The SpaceX mission seeks to raise some $200 million dollars for St. Jude Children’s Research Hospital.
Inspiration4 / John Kraus
Last night at 8:02 PM EDT, the crew of Inspiration 4 — the first all-civilian spaceflight — blasted off from historic Launch Complex 39A at NASA’s Kennedy Space Center. Tucked inside a SpaceX Crew Dragon capsule, which was lofted to orbit atop a SpaceX Falcon 9 rocket, are four fortunate astronauts: Sian Proctor, Hayley Arceneaux, Christopher Sembroski, and Jared Isaacman. The latter footed the bill for the trip.
Unlike the recent suborbital spaceflights of billionaires carried out this summer by Blue Origin and Virgin Galactic, Inspiration4 is setting its sights higher, taking the untrained civilian crew all the way to orbit. There, they will circle the Earth for three days, conducting experiments and enjoying their views before returning for a soft water landing off the coast of Florida.
Although Inspiration4 is currently orbiting more than 100 miles above the International Space Station (ISS), one of the mission’s main goals is much more Earth-bound: to raise awareness and funding for St. Jude Children’s Research Hospital. At St. Jude, children receive treatment for cancer and other life-threatening diseases. And perhaps most importantly, families treated at the hospital never receive a bill. The mission hopes to raise $200 million for St. Jude.
Commanding the Inspiration4 mission is Isaacman, founder and Chief Executive Officer of Shift4 Payments. The American billionaire is also a pilot. Proctor earned her seat by winning a contest hosted by Shift4.
Similarly, Sembroski got his seat from a contest, but not one that he won. Instead, his friend won the seat in a charity raffle for St. Jude and, for personal reasons, declined the seat, instead offering it to Sembroski.
Inspiration4 crew before liftoff. Inspiration4 / John Kraus
Arceneaux was a childhood cancer survivor and former patient at St. Jude who now works at the hospital as a physician’s assistant. She will become the youngest American (and the first person with a prosthetic body part) to venture to space. Arceneaux was personally selected by Isaacman to be on the flight.
Also on board are numerous items that will later be auctioned off for St. Jude, including the first minted non-fungible token (NFT) to be played in orbit. Other items include mission jackets decorated with artwork from St. Jude patients, 66 pounds of hops from Samuel Adams that can be used to create out-of-this-world beer, a to-be-autographed copy of Time with the crew on the cover, and much more.about:blankabout:blank
Inspiration4 / John Kraus
Breaking records left and right
The launch last night went off without a hitch, and it was celebrated with fist bumps by the crew, even as they were still climbing to their final orbital altitude.
Their excitement, however, is warranted. Besides becoming the first all-civilian mission, Inspiration4 will also be the first orbital human space mission to not dock at the ISS since the final Hubble mission in 2009.
At an orbit of 363 miles (585 kilometers), Inspiration4 is now above both the ISS and the Hubble Space Telescope. In fact, the Inspiration4 crew is currently farther from Earth than any humans have been since the Apollo missions.
One more record Inspiration4 launch helped break: the greatest number of people in space at one time. NASA’s Expedition 65 mission currently has a crew of seven people aboard the ISS, while China’s Shenzhou-12 mission includes three astronauts who are concluding a 90-day trip with their return to Earth tomorrow. So for a few brief days, the four civilians of the Inspiration4 crew brings the total space population up to 14, just edging out the previous record of 13 set in 2009.
The Juno spacecraft has gotten a private radio show from Jupiter’s closest moon, the highly volcanic Io.
NASA’sJuno spacecraft is “listening” in on radio emissions from Jupiter’s volcanic moon Io, allowing researchers to discover what triggers the strange radio waves.
Of all the planets in our solar system, Jupiter has the largest and most powerful magnetic field, which extends so far that some of the planet’s moons orbit within it. Because Io is closest to the planet, the moon is “caught in a gravitational tug-of-war” between Jupiter and two other large moons, according to NASA. These opposing pulls cause massive internal heat, which has led to hundreds of volcanic eruptions across the moon’s surface.
The volcanos release 1 ton of gasses and particles per second into space, NASA said in a statement. Some of this material splits into electrically charged ions and electrons that then rain down onto Jupiter through the planet’s magnetic field. Electrons caught in the magnetic field are accelerated toward Jupiter’s poles and, along the way, generate a phenomenon scientists call decameter radio waves (also known as decametric radio emissions, or DAM).
When the spacecraft is in the right spot to listen, Juno’s Waves instrument can pick up these radio waves, Yasmina Martos of NASA’s Goddard Space Flight Center said in the statement. Researchers have used data from Juno to pinpoint where in Jupiter’s massive magnetic field the radio emissions come from. The data sheds light on the behavior of the enormous magnetic fields gas giants create.
According to the research team, the radio waves come from space that can be described as a hollow cone, where the conditions are just right: the right magnetic field strength and the right density of electrons. The signal rotates like a lighthouse and Juno picks it up only when the “light” is shining on the spacecraft, according to the NASA statement.
The radio data also showed that the electrons that create these radio waves emit a massive amount of energy, 23 times greater than researchers expected. Such electrons can come from other sources, too, such as from the planet’s magnetic field or from a solar wind, according to the research team.
With humans likely the threat, Tokyo needs to lend its eyes on the sky
People look at the night sky using night vision goggles during an UFO tour in the desert outside Sedona in the U.S. state of Arizona.
TOKYO — Gone are the days when UFO stories were dismissed as crackpot pseudoscience. Today, they are an emerging field of public policy debate.
A recent U.S. report on unidentified flying objects, or what the intelligence community calls unidentified aerial phenomena (UAP), has brought these mysterious sightings into the realm of serious discussion on national security.
The world’s powers need to take note. Japan and European allies of the U.S. should work on sharing information on UAP to learn more about them and assess potential security risks.
The report released on June 25 by the Office of the Director of National Intelligence examines 144 incidents of UAP gathered since 2004, mainly by the U.S. military. Most of them are from the past two years.
For many readers, the nine-page document raised more questions than it answered. Of the 144 reported UAP sightings, the Pentagon task force that examined the episodes could offer a reasonable explanation for only one case, identified as “a large, deflating balloon.” The rest remain unexplained.
In 18 incidents, unusual UAP movement patterns or flight characteristics were observed. “Some UAP appeared to remain stationary in winds aloft, move against the wind, maneuver abruptly, or move at considerable speed, without discernible means of propulsion,” according to the report. There are also 11 reports of near misses between the observing aircraft and a UAP.
The report is based on the work of the Department of Defense’s Unidentified Aerial Phenomena Task Force, set up in August 2020 in response to a flurry of UAP sightings in recent years. At a glance, the document seems to be a feast for UFO believers and conspiracy theorists. But far from being that, it reflects the growing interest in these phenomena among U.S. policymakers.ADVERTISING
After the release of the report, some U.S. lawmakers and security experts called for redoubled efforts to determine the truth behind UAP. “The United States must be able to understand and mitigate threats” posed by UAP, said Sen. Mark Warner, a Democrat from Virginia who serves as chairman of the Senate Select Committee on Intelligence.
Republican Sen. Marco Rubio of Florida concurred, saying, “The Defense Department and intelligence community have a lot of work to do before we can actually understand whether these aerial threats present a serious national security concern.”
The Pentagon is willing to respond to such calls. In late June, Deputy Secretary of Defense Kathleen Hicks directed the Office of the Under Secretary of Defense for Intelligence and Security to develop a plan to formalize the UAP task force’s activities.
A U.S. security expert with knowledge of discussions on this topic in the Biden administration said civilian and military officials are primarily worried that some aerial sightings may be linked to foreign countries or groups hostile to the U.S.
This is a more palpable threat than invading aliens. Even if intelligent life exists elsewhere in the vast universe, the sheer distances involved make it unlikely that such beings are visiting Earth at anywhere near the pace of reported UAP sightings.
Professor Hitoshi Murayama, a well-known theoretical particle physicist teaching at the University of California, Berkley, explained.
“Any planet with an environment similar to that of Earth is thought to be at least about four light years away from us,” Murayama said.
“Shuttling between such a planet and Earth would take an incredibly long time even with extremely sophisticated technology,” he said. “If extraterrestrial visitors are involved [in any of the UAP], it is hard to understand how they travel to the Earth so frequently.”
Existing earthly spaceships would take about 30,000 years to travel to a planet four light years away. Even for civilizations with far more advanced technology, the distance would be a daunting hurdle. These scientific assumptions support the view that UAP are human in origin. If so, at least some of the sightings may involve unknown highly advanced technology from countries like Russia or China, possibly representing a serious security threat to the U.S.
Multiple military experts warn that objects capable of the otherworldly flight characteristics reported in some UAP were used for military purposes, intercepting or tracking them with existing weapons systems would be next to impossible. Some UAP reports by the U.S. forces exhibit high-level stealth capabilities that defy radar detection.
The report mentions the possibility of “technologies deployed by China, Russia, another nation, or a nongovernmental entity.” But it admits there is no solid evidence to support such claims.
The report also suggests some UAP observations could be attributable to classified programs undertaken by the U.S. government or industry. If this is the case, however, such programs have been going on without the knowledge of top U.S. intelligence and defense officials.
The report does not necessarily rule out the involvement of alien visitors. Christopher Mellon, former deputy assistant secretary of defense for intelligence during the Clinton and George W. Bush administrations, argued for taking the alien theory seriously in a blog post on the UAP report.
“In my view, the UAP report’s findings strengthen the case for the alien hypothesis by undermining the main alternatives and providing examples of capabilities we cannot emulate or even understand,” Mellon said.
The topic should also raise security red flags for Japan and other U.S. allies that depend on the American military for their defense. Any technology unknown to the U.S. that defies responses by its military, whether human or extraterrestrial in origin, could pose a serious potential threat.
Closer cooperation between the U.S. and its allies on sharing and studying UAP sightings is essential. Most of the 144 UAP episodes covered by the report occurred in or around U.S. airspace.
If a foreign state or group is developing advanced weapons, chances are it will conduct more tests in other parts of the world rather than risk exposing its work to the Americans. If Russia or China were involved, Japan might be in a better geographical position than the U.S. to gather information about the technology.
Japan is beginning to take a minimum response to the challenge. Last September, one month after the U.S. set up the UAP task force, then Defense Secretary Taro Kono issued an unusual order to the Self-Defense Forces to take visual records and analyze such sightings.
During his meeting last summer with then-U.S. Defense Secretary Mark Esper, Kono raised the topic and agreed with the Pentagon chief to share information.
Traveling to space has become a thing among the world’s multibillionaires. This month, Virgin Group founder Richard Branson rode into space aboard a rocket he helped fund, followed less than two weeks later by Amazon.com founder Jeff Bezos.
But humans know only a sliver of the vast universe. While lawmakers and news media should still never feed wild alien conspiracy theories, the U.S. report has spelled the end of the taboo on discussing UFOs in the public policy sphere.
Astronomers have obtained the sharpest and most detailed images yet of the asteroid Kleopatra. The observations have allowed the team to constrain the 3D shape and mass of this peculiar asteroid, which resembles a dog bone, to a higher accuracy than ever before. Their research provides clues as to how this asteroid and the two moons that orbit it formed.
Using the European Southern Observatory’s Very Large Telescope (ESO’s VLT), a team of astronomers have obtained the sharpest and most detailed images yet of the asteroid Kleopatra. The observations have allowed the team to constrain the 3D shape and mass of this peculiar asteroid, which resembles a dog bone, to a higher accuracy than ever before. Their research provides clues as to how this asteroid and the two moons that orbit it formed.
“Kleopatra is truly a unique body in our Solar System,” says Franck Marchis, an astronomer at the SETI Institute in Mountain View, USA and at the Laboratoire d’Astrophysique de Marseille, France, who led a study on the asteroid — which has moons and an unusual shape — published today in Astronomy & Astrophysics. “Science makes a lot of progress thanks to the study of weird outliers. I think Kleopatra is one of those and understanding this complex, multiple asteroid system can help us learn more about our Solar System.”
Kleopatra orbits the Sun in the Asteroid Belt between Mars and Jupiter. Astronomers have called it a “dog-bone asteroid” ever since radar observations around 20 years ago revealed it has two lobes connected by a thick “neck.” In 2008, Marchis and his colleagues discovered that Kleopatra is orbited by two moons, named AlexHelios and CleoSelene, after the Egyptian queen’s children.advertisementMotegrity® (Prucalopride) – Official Physician SiteSee Motegrity Dosing and Administration Information at the Official Physician Site.www.motegrityhcp.com
To find out more about Kleopatra, Marchis and his team used snapshots of the asteroid taken at different times between 2017 and 2019 with the Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) instrument on ESO’s VLT. As the asteroid was rotating, they were able to view it from different angles and to create the most accurate 3D models of its shape to date. They constrained the asteroid’s dog-bone shape and its volume, finding one of the lobes to be larger than the other, and determined the length of the asteroid to be about 270 kilometres or about half the length of the English Channel.
In a second study, also published in Astronomy & Astrophysics and led by Miroslav Brož of Charles University in Prague, Czech Republic, the team reported how they used the SPHERE observations to find the correct orbits of Kleopatra’s two moons. Previous studies had estimated the orbits, but the new observations with ESO’s VLT showed that the moons were not where the older data predicted them to be.
“This had to be resolved,” says Brož. “Because if the moons’ orbits were wrong, everything was wrong, including the mass of Kleopatra.” Thanks to the new observations and sophisticated modelling, the team managed to precisely describe how Kleopatra’s gravity influences the moons’ movements and to determine the complex orbits of AlexHelios and CleoSelene. This allowed them to calculate the asteroid’s mass, finding it to be 35% lower than previous estimates.
Combining the new estimates for volume and mass, astronomers were able to calculate a new value for the density of the asteroid, which, at less than half the density of iron, turned out to be lower than previously thought . The low density of Kleopatra, which is believed to have a metallic composition, suggests that it has a porous structure and could be little more than a “pile of rubble.” This means it likely formed when material reaccumulated following a giant impact.
Kleopatra’s rubble-pile structure and the way it rotates also give indications as to how its two moons could have formed. The asteroid rotates almost at a critical speed, the speed above which it would start to fall apart, and even small impacts may lift pebbles off its surface. Marchis and his team believe that those pebbles could subsequently have formed AlexHelios and CleoSelene, meaning that Kleopatra has truly birthed its own moons.
The new images of Kleopatra and the insights they provide are only possible thanks to one of the advanced adaptive optics systems in use on ESO’s VLT, which is located in the Atacama Desert in Chile. Adaptive optics help to correct for distortions caused by the Earth’s atmosphere which cause objects to appear blurred — the same effect that causes stars viewed from Earth to twinkle. Thanks to such corrections, SPHERE was able to image Kleopatra — located 200 million kilometres away from Earth at its closest — even though its apparent size on the sky is equivalent to that of a golf ball about 40 kilometres away.
ESO’s upcoming Extremely Large Telescope (ELT), with its advanced adaptive optics systems, will be ideal for imaging distant asteroids such as Kleopatra. “I can’t wait to point the ELT at Kleopatra, to see if there are more moons and refine their orbits to detect small changes,” adds Marchis.
We have been broadcasting for over 100 years. Now a new 3D map of the galaxy reveals the stars these signals have reached that can also see Earth.
When Guglielmo Marconi made the first “long-distance” radio broadcasts in 1895, his assistant tuned into from a less than a kilometer away. Marconi went on to develop the world’s first commercial radio system and, by the time of his death in 1937, radio signals were routinely used to communicate across the world.
These broadcasts have also travelled into space, signaling to all who care to tune in, that humanity has emerged as a technologically advanced species. The first signals have now been travelling for over hundred years, reaching distances that would have been unimaginable to Marconi.
That raises some interesting questions about the stars these signals have already reached. What kind of stars are they, do they host exoplanets and if so, are any potentially Earth-like and in the habitable zone? How many of these exoplanets might also be able to see us?about:blankabout:blank
Now we get an answer thanks to the work of Lisa Kaltenegger at Cornell University in Ithaca and Jackie Faherty at the American Museum of Natural History in New York City. These astronomers have calculated the size of the sphere that our radio signals have covered since they left Earth, counted the stars that sit inside it and worked out which of them should also be able to see Earth transiting the Sun.
3D Star Map
All this is made possible by the Gaia Catalogue, a new 3D map of our galaxy showing the distance and motion of more than 100 million stars. The data comes from the European Space Agency’s Gaia spacecraft that was launched in 2013 and is mapping the position and motion of some 1 billion astronomical objects.
The resulting map is giving astronomers an entirely new way to study our galactic environment. Kaltenegger and Faherty’s project is a good example. Since Gaia measures how these stars are moving relative to one another, the researchers can work out for how long we have been visible to them and for how much longer.
Kaltenegger and Faherty say 75 stars systems that can see us, or soon will, sit within this 100 light year sphere. Astronomers have already observed exoplanets orbiting four of them.
These systems are generally well studied. The researchers say, for example, that the Ross128 star system is the 13th closest to the Sun and the second closest with a transiting Earth-size exoplanet. Then there is Teegarden’s Star, with at least two Earth-mass exoplanets and the Trappist-1 star system with seven Earth-sized planets, of which four are in the habitable zone.about:blankabout:blank
Our signals continue to radiate away from us. So Kaltenegger and Faherty also pick out at the star systems set to receive our signals in the next 200 years or so and will also be able to see us. “1,715 stars within 326 light-years are in the right position to have spotted life on a transiting Earth since early human civilization, with an additional 319 stars entering this special vantage point in the next 5,000 years,” they say.
Exoplanet statistics suggest that at least 25 per cent of these stars will have rocky exoplanets. So there should be at least 508 rocky planets in this population with a good view of earth. “Restricting the selection to the distance radio waves from Earth have traveled- about 100 light-years – leads to an estimated 29 potentially habitable worlds that could have seen Earth transit and also detect radio waves from our planet,” say Kaltenegger and Faherty.
Of course, the possibility of life on these worlds is entirely unknown. The next generation of space telescopes should allow astronomers to study these worlds in more detail, to determine their atmospheric make up and perhaps see continents and oceans.
To similarly equipped alien eyes, Earth will have long looked an interesting target. Life first emerged here some 4 billion years ago, ultimately giving our atmosphere its rich oxygen content and its other biomarkers, such as methane. If astronomers find similar conditions elsewhere, that will pique their interest.
It could even prompt searches for radio signals that may already be reaching us from these places. Marconi would surely have been amazed.
Astronomy is a bit different from many sciences because you only have a sample size of 1. The cosmos contains everything we can observe, so astronomers can’t study multiple universes to see how our universe ticks. But they can create computer simulations of our universe. By tweaking different aspects of their simulation, astronomers can see how things such as dark matter and dark energy play a role in our universe. Now, if you are willing to spring for a fancy hard drive, you can keep one of these simulations in your pocket.
The Uchuu simulation is the largest and most detailed simulation of the universe ever made. It contains 2.1 trillion “particles” in a space 9.6 billion light-years across. The simulation models the evolution of the universe across more than 13 billion years. It doesn’t focus on the formation of stars and planets but instead looks at the behavior of dark matter within an expanding universe. The detail of Uchuu is high enough that the team can identify everything from galaxy clusters to the dark matter halos of individual galaxies. Since dark matter makes up most of the matter in the universe, it is the main driver of galaxy formation and clustering.
It takes a tremendous amount of computational power and storage to create such a detailed model. The team used over 40,000 computer cores and 20 million computer hours to generate their simulation, and it produced more than 3 Petabytes of data. That’s 3,000 Terabytes or 3 million Gigabytes for us mortals. Using high-density compression, however, the team was able to compress their results into a mere 100 Terabytes of storage.
That’s still a tremendous amount of data, but it can be stored on a single drive. For example, the Exadrive from Nimbus is a 100 Tb solid-state drive in a standard 3.5-inch form factor. Granted, it will set you back $40,000, but if you have that kind of change hiding between your couch cushions, why not use it to keep a universe in your pocket. Fortunately, if you don’t have that much spare change, you can access the data online. The Uchuu team has their raw data on skiesanduniverses.org, so you can explore their virtual universe all you want.
In addition to being a detailed cosmic simulation, the Uchuu simulation can be used by researchers working on scientific data mining. As large sky surveys and more simulations are created, the data will become so large data mining will play a crucial role in astronomical research. Until that data becomes available, data miners can hone their skills on a pocket universe.
NASA’s Goldstone 70-meter (230 foot) antenna captured radar imagery of asteroid 2016 AJ193 on Aug. 22, 2021 as it passed about 2.1 million miles (about 3.4 million kilometers) away from Earth.
A gigantic asteroid that is considered potentially hazardous by NASA zipped past the Earth at a very high rate of speed. The asteroid, called 2016 AJ193, flew past the Earth at a velocity of 58,000 mph. It’s hard to imagine a speed that high; it equates to traveling about 16 miles every second.
NASA estimates the asteroid is about 4800 feet wide, approximately four times as wide as the Empire State building is tall. The asteroid passes through the solar system every six years on its orbit around the sun. Scientists are taking advantage of its proximity to the Earth on this orbit to study it in detail.
Astronomers observed the asteroid using radar, which is similar to the tech used for tracking thunderstorms on Earth. 2016 AJ193 Is a medium-size Apollo class asteroid. NASA says it’s comparable in size to the Pentagon. At its closest approach to Earth, it passed within 3,427,445 kilometers.
Anyone can tell that it was very far from our planet, but that is considered a close flyby on the astronomical scale of things. The asteroid has an elliptical orbit around the sun, and at its closest point, it’s 0.60 AU from the Sun, and at the furthest point of its orbit is 5.93 AU. An astronomical unit (AU) is the distance the Earth orbits from the sun.
The close approach that happened yesterday was one of only two coming in the near future. 2016 AJ193 will make its next near pass to the earth on August 19, 2080, when it will be 6,999,373 kilometers from Earth. It will have slowed down from its current velocity of 26.169 km/s to 21.713 km/s on that orbit.
NASA is a sprawling organization that has to talk to everything from politicians in Washington DC to space probes that have left the solar system. Discussions with the first might be as simple as a written letter for informal conversation, while the second requires a high-power network of ground-based antennas. Known as the Deep Space Network (DSN) this series of antennas spread over three continents is the backbone of NASA’s communications with its various space probes. Now the DSN is in the process of implementing a well-deserved upgrade.
Part of the reason for that upgrade is the sheer number of spacecraft in deep space NASA has to communicate with. Everything from Voyager to the Parker Solar Probe requires time on the antenna to relay data and receive instructions. But with new missions launching at an increasing pace, the network must be beefed up in order to accommodate all the new communication links.
Currently, DSN supports 39 missions, but NASA has 30 additional missions in development, and not all of the existing missions will be phased out in the near future. To ensure consistent communication no matter where the Earth is on its journey around the sun, the antennas supporting those 30 missions are evenly spread around the globe – in Madrid, Spain, Canberra, Australia, and near Barstow California. When not being used for communication directly, the antennas can serve as data collection platforms for radio science missions as well.
One major component of the upgrade needed to support all this work is the addition of 2 new antennas. The first, a 34-m wide dish named DSS-56 was commissioned in Madrid in January of this year. Also completed this year was an upgrade to DSS-43, a 70-m antenna located in Australia that is the only antenna in the Southern Hemisphere that is capable of sending messages to Voyager, which is currently outside of our solar system.
DSS-43 won’t be the last 70-m antenna improvement either – its equivalents in Madrid and California are slated to receive upgrades soon as well. Increasing the power of those antennas isn’t their only purpose. With so much additional data being sent between handlers and spacecraft, increasing data transfer rates is another focal point of the network upgrades. Eliminating frequency bands that specific telescopes are limited to will help the network utilize all of its resources to support all of its missions.
Not only is the DSN getting technological upgrades, but it’s also trying a new management system that will better utilize the three sites spread throughout the world. Previously, on-site managers had managed the antennas at their site locally. Now, there is a global hand-off protocol that managers call “Follow the Sun”, which allows personnel at each complex to run their entire network during their own “on” shift. This has created cost savings as well as increased coordination between the sites as it requires regular knowledge transfer about local conditions and satellite quirks.
A lot of those cost savings from the new management architecture have gone into technological upgrades for the antennas themselves. With the pace of technological advancement in the communications field, there is plenty of room for improvement, but NASA has already shown that maintaining and even upgrading their internal communication network is one of the priorities.
The Milky Way is filled with planets. Now astronomers have found the first candidate planet in another galaxy.
The M51 Whirpool GalaxyNASA, ESA, S. Beckwith (STScI) and the Hubble Heritage Team (STScI/AURA)Since the first detection of the first exoplanet in 1992, astronomers have found thousands of others. Indeed, they estimate that the Milky Way is home to 40 billion worlds.
So it’s easy to imagine that planets must be common in other galaxies, particularly those that seem similar to our own. But when it comes to spotting these planets, there is a problem.
Other galaxies are so far away and the stars crammed into such a small region of space, as seen from Earth, that it is hard to identify individual ones let alone the effects of any planets around them. So extragalactic planets have sadly eluded astronomers.about:blank
Now Rosanne Di Stefano at the Harvard-Smithsonian Center for Astrophysics along with several colleagues, say they have found a candidate planet in the M51 Whirlpool Galaxy some 23 million light years from Earth near the constellation of Ursa Major. This alien world, christened M51-ULS-1b, is probably slightly smaller than Saturn and orbits a binary system at a distance of perhaps ten times Earth’s distance from the Sun.
The observation was possible because of a special set of conditions. The planet’s host binary system consists of a neutron star or black hole which is devouring a massive nearby star at a huge rate. The infall of stardust releases huge amounts of energy, making this system one of brightest sources of X-rays in the entire Whirlpool Galaxy. Indeed, its X-ray luminosity is roughly a million times brighter than the entire output of the Sun at all wavelengths.
But the source of these X-rays — the black hole or neutron star — is tiny. That means a Saturn-sized planet orbiting a billion kilometers away can completely eclipse the X-ray source, should it pass directly in front in the line of sight with Earth.
On Sep. 20, 2012, that’s exactly what appears to have happened. Fortuitously, the orbiting Chandra X-ray Observatory was watching at the time. The X-ray source dimmed to nothing and then reappeared, the entire transit lasting about 3 hours.about:blank
At the time, nobody noticed because the data sets from Chandra weren’t being searched for such short variations. But when Di Stefano and colleagues looked, the tell tale signs were clear to see.
There are various reasons why an X-ray source can dim in this way. One is the presence of another small star, such as a white dwarf, that eclipses the X-ray source. The team says M51-ULS-1b cannot be a white dwarf or other type of star because the binary system is too young for such an object to have evolved nearby.
Another potential explanation is natural variation, perhaps because of an interruption to the material falling into the black hole or neutron star. Di Stefano and co say in these cases, the luminosity changes in a characteristic way, with higher energy light frequencies changing more quickly than lower energy ones, and switching back on in a different way.
But in this case, all the light frequencies dimmed and reappeared at the same time, suggesting an eclipse. “It is approximately symmetric, and has a shape typical of transits in which the source and transiting object have comparable size,” they say.about:blank
Now that the first planet candidate in another galaxy has emerged, Di Stefano and co say others are likely to be found quickly. The team scoured just a portion of the X-ray data from Chandra to find this new planet candidate.
There is plenty more where that data came from. “The archives contain enough data to conduct surveys comparable to ours more than ten times over,” say the team. “We therefore anticipate the discovery of more than a dozen additional extragalactic candidate planets in wide orbits.” And more data is being gathered all the time.
So while M51-ULS-1b may be the first candidate planet discovered in another galaxy, it is unlikely to be the last. Just watch this space.
The impact site (Southern North America) of the asteroid that killed the dinosaurs 65 million years ago – It is called the Chicxulub Crater ~ 200 Km in diameter.
Asteroid dust found at Chicxulub Crater confirms cause of dinosaurs’ extinction
Although an asteroid impact has long been the suspected cause of the mass extinction 66 million years ago, researchers think new evidence finally closes the case.
An asteroid smashed into the Yucatán Peninsula 66 million years ago, killing some 75 percent of life on Earth, including all non-avian dinosaurs.Willgard Krause/Pixabay
Some 66 million years ago, a city-size asteroid barreled through Earth’s atmosphere and slammed into the shallow waters off the Yucatán Peninsula in the Gulf of Mexico. The cosmic artillery strike gouged a 125-mile-wide (200 km) crater in Earth surface, lofting plumes of vaporized rock and debris into the air that globally blocked out views of the Sun for years or decades. After the initial blast, the reduced sunlight caused Earth’s surface temperature to plummet by as much as 50 degrees Fahrenheit (28 degrees Celsius), aiding in a mass extinction that killed 75 percent of life on Earth.
But eventually, the dust settled.
Fast forward to the 1980s, and scientists uncovered traces of asteroid dust, finding it scattered around the globe within the same geological layer that corresponds to the dinosaurs’ extinction. In the following decade, Chicxulub Crater was discovered in the Gulf of Mexico. And because the crater appeared to be the same age as the global rock layer enriched with asteroid dust, researchers were fairly certain they had the story of the dinosaurs’ demise figured out.about:blankabout:blank
Now, a new study seems to have officially closed the case for good.
Named after a nearby town, Chicxulub crater is located just offshore. New evidence confirms the site is almost undoubtedly the epicenter of the dinosaurs’ demise.The University of Texas at Austin/Jackson School of Geosciences/Google MapsThe latest evidence comes from rock core samples plucked from Chicxulub Crater itself, which is buried beneath the seafloor in the Gulf of Mexico. In the most recent study based on these samples, which were collected during a 2016 mission co-led by the University of Texas at Austin, researchers say they’ve found a telltale sign of asteroid dust. It comes in the form of iridium, which is common in some types of asteroids, yet rare in Earth’s crust.
The researchers found the highest concentration of iridium-peppered rock, which also contains a mixture of ash from the impact and ocean sediment, within a sample taken from the crater’s peak ring. This sample likewise shows elevated levels of other elements commonly associated with asteroids, resulting in a chemical fingerprint that resembles the asteroid dust found around the globe in the 1980s, and precisely matches the geological location of the impact itself.
Seen here is the section of rock core from Chicxulub Crater in which researchers found a concentration of iridium, a tracer for asteroid material, mixed with ash from the impact and ocean sediment.The International Ocean Discovery Program.We combined the results from four independent laboratories around the world to make sure we got this right,” said lead author Steven Goderis, a geochemistry professor at Vrije Universiteit Brussel, in a press release.
“We are now at the level of coincidence that geologically doesn’t happen without causation,” added Sean Gulick, a professor at UT Jackson School of Geoscience and co-author of the study.
Astronomers Say Giant Comets Pose a Greater Threat to Earth Than Asteroids
A team of astronomers has identified giant comets as a greater threat to life on Earth than asteroids. The biggest difference between the two celestial bodies is their composition: comets are composed of ice, dust, and rock, whereas asteroids are made up of metals and rock – which is why comets leave a ‘tail’, as the ice within them gets vapourised by the Sun.
That distinction might not mean much to the average resident of planet Earth, but another major difference between comets and asteroids is where they can be found in the Universe. Giant comets, known as centaurs (around 50-100 km or 31-62 miles across), move through unstable orbits that take them past the larger planets: Jupiter, Saturn, Uranus, and Neptune.
The gravity from these planets can deflect comets in the direction of Earth, and we’re discovering more and more of these centaurs as time goes on.
Researchers from Armagh Observatory and the University of Buckingham in the UK think this makes them a genuine threat to our home planet – more so than the asteroids that typically come closer to Earth on a regular basis, and which have been the main focus of NASA’s investigations so far.
If a centaur heading in our direction should break up into pieces, we could face an intermittent bombardment of missiles that lasts 100,000 years, according to the new report.
“In the last three decades we have invested a lot of effort in tracking and analysing the risk of a collision between Earth and an asteroid,” said one of the team, astronaut Bill Napier. “Our work suggests we need to look beyond our immediate neighbourhood too, and look out beyond the orbit of Jupiter to find centaurs. If we are right, then these distant comets could be a serious hazard, and it’s time to understand them better.”
Based on a study of ancient civilisations, the terrestrial environment and interplanetary matter close to Earth, the scientists think the remnants of a centaur may have hit our planet some 30,000 years ago. Based on a projected frequency of one centaur per 40,000 to 100,000 years, that means we’re almost due for another one.
The cratering patterns found on Earth and the Moon suggest the volume of near-Earth objects (NEOs) is episodic in nature, say the researchers. In other words, it varies significantly over time, and we should be prepared for another sudden increase in the number and frequency of the NEOs we potentially have to deal with. Perhaps the sooner we all vacate the planet, the better.
It could analyze a photo of the Martian surface in just five seconds. NASA scientists need 40 minutes.
If you’ve ever played one of those “spot the difference between these two photos” games, you have something in common with NASA scientists.
To identify newly formed craters on Mars, they’ll spend about 40 minutes analyzing a single photo of the Martian surface taken by the Context Camera on NASA’s Mars Reconnaissance Orbiter (MRO), looking for a dark patch that wasn’t in earlier photos of the same location.
If a scientist spots the signs of a crater in one of those images, it then has to be confirmed using a higher-resolution photograph taken by another MRO instrument: the High-Resolution Imaging Science Experiment (HiRISE).
This method of spotting new craters on Mars makes it easy to determine an approximate date for when each formed — if a crater wasn’t in a photo from April 2016 but is in one from June 2018, for example, the scientists know it must have formed sometime between those two dates.
By studying the characteristics of the craters whose ages they do know, the scientists can then estimate the ages of older ones. This information can improve their understanding of Mars’ history and help with the planning of new missions to the Red Planet.
The problem: this is incredibly time-consuming.
The MRO has been taking photos of the Red Planet’s surface for 15 years now, and in that time, it has snapped 112,000 lower-resolution images, with each covering hundreds of miles of the Martian surface.
To free scientists from the burden of manually analyzing all those photos, researchers trained an algorithm to scan the same images for signs of new craters on Mars — and it only needs about five seconds per picture.
Fresh craters on Mars
To train their image-analyzing AI to spot new craters on Mars, the researchers started by feeding it nearly 7,000 images from the Context Camera. Some featured fresh craters confirmed by HiRISE photos, and others didn’t.
After training, the next step was letting the algorithm analyze all of the Context Camera images.
This is just beginning. We’re looking forward to finding a lot more.
To speed it up, the researchers ran the AI on a supercomputer cluster at NASA’s Jet Propulsion Laboratory (JPL).
“It wouldn’t be possible to process over 112,000 images in a reasonable amount of time without distributing the work across many computers,” JPL computer scientist Gary Doran said in October. “The strategy is to split the problem into smaller pieces that can be solved in parallel.”
With the power of all those computers combined, the AI could scan an image in an average of just five seconds. If it flagged something that looked like a fresh crater, NASA scientists could then check it out themselves using HiRISE.
Scanning the Martian surface
In October, NASA confirmed that the AI had discovered its first fresh craters on Mars, and to date, it’s helped scientists spot dozens of new impacts in the Context Camera images.
“The data was there all the time,” JPL computer scientist Kiri Wagstaf told Wired. “It’s just that we hadn’t seen it ourselves.”
In the future, the AI might help scientists identify more craters on Mars — potentially within weeks of their formation — or even craters on other planets.
“The possibility of using machine learning to really delve into large data sets and find things that we otherwise wouldn’t have found is really exciting,” Ingrid Daubar, a planetary scientist who helped create the AI, told Wired.
“This is just beginning,” she added. “We’re looking forward to finding a lot more.”
Astronomers analyzed light data from a piece of supernova shrapnel to gain clues about where it came from.
About 2,000 light-years away from Earth, there is a star catapulting toward the edge of the Milky Way. This particular star, known as LP 40?365, is one of a unique breed of fast-moving stars — remnant pieces of massive white dwarf stars — that have survived in chunks after a gigantic stellar explosion.
“This star is moving so fast that it’s almost certainly leaving the galaxy…[it’s] moving almost two million miles an hour,” says JJ Hermes, Boston University College of Arts & Sciences assistant professor of astronomy. But why is this flying object speeding out of the Milky Way? Because it’s a piece of shrapnel from a past explosion — a cosmic event known as a supernova — that’s still being propelled forward.
“To have gone through partial detonation and still survive is very cool and unique, and it’s only in the last few years that we’ve started to think this kind of star could exist,” says Odelia Putterman, a former BU student who has worked in Hermes’ lab.
In a new paper published in The Astrophysical Journal Letters, Hermes and Putterman uncover new observations about this leftover “star shrapnel” that gives insight to other stars with similar catastrophic pasts.
Putterman and Hermes analyzed data from NASA’s Hubble Space Telescope and Transiting Exoplanet Survey Satellite (TESS), which surveys the sky and collects light information on stars near and far. By looking at various kinds of light data from both telescopes, the researchers and their collaborators found that LP 40?365 is not only being hurled out of the galaxy, but based on the brightness patterns in the data, is also rotating on its way out.
“The star is basically being slingshotted from the explosion, and we’re [observing] its rotation on its way out,” says Putterman, who is second author on the paper.
“We dug a little deeper to figure out why that star [was repeatedly] getting brighter and fainter, and the simplest explanation is that we’re seeing something at [its] surface rotate in and out of view every nine hours,” suggesting its rotation rate, Hermes says. All stars rotate — even our sun slowly rotates on its axis every 27 days. But for a star fragment that’s survived a supernova, nine hours is considered relatively slow.
Supernovas occur when a white dwarf gets too massive to support itself, eventually triggering a cosmic detonation of energy. Finding the rotation rate of a star like LP 40?365 after a supernova can lend clues into the original two-star system it came from. It’s common in the universe for stars to come in close pairs, including white dwarfs, which are highly dense stars that form toward the end of a star’s life. If one white dwarf gives too much mass to the other, the star being dumped on can self-destruct, resulting in a supernova. Supernovas are commonplace in the galaxy and can happen in many different ways, according to the researchers, but they are usually very hard to see. This makes it hard to know which star did the imploding and which star dumped too much mass onto its star partner.
Based on LP 40?365’s relatively slow rotation rate, Hermes and Putterman feel more confident that it is shrapnel from the star that self-destructed after being fed too much mass by its partner, when they were once orbiting each other at high speed. Because the stars were orbiting each other so quickly and closely, the explosion slingshotted both stars, and now we only see LP 40-365.
“This [paper] adds one more layer of knowledge into what role these stars played when the supernova occurred,” and what can happen after the explosion, Putterman says. “By understanding what’s happening with this particular star, we can start to understand what’s happening with many other similar stars that came from a similar situation.”
“These are very weird stars,” Hermes says. Stars like LP 40-365 are not only some of the fastest stars known to astronomers, but also the most metal-rich stars ever detected. Stars like our sun are composed of helium and hydrogen, but a star that has survived a supernova is primarily composed of metal material, because “what we’re seeing are the by-products of violent nuclear reactions that happen when a star blows itself up,” Hermes says, making star shrapnel like this especially fascinating to study.
Scientists find chunk of blown-apart star hurtling through Milky Way at breakneck speed
LP 40-365 will probably leave the galaxy at some point, scientists say.
Artist’s impression of a supernova ejecting a white dwarf star. (Image credit: Mark Garlick / Science Photo Library via Getty Images )
A chunk of stellar shrapnel is careering toward the edge of our Milky Way galaxy at almost 2 million mph (3.2 million kph), a new study reports.
“The star is moving so fast that it’s almost certainly leaving the galaxy,” study co-lead author J.J. Hermes, an associate professor of astronomy at Boston University, said in a statement.
The star, known as LP 40-365, currently lies about 2,000 light-years from Earth. And calling it a star may be a bit generous, actually; Hermes and his colleagues think it’s a hunk of a superdense stellar corpse called a white dwarf that was blown apart in a violent supernova explosion after gobbling up too much mass from a companion.
“To have gone through partial detonation and still survive is very cool and unique, and it’s only in the last few years that we’ve started to think this kind of star could exist,” study co-author Odelia Putterman, a former Boston University student who has worked in Hermes’ lab, said in the same statement.
The speedy star was spotted during an analysis of survey data gathered by NASA’s Hubble Space Telescope and Transiting Exoplanet Survey Satellite (TESS). The researchers noticed that LP 40-365is not only racing along but is also rotating once every nine hours as it goes.
The rotation in itself is nothing unusual, for all stars rotate; our own sun spins on its axis every 27 Earth days. However, according to researchers, a nine-hour rotational period is considered to be relatively slow for an object that went through something as catastrophic as a supernova.
It’s this sluggish rotation that implies LP 40-365 was once part of a two-star system with an unhealthy feeding habit.
According to the researchers, stars commonly orbit each other in close pairs, including highly dense white dwarfs. In such binary systems, if one white dwarf transfers too much mass to the other, the result can be a supernova — the largest explosion that takes place in space, according to NASA.
It’s usually hard to determine which star was the “donor” and which was the “eater.” But because LP 40-365’s rotation is relatively slow, the research team feels confident that the object is cosmic shrapnel from the exploded star. As the two stars orbited each other at high speeds and in close proximity, the resulting supernova likely catapulted both stars out at breakneck speed, but we’ve only been able to spot LP 40-365, according to the statement.
“This [paper] adds one more layer of knowledge into what role these stars played when the supernova occurred,” and what can happen after the explosion, Putterman said. “By understanding what’s happening with this particular star, we can start to understand what’s happening with many other similar stars that came from a similar situation.”
These supernova survivors are even more intriguing as they are metal-rich, unlike our sun, which is primarily composed of hydrogen and helium. (Astronomers consider any element heavier than hydrogen and helium a metal.)
“These are very weird stars,” Hermes said. “What we’re seeing are the byproducts of violent nuclear reactions that happen when a star blows itself up.” Strange stars like LP 40-365 are therefore fascinating targets to study, the researchers said.
NASA probe snaps ‘great conjunction’ photo of Jupiter and Saturn from the moon
Behold, the view from the Lunar Reconnaissance Orbiter!
A moon-orbiting probe got a stunning up-close view of the “great conjunction” of Jupiter and Saturn from Earth’s rocky satellite.
Jupiter and Saturn appeared closer in the night sky than they had in about 800 years during what’s known as a “great conjunction.” People all around the globe watched and photographed the planets, which looked almost like a single, bright “star” in the sky. However, us Earthlings weren’t the only ones who got a celestial show.
NASA’s Lunar Reconnaissance Orbiter (LRO), which launched in 2009 and has enough fuel to keep orbiting the moon for another six years, spotted the cosmic event all the way from the moon.
The Lunar Reconnaissance Orbiter Camera’s (LROC) Narrow Angle Camera (NAC) captured an unbelievable image of the two planets just a few hours after the pair’s point of closest separation (0.1 degrees). Now, while Jupiter and Saturn may have looked like one glowing orb to the naked eye, with the detailed view of the NAC, you can clearly resolve the individual planets. In fact, the image provides so much detail that you can even faintly see Saturn’s rings.
Here on Earth, skywatchers were able to see Jupiter’s moons with DSLR cameras and even basic telescopes, though Saturn’s rings were usually only visible with higher-powered telescopes.
When the NAC captured this image of the two planets, Jupiter was about four times brighter than Saturn, so the brightness of the original image was adjusted to make both equally visible.
While Jupiter and Saturn have a close conjunction once every 20 years, the planets haven’t appeared this close since 1623. Additionally, the planetary alignment came just a few days before Christmas, with many dubbing the bright event a “Christmas Star,” adding even more to the astronomical excitement.
Astronomers calculate that the Oort Cloud may be home to more visiting objects than objects that belong to our solar system.
In 2019, astronomers spotted something incredible in our backyard: a rogue comet from another star system. Named Borisov, the icy snowball traveled 110,000 miles per hour and marked the first and only interstellar comet ever detected by humans.
But what if these interstellar visitors — comets, meteors, asteroids and other debris from beyond our solar system — are more common than we think?
In a new study published Monday in the Monthly Notices of the Royal Astronomical Society, astronomers Amir Siraj and Avi Loeb at the Center for Astrophysics | Harvard & Smithsonian (CfA) present new calculations showing that in the Oort Cloud — a shell of debris in the farthest reaches of our solar system — interstellar objects outnumber objects belonging to our solar system.
“Before the detection of the first interstellar comet, we had no idea how many interstellar objects there were in our solar system, but theory on the formation of planetary systems suggests that there should be fewer visitors than permanent residents,” says Siraj, a concurrent undergraduate and graduate student in Harvard’s Department of Astronomy and lead author of the study. “Now we’re finding that there could be substantially more visitors.”
The calculations, made using conclusions drawn from Borisov, include significant uncertainties, Siraj points out. But even after taking these into consideration, interstellar visitors prevail over objects that are native to the solar system.
“Let’s say I watch a mile-long stretch of railroad for a day and observe one car cross it. I can say that, on that day, the observed rate of cars crossing the section of railroad was one per day per mile,” Siraj explains. “But if I have a reason to believe that the observation was not a one-off event — say, by noticing a pair of crossing gates built for cars — then I can take it a step further and begin to make statistical conclusions about the overall rate of cars crossing that stretch of railroad.”
But if there are so many interstellar visitors, why have we only ever seen one?
We just don’t have the technology to see them yet, Siraj says.
Consider, he says, that the Oort Cloud spans a region some 200 billion to 10 trillion miles away from our Sun — and unlike stars, objects in the Oort Cloud don’t produce their own light. Those two factors make debris in the outer solar system incredibly hard to see.
Senior astrophysicist Matthew Holman, who was not involved in the research, says the study results are exciting because they have implications for objects even closer than the Oort Cloud.
“These results suggest that the abundances of interstellar and Oort cloud objects are comparable closer to the Sun than Saturn. This can be tested with current and future solar system surveys,” says Holman, who is the former director of the CfA’s Minor Planet Center, which tracks comets, asteroids and other debris in the solar system.
“When looking at the asteroid data in that region, the question is: are there asteroids that really are interstellar that we just didn’t recognize before?” he asks.
Holman explains that there are some asteroids that get detected but aren’t observed or followed up on year after year. “We think they are asteroids, then we lose them without doing a detailed look.”
Loeb, study co-author and Harvard astronomy professor, adds that “interstellar objects in the planetary region of the solar system would be rare, but our results clearly show they are more common than solar system material in the dark reaches of the Oort cloud.”
Observations with next-generation technology may help confirm the team’s results.
The launch of the Vera C. Rubin Observatory, slated for 2022, will “blow previous searches for interstellar objects out of the water,” Siraj says, and hopefully help detect many more visitors like Borisov.
The Transneptunian Automated Occultation Survey (TAOS II), which is specifically designed to detect comets in the far reaches of our solar system, may also be able to detect one of these passersby. TAOS II may come online as early as this year.
The abundance of interstellar objects in the Oort Cloud suggests that much more debris is left over from the formation of planetary systems than previously thought, Siraj says.
“Our findings show that interstellar objects can place interesting constraints on planetary system formation processes, since their implied abundance requires a significant mass of material to be ejected in the form of planetesimals,” Siraj says. “Together with observational studies of protoplanetary disks and computational approaches to planet formation, the study of interstellar objects could help us unlock the secrets of how our planetary system — and others — formed.”
What’s creating these unusual signals? And why does this one repeat itself?
A photo shows the Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst Project at night. (Image credit: CHIME FRB)
One of the universe’s deep mysteries just got a lot stranger. Astrophysicists have discovered a clue that could help explain why, every once in a while, superfast bursts of radio waves flash across Earth from deep space. But the clue — a repeating 16-day pattern in one of the bursts, undermines one of the most popular theories for where the bursts are coming from.
But no one knows what causes them. Because these bursts are so rare, unusual and bright — considering that they’re visible from billions of light-years across space — physicists have tended to assume they come from a cataclysmic event, such as the collision of stars.
This repeating pattern, however, suggests that something else is going on, that there’s some sort of natural machine in the universe for pumping regular shrieks of radio energy across space.
Researchers looking at data from the Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst Project (CHIME/FRB) first spotted this FRB, known as FRB 180916.J0158+65, in 2019. In January 2020, they published a paper in the journal Nature that reanalyzed old data and found more than one burst from FRB 180916.J0158+65. They traced this FRB back to a relatively nearby spiral galaxy. What’s new in this latest paper, published Feb. 3 to the arXiv database, is the regular pattern in the bursts. The FRB, they found, goes through four-day cycles of regular activity, bleating out radio waves into space on an almost hourly basis. Then it goes into a 12-day period of silence. Sometimes the source seems to skip its usual four-day awake periods, or lets out only a single burst. CHIME/FRB is able to watch the FRB only some of the time, they noted, so it’s likely the detector misses many FRBs during the awake period.
No one knows what this pattern means, the researchers noted in a statement, but this pattern doesn’t fit neatly into any existing explanations for FRBs.
In general, patterns like this in astrophysics are often related to a spinning object or orbiting celestial bodies. Neutron stars often seem to strobe regularly from the perspective of X-ray detectors on Earth, because hot spots on their surface spin in and out of view like a lighthouse beacon. And tiny planets may dim the light of the stars they orbit everytime they pass between that star and Earth.
In other words, for astrophysics, patterns tend to indicate rotation. But no one knows if this pattern governs all FRBs or just some of them.
Dawn’s last look at the asteroid VestaCredit: NASA / JPL-Caltech / UCLA / MPS / DLR / IDAVesta is the second largest asteroid in our solar system and believed to be a proto-planet. NASA’s Dawn spacecraft visited Vesta in 2011.The mission revealed two massive impact craters and some odd troughs encircling them.
The asteroid Vesta is the second largest asteroid in the solar system’s asteroid belt, with a diameter of about 330 miles. (Ceres is the biggest.) It is the brightest asteroid up there, too, sometimes visible to the naked eye from Earth. Astronomers consider it a planetesimal because, like a mini-Earth, it has an iron core and rock in its crust and mantle.
The asteroid has long been an object of interest to star-gazers. The first book Isaac Asimov published was called Marooned off Vesta, and in 2011, the NASA spacecraft Dawn paid it a visit on its way to Ceres.
Dawn found two massive impact craters on Vesta — Rheasilvia and Veneneia — evidence of collisions large enough that they ejected about one percent of Vesta out into space. Indeed, roughly six percent of the meteorites we have found on Earth come from Vesta. Dawn also observed that there are two enormous troughs roughly around Rheasilvia and Veneneia. It has been assumed that they are somehow related to the two giant impacts.
A new study revisits this assumption and proposes a novel hypothesis about what exactly these mysterious troughs are.
Vesta’s topography, color-enhanced, from Dawn.Credit: NASA / JPL-Caltech / UCLA / MPS / DLR / IDA / PSI
If the troughs were produced by the Rheasilvia and Veneneia impacts, then they must be roughly the same age as the craters. Counting craters is one way to determine age.
“Our work used crater-counting methods to explore the relative age of the basins and troughs,” says co-author Jupiter Cheng. Since a newly formed body is free of impact craters, one can estimate its age by counting the number of craters present. While this is obviously an imprecise way of figuring out the absolute age of an asteroid, it is useful for determining the relative age of specific features. If the features are surrounded by a similar number of impacts, they are probably roughly the same age.
“Our result,” says Cheng, “shows that the troughs and basins have a similar number of the crater of various sizes [sic], indicating they share a similar age. However, the uncertainties associated with the crater counts allow for the troughs to have formed well after the impacts.”
This timeline fits with the researcher’s proposed explanation for the troughs.
It has been assumed, says Cheng, that the “troughs are fault-bounded valleys with a distinct scarp on each side that together mark the down-drop (sliding) of a block of rock.”
However, there is a problem with this theory. It is based on the way rocks and debris behave under the force of gravity on Earth; Vesta’s gravitational pull is far less. Indeed, Dawn found Vesta’s gravity consistent with an iron core having a 140-mile diameter; the Earth’s, by comparison, is about 2,165 miles in diameter.
Cheng notes that “rock can also crack apart and form such troughs, an origin that has not been considered before. Our calculations also show that Vesta’s gravity is not enough to induce surrounding stresses favorable for sliding to occur at shallow depths. Instead, the physics shows that rocks there are favored to crack apart.”
Cheng summarizes, “Taken all together, the overall project provides alternatives to the previously proposed trough origin and geological history of Vesta, results that are also important for understanding similar landforms on other small planetary bodies elsewhere in the solar system.”
So while still consistent with the prevailing theory that the impacts resulted in the troughs, the researchers suggest that they did not cause landslides on Vesta. The impacts cracked it.
Voyager 1 image of Jupiter’s moon Callisto from a distance of 350,000 km. The large ‘bulls-eye’ at the top is believed to be an impact basin formed early in Callisto’s history. The bright center of the basin is about 600 km across and the outer ring is about 2,600 km across. (Image credit: NASA/NSSDC Photo Gallery)
Callisto is a large moon orbiting Jupiter. It has an ancient, cratered surface, indicating that geological processes could be dead. However, it may also hold an underground ocean. It’s unclear if the ocean could have life in it because the surface is so old. It will take more observation of this large moon to be absolutely sure.
The moon has been a subject of several flybys, including the long-running Galileo mission at Jupiter in the 1990s and 2000s. An upcoming mission called JUICE (Jupiter Icy Moon Explorer) will focus on three icy Jupiter moons, including Callisto, to get more information about its environment. JUICE is expected to arrive in 2030.
Several icy moons of the solar system have been a focus of exploration in recent years because of their potential for holding life. The Cassini spacecraft, which orbited Saturn from 2004 to 2017, uncovered extensive evidence of geysers at its moon, Enceladus. Other icy moons include Triton (at Neptune, imaged by Voyager 2) and Europa (another icy moon of Jupiter.) In general, these moons maintain liquid oceans because of the gravitational tug from their large giant planets.
When Galileo turned his telescope to Jupiter on Jan. 7, 1610, what he saw surprised everybody. The planet was not alone; it had four moons circling it. At the time, it was believed that the Earth was the only planet with a moon. For two centuries Jupiter’s moons were (as a group) named after the Medicis, a powerful Italian political family, according to NASA. Individually they were called Jupiter I, II, III and IV, with “IV” referring to what we now call Callisto.
The discovery had not only astronomical, but also religious implications. At the time, the Catholic Church supported the idea that everything orbited the Earth, an idea put forth in ancient times by Aristotle and Ptolemy. Galileo’s observations of Jupiter’s moons — as well as noticing that Venus went through “phases” similar to our own moon — gave compelling evidence that not everything revolved around the Earth.
As telescopic observations improved, however, a new view of the universe emerged. The moons and the planets were not unchanging and perfect; for example, mountains seen on the moon showed that geological processes happened elsewhere. Also, all planets revolved around the sun. Over time, moons around other planets were discovered — and additional moons found around Jupiter. The Medici moons were renamed Io, Europa, Ganymede and Callisto to avoid confusion by the mid-1800s.
Age: Callisto is about 4.5 billion years old, about the same age as Jupiter. It is the most heavily cratered object in the solar system, according to NASA. There is hardly any geologic activity on its surface. The surface has not changed much since initial impacts molded its surface 4 billion years ago.
Distance from Jupiter: It is the outermost of the Galilean moons. Callisto orbits Jupiter at a distance of about 1,168,000 miles (1,880,000 kilometers). It takes the moon about seven Earth-days to make one complete orbit of the planet. It also experiences fewer tidal influences than the other Galilean moons because it orbits beyond Jupiter’s main radiation belt. Callisto is tidally locked, so the same side always faces Jupiter.
Size: At 3,000 miles (4,800 km) in diameter, Callisto is roughly the same size as Mercury. It is the third largest moon in the solar system, after Ganymede and Titan. (Earth’s moon is fifth largest, following Io.)
Temperature: The mean surface temperature of Callisto is minus 218.47 degrees Fahrenheit (minus 139.2 Celsius).
While telescopes improved substantially by the Space Age of the 1960s, still little was known about Callisto, according to the 2004 book “Jupiter: The Planet, Satellites and Magnetosphere” (Cambridge, 2007). From what astronomers could tell, the surface looked relatively featureless compared with Io and Ganymede. Callisto also had low reflectivity (albedo) and was known to have a low density, but astronomers saw no evidence of water emissions. This led them to conclude that Callisto had a rocky surface.
Pioneer 10 and Pioneer 11 each flew by Jupiter and its moons in the early 1970s, but these missions didn’t give much new information on Callisto beyond what Earth-based telescopes showed. It was the Voyager missions of the late 1970s that really showed us a different picture of the moon. Callisto’s density and temperature were refined, and images of the surface showed features as small as 1 kilometer per pixel — in other words, a resolution small enough to spot impact craters. In fact, Callisto was very heavily cratered compared with the other moons, the authors wrote. “Some dismissed Callisto as the most boring object of its size in the solar system,” they added.
More close-up observations required a wait until 1996, when the Galileo spacecraft commenced the first of 12 flybys of the moon. Galileo’s repeated flybys and higher resolution revealed much more information about Callisto than before. More of the surface was mapped, a thin carbon dioxide atmosphere was discovered, and evidence of a subsurface ocean was uncovered.
Arguments for an ocean came from two pieces of evidence, according to NASA. First, scientists saw regular fluctuations of Callisto’s magnetic field as the moon circled Jupiter, which implied there were electrical currents within the moon stimulated by the planet’s magnetic field. That current had to conduct from somewhere, which led to the second piece: due to the rocky surface and thin atmosphere, a likely explanation would be a salty ocean under the moon’s surface.Advertisement
In 2018, examinations of archival images taken by the Hubble Space Telescope in 2007 showed Callisto’s effect on auroral bursts in Jupiter’s atmosphere. Jupiter generates auroras on its own, but some of the phenomena come through interactions with its four largest moons: Europa, Io, Ganymede and Callisto. The signatures of the other moons were previously spotted in Jupiter’s atmosphere, but this new research represented the first time that Callisto’s effect was found.
Callisto and the other Galilean moons may have formed with the assistance of Saturn. A computer model released in 2018 suggested that as Saturn’s core grew, its gravitational influence moved planetesimals (baby planets) toward the inner solar system. This process might have provided enough stuff to form the four Galilean moons.
If Callisto is habitable — and how it formed that way — are among the outstanding questions that the JUICE mission will start studying. JUICE is slated to launch toward Jupiter in 2022 and work at the planet for at least three years, between 2030 and 2033.
JUICE will focus on the moon Ganymede, but its science objectives for Callisto will be similar. This includes looking for ocean layers or water reservoirs, mapping the surface, looking at the atmosphere and figuring out what Callisto’s interior looks like.
There are eight known planets in the solar system (ever since Pluto was booted from the club), but for a while, there has been some evidence that there might be one more. A hypothetical Planet 9 lurking on the outer edge of our solar system. So far this world has eluded discovery, but a new study has pinned down where it should be.
The evidence for Planet 9 comes from its gravitational pull on other bodies. If the planet exists, its gravity will affect the orbits of other planets. So if something seems to be tugging on a planet, just do a bit of math to find the source. This is how Neptune was discovered, when John Couch Adams and Urbain Le Verrier noticed independently that Uranus seemed to be tugged by an unseen planet.
In the case of Planet 9, we don’t have any gravitational effect on a planet. What we do see is an odd clustering of small icy bodies in the outer solar system known as Kuiper belt objects (KBOs). If there were no planet beyond the Kuiper belt, you would expect the orbits of KBOs to be randomly oriented within the orbital plane of the solar system. But instead, we see lots of KBO orbits are clustered in the same orientation. It’s possible that this is just due to random chance, but that isn’t likely.
Back in 2016, the authors looked at the statistical distribution of KBOs and concluded the clustering was caused by an undetected outer planet. Based on their calculations, this world has a mass of 5 Earths and is about 10 times more distant from the Sun than Neptune. The paper even calculated a broad region of the sky where the planet might be. But searches turned up nothing. This led some to conclude the planet doesn’t exist. Orbital oddness doesn’t prove a planet exists. Just ask Planet Vulcan. Others went so far as to argue Planet 9 does exist, but we can’t see it because it’s a primordial black hole.
This new study reexamines the original work in light of some of the criticism it received. One big criticism is that outer solar system bodies are difficult to find, so we look for them where it’s convenient. The clustering effect we see could just be due to biased data. Taking observational bias into effect, the authors find the clustering is still statistically unusual. There’s only a 0.4% chance of it being a fluke. When they recalculated the likely orbit of Planet 9, they were able to better localize where to look.
One interesting aspect of the study is that the newly calculated orbit puts Planet 9 closer to the Sun than originally thought. This is odd, because if it is closer then we should have already found it. The authors argue that observations thus far have ruled out the closest options for Planet 9, which helps narrow down its possible location even further. If the planet exists, it should be detectable by the Vera Rubin Observatory in the near future.
This study isn’t conclusive, and many astronomers still argue that Planet 9 doesn’t exist. But this study makes it clear that we won’t have to argue about it for much longer. Either it will be discovered soon, or observations will rule it out as an explanation for the KBO clustering effect.
Mysterious ‘Planet Nine’ Is Probably 5 to 10 Times the Size of Earth
There could be a planet hiding out on the distant frontiers of our solar system. And astronomers have published new details about what it probably looks like, if it really exists.
Planet 9, according to a new paper published online Feb. 10 in the journal Physics Reports, is probably five to 10 times the mass of Earth. And it probably travels along an elongated orbit that peaks at 400 times Earth’s distance from the sun. That orbit is also likely 15 to 25 degrees off the main orbital plain of our solar system where most planets orbit.
The existence of Planet Nine, as Live Science sister site Space.com previously reported, is an idea that’s become popular among astronomers ever since it was first seriously proposed back in 2014. Researchers suspect the planet’s existence because of patterns of objects in the Kuiper Belt, a ring of debris in the outer solar system. Those objects tend to clump together in ways that suggest that gravity from something big out there is tugging on them.
Strongly suspecting that the dark planet exists isn’t the same thing as knowing it’s real, though. The good news is that this new research suggests that Planet Nine is significantly nearer-by than previously thought. But astronomers still have a lot of space in which to search for it.
The authors of the Physics Reports paper did raise, however, the possibility that there’s no planet out there at all. They added that however strong the current evidence is, that chance should be “taken seriously.”
The likeliest alternative explanation is that humanity’s picture of the Kuiper Belt is incomplete and that the objects only appear to cluster because of some bias in efforts to detect them. It’s also possible, the authors suggested, that the clustering results from the “self-gravity” of the Kuiper Belt acting on its own objects and does not arise from not some hidden planet’s tug.
Still, astronomers have become more convinced by the evidence for Planet Nine in recent years. And now they’re making significant progress toward pinpointing it out in space.
Undersea cables would be hit especially hard by a coronal mass ejection.
Scientists have known for decades that an extreme solar storm, or coronal mass ejection, could damage electrical grids and potentially cause prolonged blackouts. The repercussions would be felt everywhere from global supply chains and transportation to Internet and GPS access. Less examined until now, though, is the impact such a solar emission could have on Internet infrastructure specifically. New research shows that the failures could be catastrophic, particularly for the undersea cables that underpin the global Internet.
At the SIGCOMM 2021 data communication conference on Thursday, Sangeetha Abdu Jyothi of the University of California, Irvine presented “Solar Superstorms: Planning for an Internet Apocalypse,” an examination of the damage a fast-moving cloud of magnetized solar particles could cause the global Internet. Abdu Jyothi’s research points out an additional nuance to a blackout-causing solar storm: the scenario where even if power returns in hours or days, mass Internet outages persist.
There’s some good news upfront. Abdu Jyothi found that local and regional Internet infrastructure would be at low risk of damage even in a massive solar storm, because optical fiber itself isn’t affected by geomagnetically induced currents. Short cable spans are also grounded very regularly. But for long undersea cables that connect continents, the risks are much greater. A solar storm that disrupted a number of these cables around the world could cause a massive loss of connectivity by cutting countries off at the source, even while leaving local infrastructure intact. It would be like cutting flow to an apartment building because of a water main break.
“What really got me thinking about this is that with the pandemic we saw how unprepared the world was. There was no protocol to deal with it effectively and it’s the same with Internet resilience,” Abdu Jyothi told WIRED ahead of her talk. “Our infrastructure is not prepared for a large-scale solar event. We have very limited understanding of what the extent of the damage would be.”Advertisement
That information gap mostly comes from lack of data. Severe solar storms are so rare that there are only three main examples to go off of in recent history. Large events in 1859 and 1921 demonstrated that geomagnetic disturbances can disrupt electrical infrastructure and communication lines like telegraph wires. During the massive 1859 “Carrington Event,” compass needles swung wildly and unpredictably, and the aurora borealis was visible at the equator in Colombia. But those geomagnetic disturbances occurred before modern electric grids were established. A moderate-severity solar storm in 1989 knocked out Hydro-Québec’s grid and caused a nine-hour blackout in northeast Canada, but that too occurred before the rise of modern Internet infrastructure.
Though they don’t happen often, coronal mass ejections are a real threat to Internet resilience, says Abdu Jyothi. And after three decades of low solar storm activity, she and other researchers point out that the probability of another incident is rising.
Undersea Internet cables are potentially susceptible to solar storm damage for a few reasons. To shepherd data across oceans intact, cables are fitted with repeaters at intervals of roughly 50 to 150 kilometers depending on the cable. These devices amplify the optical signal, making sure that nothing gets lost in transit, like a relay throw in baseball. While fiber optic cable isn’t directly vulnerable to disruption by geomagnetically induced currents, the electronic internals of repeaters are—and enough repeater failures will render an entire undersea cable inoperable. Additionally, undersea cables are only grounded at extended intervals hundreds or thousands of kilometers apart, which leaves vulnerable components like repeaters more exposed to geomagnetically induced currents. The composition of the sea floor also varies, possibly making some grounding points more effective than others.
On top of all of this, a major solar storm could also knock out any equipment that orbits the Earth that enables services like satellite Internet and global positioning.
“There are no models currently available of how this could play out,” Abdu Jyothi says. “We have more understanding of how these storms would impact power systems, but that’s all on land. In the ocean it’s even more difficult to predict.”
Coronal mass ejections tend to have more impact at higher latitudes, closer to the Earth’s magnetic poles. That’s why Abdu Jyothi worries more about cables in some regions than others. She found, for example, that Asia faces less risk, because Singapore acts as a hub for many undersea cables in the region and is at the equator. Many cables in that region are also shorter, because they branch in many directions from that hub rather than being set up as one continuous span. Cables that cross the Atlantic and Pacific oceans at high latitude would be at greater risk from even moderate storms.
The global Internet is built for resilience. If one pathway isn’t available, traffic reroutes across other paths, a property that could potentially keep connectivity up, even at reduced speeds, in the event of a solar storm. But enough damage to these vital arteries would start to destabilize the network. And depending on where the cable outages occur, Abdu Jyothi says that foundational data routing systems like the Border Gateway Protocol and Domain Name System could start to malfunction, creating knock-on outages. It’s the Internet version of the traffic jams that would happen if road signs disappeared and traffic lights went out at busy intersections across a major city.
North America and some other regions have minimum standards and procedures for grid operators related to solar storm preparedness. And Thomas Overbye, director of the Smart Grid Center at Texas A&M University, says that grid operators have made some progress mitigating the risk over the past 10 years. But he emphasizes that since geomagnetic disturbances are so rare and relatively unstudied, other threats from things like extreme weather events or cyberattacks are increasingly taking priority.
“Part of the problem is we just don’t have a lot of experience with the storms,” Overbye says. “There are some people who think a geomagnetic disturbance would be a catastrophic scenario and there are others who think it would be less of a major event. I’m kind of in the middle. I think it’s something that we certainly as an industry want to be prepared for and I’ve been working to develop tools that assess risk. But yet there are a lot of other things going on in the industry that are important, too.”
The Internet infrastructure side contains even more unknowns. Abdu Jyothi emphasizes that her study is just the beginning of much more extensive interdisciplinary research and modeling that needs to be done to fully understand the scale of the threat. While severe solar storms are extremely rare, the stakes are perilously high. A prolonged global connectivity outage of that scale would impact nearly every industry and person on Earth.