenon.”
About half of the new data comes from the Parkes radio telescope in New South Wales, Australia, team members said. The rest was collected by the big radio dish at West Virginia’s Green Bank Observatory and the Automated Planet Finder, an optical telescope located at Lick Observatory in California. (SETI signals don’t necessarily have to be in the radio spectrum, after all; laser flashes could betray the presence of intelligent aliens as well.)
Also today, the SETI Institute in Mountain View, California, and the National Radio Astronomy Observatory (NRAO) announced an agreement to start installing technosignature-hunting gear on NRAO dishes.
So, the search for E.T. continues to ramp up, which is just what Milner wants.
“For the whole of human history, we had a limited amount of data to search for life beyond Earth. So, all we could do was speculate,” Milner said in the same statement. “Now, as we are getting a lot of data, we can do real science and, with making this data available to the general public, so can anyone who wants to know the answer to this deep question.”
Late in the day on Thursday, astronomers released this new image of 2020 CD3, a small object now confirmed to be orbiting Earth temporarily. It was apparently captured into Earth orbit 3 years ago. Its fate, here.
Earth’s new mini-moon – officially labeled 2020 CD3 – is the point source in the center of this February 24, 2020, image, obtained with the 8-meter Gemini North telescope in Hawaii. The image combines 3 images each obtained using different filters to produce this color composite. 2020 CD3 remains stationary in the image since it was being tracked by the telescope. The colored streaks are background stars. Image via international Gemini Observatory/ NSF’s National Optical-Infrared Astronomy Research Laboratory/ AURA/ G. Fedorets.
Astronomers have released the new image above of 2020 CD3, the new “temporary captured object” announced by the International Astronomical Union’s Minor Planet Center (MPC) on February 25, 2020. This tiny object was apparently captured into Earth orbit three years ago. Now that more astronomers are trying to catch sight of it, they’ve released a new image and they’ve determined its fate. John Blakeslee, Head of Science at the international Gemini Observatory, commented:
Obtaining the images [see above] was a scramble for the Gemini team because the object is quickly becoming fainter as it moves away from Earth. It is expected to be ejected from Earth’s orbit altogether in April.
In what’s called a Minor Planet Electronic Circular – or MPEC, on February 25 – astronomers said that multiple observations had confirmed:
… this object is temporarily bound to the Earth … no link to a known artificial object has been found. Further observations and dynamical studies are strongly encouraged.
2020 CD3 was discovered on February 15 by astronomers at the Catalina Sky Survey, based in Tucson, Arizona. More than 30 observations were made of the object by February 17, according to asteroid- and comet-hunter Kacper Wierzchos, one of its discoverers along with astronomer Theodore Pruyne. Those observations were needed to refine an orbit for the object, and to confirm it does appear to be orbiting Earth.
What we know about the object so far is that it is orbiting Earth, and that it is very small and faint. Sunlight reflected from it helps provide an estimate of its diameter. The estimate is about 6 to 12 feet (1.9-3.5 meters) at this time, but that could easily change. Still … it’s small! It’s amazing astronomers can identify something so small orbiting Earth.
If it is natural in origin – a captured asteroid – then it is only the second known rocky satellite of the Earth ever discovered in space other than Earth’s large natural moon. The other body, discovered in 2006, has since been ejected out of Earth orbit.
Much of the information we have at this time about the object comes from Wierzchos, who is actively tweeting about it; you’ll find him at @WierzchosKacper. The following tweets are from February 25. Apparently, these astronomers were holding off a bit in speaking openly about the object until the MPEC was published, but now they are telling what they know. Expect more info as the days pass!
BIG NEWS (thread 1/3). Earth has a new temporarily captured object/Possible mini-moon called 2020 CD3. On the night of Feb. 15, my Catalina Sky Survey teammate Teddy Pruyne and I found a 20th magnitude object. Here are the discovery images. pic.twitter.com/zLkXyGAkZl
(2/3) The object has just been announced by the MPC and its orbit shows that it entered Earth’s orbit some three years ago. Here is a diagram of the orbit created with the orbit simulator written by Tony Dunn: pic.twitter.com/2wsJGtexiO
(3/3) The object has a diameter between 1.9 – 3.5 m assuming a C-type asteroid albedo. But it’s a big deal as out of ~ 1 million known asteroids, this is just the second asteroid known to orbit Earth (after 2006 RH120, which was also discovered by the Catalina Sky Survey).
A spectacular fireball (meteor) exploded over northern Balkans today at 10:34 local time (09:34 UTC), Feb 28th. The event was seen and heard from northern Italy, Slovenia, Croatia, and Austria. There are numerous reports of a loud sonic boom with the accompanying shockwave, strong enough to be registered by the seismographs as an earthquake! It is possible some pieces of the object survived the atmospheric entry.
Here is a video of the event as seen over Zagreb, Croatia by Tomislav Čar. A slow-motion sequence of the most interesting part is also included.
Observers who saw the explosion were reporting that it looked like a fireball at night, only it was daytime with a bright flash of light, followed by a loud explosion. For a while, there was a larger yellowish mass in the cloud (probably the meteor was still burning), with then only the smoke cloud remaining. Some of the observers also reported shaking windows during the accompanying shockwave.
Although some residents initially thought it was an airplane breaking the sound barrier (sonic boom) or an earthquake, the Croatian Astronomical Union (CAU) confirmed it was a bolide (fireball meteor) – an extremely bright meteor.
The sonic boom was registered in capital Zagreb at 09:34 UTC, three minutes after the visual spectacle. The sound lasted for several seconds and was heard across northern Croatia.
According to the CAU, the meteor exploded at a height of about 30 km (18.6 miles) above the ground. It is quite possible that some pieces survived atmospheric entry, but it’s still unclear where they might have landed. There are some unofficial reports, a piece of the object was found in the city of Koprivnica, northeast Croatia.
Seismographs of Slovenian meteorological agency (ARSO) and Seismological survey by the University of Zagreb, Faculty of Science, Geophysical department clearly registered the shock waves! It was probably a breakthrough of the sonic boom caused by the meteor explosion. See the charts below:ARSO potresi@ARSO_potresi
Državna mreža potresnih opazovalnic je ob 10.32 zabeležila padec meteorita. Slika prikazuje zapis dogodka na potresni opazovalnici Črešnjevec.
You’ve heard of the “big bang” theory regarding the start of the universe?
Scientists say they recently detected a similar deep-space explosion, up to five times more powerful than any such blast observed previously.
“In some ways, this blast is similar to how the eruption of Mount St. Helens in 1980 ripped off the top of the mountain,” lead study author Dr. Simona Giacintucci of the Naval Research Laboratory in Washington, D.C., told the BBC, referring to the volcano in Washington state.
When did the blast happen?
“It happened very slowly — like an explosion in slow motion that took place over hundreds of millions of years,” Professor Melanie Johnston-Hollitt, of the Curtin University node of the International Centre for Radio Astronomy Research, told Science Daily.
“It happened very slowly — like an explosion in slow motion that took place over hundreds of millions of years.”— Professor Melanie Johnston-Hollitt
One year after the launch of Beresheet we’ve not had much information from official sources about how exactly the spacecraft failed leading to its crash into the lunar surface. However a new article on an Israeli news site by an individual close to the project offers up a few bits of information which weren’t previously in the public sphere. The article is in Hebrew, but the google translation is pretty good and has been confirmed by individuals who understand the language.
https://www.ynet.co.il/articles/0,734… However we still don’t have the level of detail on the operation of the computer, its software extensions and the process for starting the main engine, so there may be more to find out in the future.
The annotated area in this illustration shows where water ice is located near the surface of Mars. (Credits: NASA/JPL-Caltech)
Scientists think if there is life on Mars it’s likely to be hidden in deep underground caves.
This theory is supported by NASA experts and the U.S. space agency will be sending a new rover to the red planet this summer.
According to Space.com, NASA Jet Propulsion Laboratory research scientist Vlada Stamenković explained the Martian underground life theory at a recent space event.
Speaking at the Mars Extant Life conference, Stamenković reportedly said: “The surface of Mars is a very oxidizing, radiation-heavy environment where liquid water is not really stable for an extended amount of time.
“It’s the worst place to look for life-sites on Mars.
“Groundwater might be the only habitat for extant life on Mars, if it still exists today.”
The surface of Mars is cold, dry and there is lots of radiation.
Underground could be more habitable for life forms and may have some form of stable water supply.
Some scientists think that agile robots should be made that could try and explore the cave systems on Mars.
More than 1,000 potential cave entrances have been mapped on Mars by the US Geological Survey’s (USGS) Astrogeology Science Center.
Building nimble robots to enter all these potential caves would be costly and intricate.
However, Stamenković has proposed that Nasa could use a rover that could sense underground groundwater or chemicals associated with life from the surface.
This would make it easier to target specific areas that life is most likely to be found.
NASA intends to send its WED rover to Mars later this year.
The plan is for the 2,260-pound space probe to gather new events of life that’s alive or extinct and send Martian samples back to Earth.
An illustration shows a rocket approaching an asteroid that’s drifted too close to Earth. A scout probe orbits nearby. (Credit: Christine Daniloff, MIT)
If a giant object looks like it’s going to slam into Earth, humanity has a few options: Hammer it with a spacecraft hard enough to knock it off course, blast it with nuclear weapons, tug on it with a gravity tractor, or even slow it down using concentrated sunlight.
We’ll have to decide whether to visit it with a scout mission first, or launch a full-scale attack immediately.
In movies, an incoming asteroid is usually a very last-minute shock: a big, deadly rock hurtling right toward Earth like a bullet out of the darkness, with only weeks or days between its discovery and its projected impact. That is a real threat, according to an April 2019 presentation by NASA’s Office of Planetary Defense that Live Science attended. But NASA believes that it’s spotted most of the largest, deadliest objects that have even a small chance of striking Earth — the so-called planet killers. (Of course, there are probably plenty of smaller rocks — still large enough to kill whole cities — that remain undiscovered.)
Because most of the large objects in Earth’s neighborhood are already being closely watched, we’ll likely have plenty of warning before one strikes Earth. Astronomers watch these space rocks as they get near-Earth to see whether they’re likely to cross through one of their “keyholes.” Every Earth-threatening asteroid gets closer and further from Earth at different points in its orbit around the sun. And along that path, near-Earth, it has keyholes. Those keyholes are regions of space that it has to pass through in order to end up on a collision course during its next approach to our planet.
“A keyhole is like a door — once it’s open, the asteroid will impact Earth soon after, with high probability,” Sung Wook Paek, lead author of the study and a Samsung engineer who was an MIT graduate student when the paper was written, said in a statement.
The easiest time to stop an object from hitting Earth is before it hits one of those keyholes, according to the paper. That will keep the object from getting on the route toward an impact in the first place — at which point saving Earth would require far more resources and energy, and involve much more risk.
Paek and his co-authors tossed out most of the more exotic asteroid-deflection schemes out of hand, leaving only nuclear detonation and impactors as serious options. Nuclear detonation is problematic as well, they wrote, because it’s uncertain exactly how an asteroid will behave after a nuclear explosion and because political concerns about nuclear weapons could cause problems for the mission.
In the end, they landed on three options for missions that could reasonably be prepared on short notice if a planet-killer asteroid were spotted heading toward a keyhole:
A “type 0” mission where a single, heavy spacecraft was fired at the incoming object, aimed using the best available information about the object’s makeup and trajectory to knock it off course.
A “type 1” mission where a scout is launched first and collects close-up data about the asteroid before the main impactor is launched, in order to better aim the shot for maximum effect.
A “type 2” mission where one small impactor is launched at the same time as the scout to knock the object a bit off course. Then all the information from the scout and the first impact are used to fine-tune a second small impact that finishes the job.
The problem with “type 0” missions, the researchers wrote, is that telescopes on Earth can only gather rough information about planet killers, which are still faraway, dim, relatively small objects. Without precise information on the object’s mass, velocity, or physical makeup, the impactor mission will have to rely on some imprecise estimates, and has a higher risk of failing to properly knock the incoming object out of its keyhole.
Type 1 missions are more likely to succeed, the researchers wrote, because they can determine the incoming rock’s mass and velocity far more precisely. But they also take more time and resources. Type 2 missions are even better, but take yet more time and resources to get underway.
The researchers developed a method for calculating which mission is best based on two factors: the time between the mission start and the date the planet killer will reach its keyhole, and the difficulty involved in properly diverting the specific planet killer.
Applying those calculations to two well-known planet-killer asteroids in Earth’s general neighborhood, Apophis and Bennu, the researchers came up with a complex set of instructions for future asteroid deflectors in the event one of those objects started heading for a keyhole.
Given enough time, they found, type 2 missions were almost always the right way to deflect Bennu. If time was short, though, a quick-and-dirty type 0 mission was the way to go. There were just a handful of instances where type 1 missions made sense.
Apophis was a different, more complicated story. If time was short, a type 1 mission was usually the best option: collect data quickly in order to properly aim the impact. Given more time, type 2 missions were sometimes better, depending how difficult it appeared to be to deflect from its course. There were no situations where a type 0 mission made sense for Apophis.
In both cases, if the time got too short, the researchers found no mission would be successful at diverting the rock.
The differences between the rocks came down to the level of uncertainty about their masses and velocities, as well as how their internal materials would react to an impact.
These same basic principles could be used to study other potential planet killers, and future studies could incorporate other options for deflecting the asteroids, including nuclear weapons, the researchers wrote. The more complex the list of options, the more difficult the calculation gets. Eventually, they wrote, it would be useful to train machine learning algorithms to make decisions based on the exact available data in any planet-killer scenario.
I’ve lost count of the number of times I’ve read that the “first Earth-like exoplanet” has been discovered. With nearly 2000 exoplanets found to date, it is no wonder so many of them will resemble our planet in some way. But which exoplanets are similar enough to the Earth that they could actually be habitable?
Many of the claims about the habitability of exoplanets are greatly exaggerated. The exoplanet GJ1132b was just announced by the MEarth project, as “arguably the most important planet ever found outside the solar system”. While it’s one of the nearest exoplanets yet discovered, it’s hardly Earth-like – situated close to its host star with a scalding surface temperature of several hundred degrees Celsius.ADVERTISING
Similarly, Tau Ceti e and Kepler 186f have both been touted as Earth twins, but there are other exoplanets out there that are rather more Earth-like.
A good way to estimate how habitable a planet is the Earth Similarity Index (ESI). This number is calculated from the exoplanet’s radius, density, surface temperature and escape velocity, which is the minimum speed needed to break free from the planet’s surface. For many exoplanets, we don’t have all these measurements, so some of them have to be estimated based on the best available information. The ESI ranges from 0 to 1 and anything with an ESI above 0.8 may be considered “Earth-like”. In our solar system, Mars scores 0.64 (the same as Kepler 186f) while Venus comes in at 0.78 (the same as Tau Ceti e).
Here are the five top candidates for an Earth-twin, based on their ESI values.
1. Kepler 438b
Kepler 438b (ESI=0.88) has the highest ESI of any exoplanet known. Discovered in 2015 around a red dwarf star, significantly smaller and cooler than our sun, it has a radius only 12% larger than Earth’s. It orbits the star, which is 470 light years from Earth, every 35 days and is in its habitable zone, the region around a star which is neither too hot nor too cold for orbiting planets to support liquid water on the surface.
As with other discoveries by Kepler around faint stars, the planet’s mass has not been measured, but if its composition is rocky, it may be only 1.4 times that of the Earth’s with a surface temperature between 0°C and 60°C. However, the ESI is not a foolproof method for classifying the Earth-like nature of a planet. It has recently been found that Kepler 438b’s host star regularly sends out powerful flares of radiation, which may render the planet uninhabitable after all.
2. Gliese 667Cc
Gliese 667Cc (ESI=0.85) was discovered in 2011 orbiting a red dwarf in the Gliese 667 triple star system, just 24 light years away. It was found by the radial velocity method, which is a measure of the small movement a star makes as it responds to the gravitational tug of the planet. The planet’s mass has been estimated at 3.8 times the Earth’s, but we don’t know its size. This is because the planet does not pass in front of the star, which would allow us to measure the planet’s radius. With an orbital period of 28 days, it sits in the habitable zone of this cool star, with a possible surface temperature of around 5°C.
3. Kepler 442b
Kepler 442b(ESI=0.84) is a planet 1.3 times the size of the Earth discovered in 2015. It is orbiting a star cooler than the sun, about 1100 light years away. Its orbital period of 112 days places it in its star’s habitable zone, but with a surface temperature that could be as low as -40°C. However, by comparison, the temperature on Mars can be -125°C near its poles in the winter. Once again, the exoplanet’s mass is not known, but if it has a rocky composition, it may be only 2.3 times the mass of the Earth.
These two planets (ESI=0.83 & 0.67) were discovered in 2013 with the Kepler telescope, which spotted their transits in front of their host star. This star, located about 1200 light years away from us, is somewhat cooler than the sun. With planetary radii of 1.6 and 1.4 times that of the Earth respectively, their orbital periods of 122 and 267 days mean that they both fall within the star’s habitable zone. As with many other planets discovered by Kepler, their masses have not been measured, but are estimated at over 30 times the mass of the Earth in each case. The temperatures of each could permit liquid water to exist on their surfaces, depending on their atmospheric composition.
5. Kepler 452b
Kepler 452b (ESI=0.83) was discovered in 2015 and was the first potentially Earth-like planet orbiting in the habitable zone of a star similar to our Sun. The planet’s radius is 1.6 times that of the Earth and it takes 385 days to orbit its star, which is 1400 light years away. Because the star is too faint to measure its movement due to the gravitational tug by Kepler 452b, the planet’s mass is unknown. However it has been predicted to be at least five times that of the Earth and the planet’s surface temperature is estimated between -20°C and +10°C.
As we have seen, even the most Earth-like of these planets may not be able to support life due to the activity of its star, which can be very different to our sun. Others have a size or temperature that is slightly on the extreme side. But given the rate of exoplanet discovery, it is not impossible that we will detect a planet that truly has the same mass and size as the Earth and is in a similar orbit around a sun-like star in the next decade. If not, ESA’s PLATO spacecraft, due for launch in 2024, will certainly have a good chance.
Preparing to set foot in an environment lacking gravity and essential tools for survival is not an easy feat and can bring many serious side effects as a result. Learn about some of the major changes astronauts experience when putting their bodies on the line to traverse the universe beyond our planet.
It is very rare that astronomers discover a new population of sources in the sky. A notable example involves the most compact stars known, neutron stars. Even though these stars weigh up to twice the mass of the sun, they occupy a region with the length of Manhattan. Some of these stars generate a beam of radio waves that sweep across our sky periodically like a lighthouse.
In 1967, a 24-year old scientist, Jocelyn Bell Burnell, noticed radio pulses that repeated periodically in her data. Temporarily dubbed “Little Green Man 1,” the source she discovered is now known as a spinning neutron star. It is a member of a vast population of neutron stars, hundreds of millions in our own Milky Way galaxy alone. These are relics from the collapse of massive stellar progenitors which, after consuming the nuclear fuel in their bellies, give birth to neutron stars in a supernova explosion. The regularity of their radio bips made pulsars the best clocks available, up until the last few years when human-made atomic clocks overperformed them.
In the neutron star example, mother nature was far more imaginative than we were. Could history be repeating itself?
In 2007, the astronomer Duncan Lorimer asked his undergraduate student to look through archival data taken in 2001 by the Parkes radio dish in Australia and discovered a bright radio burst. Although the burst lasted a few thousandths of a second similar to the pulse of a pulsar, it did not repeat and it also appeared to have traversed a much larger column of material than the Milky Way can provide. This implied that its source must be located very far away, possibly at the edge of the observable universe. At that distance, the source would need to be billions of times brighter than pulsars, which are mostly detectable within the confines of our own galaxy. In fact, if such a bursting source was placed in the Milky Way, we could have detected it with a cell phone!
Subsequently, many similar bursts were discovered across the sky. They were all labeled as Fast Radio Bursts (FRBs) for lack of a clue regarding their mysterious origin. The universe produced one such burst per second. A small fraction of the known FRBs are repeating, allowing us to pinpoint their distant host galaxy. One source repeats periodically every 16 days.
What is the nature of FRB sources? Should we dub them “Little Green Man 2?”?We have no clue. They could be a mixed bag.
Astronomers are conservative. Given the lack of evidence, the most popular interpretation is that FRBs are newly born neutron stars, only decades old, with an extraordinary magnetic field that generates their powerful radio emission.
But until we uncover a “smoking gun” that produced an FRB, other options should be left on the table. That includes the far-out possibility of an artificial production by an advanced technological civilization. In such a case, the radio beam is most likely not intended for communication because of a simple reason. It takes billions of years for a message to cross the vast scale of the universe. Nobody would have the patience to wait that long for a response. If the message was meant to be received across a much shorter distance, then why waste so much energy on it? The amount required is comparable to the total power of sunlight intercepted by the Earth, converted into a tightly collimated beam of radio waves. This would necessitate a huge engineering project that can only be rationalized for propulsion purposes. Indeed, a powerful beam of light could be used to push a sail that carries a giant spacecraft to the speed of light. In that case, we are detecting the leakage of radiation beyond the boundary of the light-sail as the beam sweeps across our sky. But altogether, given the exceptional amount of power involved, FRBs are not likely to be signals from extraterrestrial civilizations, unless some of them originate nearby.
The enigmatic nature of FRBs illustrates why science is so exciting. As scientists, we should be humble and not be guided by prejudice but by evidence. After all, if we expect the future interpretation of FRBs to resemble the past interpretation of pulsars we will never discover something new.
There are two avenues for a future breakthrough in our understanding of FRBs. One would stem from the detection of nearby sources that are extremely bright and whose environments can be studied in great detail. The second involves the detection of FRBs in other bands of light, such as visible, infrared or x-rays. Any qualitatively new information might offer us a revealing glimpse at the central engine of these beasts.
Scientists suspect Mars is home to volcanic caves, which could be fascinating destinations for future rovers or human explorers. Pits like the one the MRO is investigating could be gateways to these underground worlds.
This particular chasm isn’t giving up any secrets just yet. “We can’t obviously see any tunnels in the visible walls, but they could be in the other walls that aren’t visible,” Beyer wrote.
What lies beneath? For now that’ll have to remain a Mars mystery.
China’s Yutu-2 lunar rover has discovered what appear to be relatively young rocks during its recent exploration activities on the lunar far side.
The Chang’e-4 mission’s rover imaged the scattered, apparently lighter-colored rocks during lunar day 13 of the mission, in December 2019, according to the Chinese-language ‘Our Space‘ science outreach blog.
The specimens, which are quite different from those already studied by the rover, could round out the team’s insights into the geologic history and evolution of the area, called Von Kármán crater.
Closer inspection of the rocks by the rover team revealed little erosion, which on the moon is caused by micrometeorites and the huge changes in temperature across long lunar days and nights. That anomaly suggests that the fragments are relatively young. Over time, rocks tend to erode into soils.
The relative brightness of the rocks also indicated they may have originated in an area very different to the one Yutu-2 is exploring.
Chang’e-4 made a historic, first-ever soft landing on the far side of the moon in January 2019. Von Kármán, a roughly 110-mile-wide (180 kilometers) crater, is around 3.6 billion years old. Lava has flooded it multiple times since its formation, leaving it relatively smooth and dark. The crater itself lies within the South Pole-Aitken Basin, an even more massive and more ancient impact crater.
Dan Moriarty, NASA Postdoctoral Program Fellow at the Goddard Space Flight Center in Maryland, said the size, shape and color of the rocks provide clues to their origin.
“Because [the rocks] all look fairly similar in size and shape, it is reasonable to guess that they might all be related,” he told Space.com. “Chang’e-4 landed on a volcanic mare, [a] basalt patch, and those volcanic materials are much darker than normal lunar highlands crust. If these rocks are indeed brighter than the soil, it could mean that they are made up of a higher component of bright, highlands crust materials than the surrounding volcanic-rich soils.”
Moriarty noted that higher-resolution images of the rock would provide more information. “If the rock has the appearance of many heterogeneous fragments ‘welded’ together, this would indicate a regolith breccia,” which are formed by the immense heat of a meteorite impact, he said. “If the rock appears more coherent, then it might be a primary crustal rock excavated by the impact.”
China recently published a huge batch of data and amazing images from the Chang’e-4 lander and Yutu-2 rover. However, the release did not include data from day 13, meaning high-resolution images of these intriguing specimens are not yet public.
Regarding the age of the rocks, Moriarty said that “fresh” is a relative term: In this case, it means that the rocks formed after the major resurfacing events in Von Kármán crater. “So that could be 10-100 million years [ago] or 1-2 billion years. It’s really hard to say definitively.” Click here for more Space.com videos…China’s Historic Moon Landing Captured by Probe’s CameraVolume 0% PLAY SOUND
To learn more, the Yutu-2 team navigated the rover in order to analyze one of the specimens with its Visible and Near-infrared Imaging Spectrometer (VNIS) instrument, which detects light that is scattered or reflected off materials to reveal their makeup.
Because the fragments are small and the lunar terrain is very challenging, the team made careful calculations and fine adjustments in order to get the rocks into the VNIS field of view, according to Our Space. This may account for the relatively short distance Yutu-2 traveled during lunar day 13: 41.3 feet (12.6 meters). Overall, Yutu-2 has driven 1,170 feet (357 m) since arriving in Von Kármán crater.
Earlier in 2019, Yutu-2 made numerous approaches to an unidentified rock sample, which Our Space described as “gel-like.”
The Chang’e-4 lander and Yutu-2 completed their 14th lunar day of science and exploration on Jan. 31, ahead of sunset over the landing area in Von Kármán crater. Day 15 began on Feb. 17, with Yutu-2 due to head to the northwest and then southwest to reach a designated target point.
China plans to launch Chang’e-5, a sample-return mission, in the second half of this year. It will collect around 4 lbs. (2 kilograms) of samples from Oceanus Procellarum on the moon’s near side before returning to Earth. If this is successful, the backup Chang’e-6 mission could attempt to retrieve samples from the South Pole-Aitken Basin or the lunar south pole around 2023.
A huge, heavily cratered asteroid known as Pallas has a violent history, scientists revealed in a new study.
Pallas, which is third largest object in the asteroid belt and named after the Greek goddess of wisdom, can be seen in detailed images published Monday in a study in Nature Astronomy.
Researchers believe that the asteroid’s pockmarked surface is a result of its unique orbit. Pallas has a tilted orbit, so it is basically smashing through the asteroid belt at an angle, unlike most other similar objects.
“Pallas’ orbit implies very high-velocity impacts,” Michaël Marsset, the paper’s lead author and a postdoctoral student in MIT’s Department of Earth, Atmospheric and Planetary Sciences, told MIT News. “From these images, we can now say that Pallas is the most cratered object that we know of in the asteroid belt. It’s like discovering a new world.”
A pair of images show two views of Pallas with its pock-marked surface. (Massachusetts Institute of Technology) (Massachusetts Institute of Technology)
The astronomers obtained 11 series of images, observing Pallas from different angles as it rotated. After pulling the images together, the researchers generated a three-dimensional reconstruction of the shape of the asteroid, in addition to a crater map of its poles.
Thirty-six craters larger than 30 kilometers in diameter were identified, the study notes.
The asteroid’s craters seem to cover at least 10 percent of its surface, which the researchers state in their paper is “suggestive of a violent collisional history.”