Asteroid 2021 SG, which flew past Earth undetected on September 16, would have been spotted by an upcoming telescope used to detect such dangerous space rocks, NASA has insisted.
Known as the Near-Earth Object Surveyor space telescope (NEO Surveyor), the craft ‘probably’ would have spotted the asteroid on a different part of its orbit and earlier in its trajectory towards Earth, Paul Chodas, director of NASA’s Center for Near-Earth Object Studies (CNEOS), told DailyMail.com.
Asteroid 2021 SG whizzed past Earth at 153,000 miles on September 16, a distance of approximately half that of the moon. It was not detected until September 17.
This space rock has a diameter between 138 and 308 feet, or larger than a football field and roughly the same size as the State of Liberty.
‘Because of its far greater sensitivity over current asteroid surveys, NEO Surveyor probably would have detected this asteroid on a different part of the asteroid’s orbit, when the asteroid was farther away from the sun direction,’ Chodas said in an email.
Asteroid 2021 SG would have been detected by NASA’s Near-Earth Object Surveyor space telescope, the agency insists
Asteroid 2021 SG’s diameter is between 138 and 308 feet, larger than a football field and roughly the size of the State of Liberty
There are more than 26,000 near-Earth asteroids, according to NASA , though only about 10,000 of them are larger than 140 meters in size
There are more than 26,000 near-Earth asteroids, according to NASA, though only about 10,000 of them are larger than 140 meters (450 ft) in size.
Though it passed Earth within 0.05 astronomical units (AU), asteroid 2021 SG is smaller than the 460 feet in diameter that is needed for it to be considered ‘potentially hazardous,’ according to NASA.
Nonetheless, it is four times larger than the space rock that disintegrated over Chelyabinsk, Russia, on February 15, 2013.
That rock resulted in 1,500 people being injured and caused a shock wave that broke windows in six Russian cities.
The asteroid was not initially detected because it follows a ‘very eccentric orbit’ that extends from Mercury’s orbit into the asteroid belt, past the orbit of Mars
Chodas said 2021 SG was not initially detected because it follows a ‘very eccentric orbit’ that extends from Mercury’s orbit into the asteroid belt, past the orbit of Mars.
‘Over the last few months it has been on the outbound leg of its orbit, and it approached the Earth last week from the general direction of the Sun,’ Chodas added.
‘This asteroid was positioned in the daytime sky as it approached Earth. Once it passed by, however, it transitioned into the nighttime sky, became easily visible to our asteroid surveys, and was promptly detected.’
Asteroid 2021 SG was also flying past Earth at speeds of more than 53,000mph, according to EarthSky.org.
If it had entered Earth’s atmosphere, it would have produced a ‘huge, very impressive meteor,’ the organization noted, adding its closest approach was to Canada and Greenland.
Henceforth, it had entered the atmosphere, it likely would have resulted in significant destruction, given that Canada has a population of over 37 million.
The NEO surveyor spacecraft is scheduled to launch in 2026.
It will be positioned between the Earth and sun to better spot space rocks – such as 2021 SG – that right now can not be spotted because of their positions in space.
Astronomers are hunting for asteroids larger than 450ft as they can cause ‘catastrophic damage’
Researchers have discovered most of the asteroids that are about a kilometers in size, but are now on the hunt for those that are about 459ft (140m) – as they could cause catastrophic damage.
Although nobody knows when the next big impact will occur, scientists have found themselves under pressure to predict – and intercept – its arrival.
Artist’s impression pictured
‘Sooner or later we will get… a minor or major impact,’ said Rolf Densing, who heads the European Space Operations Centre (ESOC) in Darmstadt
It may not happen in our lifetime, he said, but ‘the risk that Earth will get hit in a devastating event one day is very high.’
‘For now, there is little we can do.’
Source: AFP