Asteroids the size of Apophis are far fewer in number and so do not pass this close to Earth as often but Apophis is a also representative of about 2,000 currently known Potentially Hazardous Asteroids.
At closest approach, Apophis will be over the Atlantic Ocean | Photo for representation
- Asteroid called 99942 Apophis will cruise by Earth, about 31,000 km above the surface
- That’s within distance that some of our spacecraft that orbit Earth
- A team of astronomers discovered Apophis in June 2004
On April 13, 2029, a speck of light will streak across the sky getting brighter and faster.
At one point it will travel more than the width of the full Moon within a minute and it will get as bright as the stars in the Little Dipper (Ursa Minor is colloquially known in the US as the Little Dipper).
But, it won’t be a satellite or an airplane.
Then what it may be? Well, it will be a 340-metre-wide near-Earth asteroid.
The asteroid called 99942 Apophis will cruise harmlessly by Earth, about 31,000 km above the surface. That’s within the distance that some of our spacecraft that orbit Earth.
The international asteroid research community couldn’t be more excited.
THE ASTEROID’S CLOSE APPROACH
This week at the 2019 Planetary Defense Conference in College Park, Maryland, scientists are gathering to discuss observation plans and science opportunities for the celestial event still a decade away.
During a session on April 30, scientists will discuss everything from how to observe the event to hypothetical missions we could send out to the asteroid.
“The Apophis close approach in 2029 will be an incredible opportunity for science,” Marina Brozovic, a radar scientist at Nasa’s Jet Propulsion Laboratory in Pasadena, California, who works on radar observations of near-Earth objects (NEOs), said.
“We’ll observe the asteroid with both optical and radar telescopes. With radar observations, we might be able to see surface details that are only a few meters in size,” Marina Brozovic said.
WATCH | Apophis asteroid and Earth at closest approach
It’s rare for an asteroid of this size to pass by the Earth so close. Although scientists have spotted small asteroids, on the order of 5-10 metres, flying by Earth at a similar distance, asteroids the size of Apophis are far fewer in number and so do not pass this close to Earth as often.ADVERTISEMENT
The asteroid, looking like a moving star-like point of light, will first become visible to the naked eye in the night sky over the southern hemisphere, flying above Earth from the east coast to the west coast of Australia. It will be mid-morning on the East Coast of the United States when Apophis is above Australia. It will then cross the Indian Ocean, and by the afternoon in the eastern US it will have crossed the equator, still moving west, above Africa.
At closest approach, Apophis will be over the Atlantic Ocean and it will move so fast that it will cross the Atlantic in just an hour.Small asteroid was caught in process of spinning so fast it’s throwing off material, according to new data from Nasa’s Hubble Space Telescope and other observatories | Photo via Nasa
APOPHIS AND CHANCES OF IT IMPACTING EARTH
A team of astronomers discovered Apophis in June 2004.
The observations caused quite a stir – initial orbital calculations revealed that the asteroid had a 2.7 per cent chance of impacting Earth in 2029.
Fortunately, additional observations refined the orbit and completely ruled out that possibility.
Current calculations show that Apophis still has a small chance of impacting Earth, less than 1 in 1,00,000 many decades from now, but future measurements of its position can be expected to rule out any possible impacts.
Davide Farnocchia, an astronomer at JPL’s Center for Near Earth Objects Studies (CNEOS), who is co-chairing the April 30 session on Apophis with Brozovicm, said, “We already know that the close encounter with Earth will change Apophis’ orbit, but our models also show the close approach could change the way this asteroid spins, and it is possible that there will be some surface changes, like small avalanches.”
“Apophis is a representative of about 2,000 currently known Potentially Hazardous Asteroids (PHAs),” Paul Chodas, director of CNEOS, said. “By observing Apophis during its 2029 flyby, we will gain important scientific knowledge that could one day be used for planetary defense.”
(Inputs from Nasa)