A huge asteroid called 99942 Apophis, nicknamed the "God of Chaos", has been reassessed by scientists, raising worries it might collide with Earth. Apophis, which was discovered in 2004, was once thought to have a 2.7 per cent chance of hitting Earth in 2029. Later, the American space agency, the National Aeronautics and Space Administration (NASA), in a study released in September last year, said Apophis won't impact Earth in 2029 or 2036. However, the asteroid's new path has led to fresh concerns about future risks.
Will the 'God Of Chaos' asteroid hit Earth?
Recent research by Canadian scientist Paul Wiegert has brought back discussions about the potential danger. Wiegert found that while Apophis will pass close to Earth, its path could change if it hits another small object in space. Wiegert estimates that the chance of such an event changing the asteroid's course toward Earth is about one in two billion.
According to an analysis published in The Mirror US, Wiegert ascribes that for Apophis to change its trajectory, a smaller object estimated at least 3.4 meters must crash with the asteroid at a pace greater than 510 meters per second. Further, the researcher estimates that even if the asteroid’s path was shifted negligibly, the possibility of it being diverted toward the "Blue Planet" is extremely low, at only 5 per cent.
What does NASA say in its analysis?
Asteroid 99942 Apophis is a near-Earth object (NEO) roughly 1,100 feet (335 meters) wide. When Apophis was first discovered in 2004, it was considered one of the most dangerous asteroids with the potential to hit Earth. However, as astronomers tracked its movements and refined its orbit, this assessment changed.
A radar observation campaign in March 2021, along with precise orbital analysis, showed that Apophis poses no risk of impacting Earth for at least the next century.
Initially, Apophis was feared for a close approach to Earth in 2029, and there were concerns about another close pass in 2036. However, additional observations ruled out the risk of impact in both of those years. Until March 2021, there was still a small chance of impact in 2068.
WATCH: Animation shows the orbital trajectory of asteroid Apophis as it zooms safely past Earth on April 13, 2029
“A 2068 impact is not in the realm of possibility anymore, and our calculations don’t show any impact risk for at least the next 100 years,” said Davide Farnocchia of NASA’s Center for Near-Earth Object Studies (CNEOS), which is managed by NASA’s Jet Propulsion Laboratory in Southern California.
"With the support of recent optical observations and additional radar observations, the uncertainty in Apophis’ orbit has collapsed from hundreds of kilometres to just a handful of kilometres when projected to 2029. This greatly improved knowledge of its position in 2029 provides more certainty of its future motion, so we can now remove Apophis from the risk list."
Possibility of collision
To refine their calculations for Apophis in 2021, astronomers used the 70-metre radio antenna at the Deep Space Network’s Goldstone Deep Space Communications Complex near Barstow, California, to track its motion with high precision, according to NASA.
"Although Apophis made a recent close approach with Earth, it was still nearly 17 million kilometres away. Even so, we were able to acquire incredibly precise information about its distance to an accuracy of about 150 meters," said JPL scientist Marina Brozovic, who led the radar campaign. "This campaign not only helped us rule out any impact risk, it set us up for a wonderful science opportunity," added the scientist.
During a distant flyby of Earth around March 5, 2021, astronomers used powerful radar to precisely measure Apophis's orbit, allowing them to confidently dismiss any impact risk for 2068 and far beyond.
(With inputs from agency)
