When it returns in 2068, the asteroid Apophis will have virtually no chance of touching Earth.
The 370-meter (1,210-foot) piece of space rock will pose no danger for at least another century, resulting in its removal from ESA's Hazard List and Sentinel Impact Hazard Table. from NASA.
With the help of radar investigations and recent optical observations, the risk in the orbit of Apophis has been decreased from hundreds of kilometers to a few kilometers by 2029. he said. Said astronomer Davide Farnocchia of the Center for Near-Earth Object Studies at NASA.
Awareness of its significantly improved position in 2029 gives more confidence in their future movement, so we can now exclude Apophis from the danger file.
Apophis was first discovered in 2004, and initial projections suggested that the asteroid had a worrying 2.7% chance of hitting Earth by 2029. Although this was quickly ruled out, Apophis has a close approach to Earth about every eight years; as its orbit was challenging to observe and characterize, the possibility of impact at a later date remained undefined.
Gradually, over the 17 years that astronomers have observed Apophis, his path through space has become more apparent.
Last year, the biggest threat was determined to be near the asteroid in 2068. Farnocchia and his colleague David Tholen measured the Yarkovsky effect, the heating on the Sun side. Of the asteroid that generates a small amount of thrust - and found that it generates 170 meters of drift per year.
The other big potential problem affecting the asteroid's trajectory is the flyby of 2029. According to projections, Apophis will fly over the Earth at a distance of only 38,000 kilometers - about ten times closer than the Moon. At this proximity, the Earth's gravity will alter the orbit of the asteroid, probably causing it closer to the route of collision.
With these two influences in mind, astronomers have recalculated Apophis' path projection. The chance of impact in 2068 remained. It was only one in 150,000, but it's still a concern, given the damage it could cause.
Now more information has been attached to the calculation. The last flyby of the asteroid was just a few weeks ago - on March 6, 2021, Apophis approached within 10 million miles of Earth.
It was visible in the sky, and astronomers watched it closely; then, the March 6 flyby allowed scientists to reduce its location to an exact distance of 150 meters.
In turn, the discovery allowed the projections to be further refined, and we are now officially safe from Apophis for a very long time. Considering the asteroid has been on the Sentinels Risk List and Impact Risk Table since its discovery, this is a great relief.
When Apophis passes in 2029, it will provide scientists with an excellent opportunity to study its size, shape, and speed of rotation without the threat of disaster also looming. It will be the last such opportunity for a while - after 2029, its "close approaches" will become increasingly distant.
Farnocchia said When I started working with asteroids after college, Apophis was a kid going to a dangerous asteroid.
There is a certain sense of satisfaction in seeing it removed from the threat list, and we look forward to the science that we can uncover when it comes close to closing in 2029.