Discovered at the very end of 2024, asteroid 2024 YR4 became the greatest threat to Earth in the history of asteroid hazard observation. It was detected on a trajectory leaving Earth, so data on the orbit and the object itself were incomplete. Scientists gradually collected more data to calculate the orbit of 2024 YR4. As the parameters were refined, the asteroid was deemed harmless to Earth, but the possibility of its collision with the Moon appeared. And now this threat has grown.
An artist’s impression of asteroid 2024 YR4. Image Credit: W. M. Keck Observatory/Adam Makarenko
In May, NASA’s James Webb Space Telescope observed asteroid 2024 YR4 for the last time before it finally disappeared from view in space. A new set of data improved the accuracy of its likely orbit around the Sun by 20 percent, making it possible to reassess the likelihood of the object colliding with the Moon when it makes its closest approach to both the Moon and Earth on December 22, 2032.
The previous estimate suggested a 3.8% chance of 2024 YR4 hitting the Moon. Following the May observations, NASA increased this probability to 4.8%. The reliability of the calculations, we recall, was also increased by 20%. This is still a small chance for the asteroid to collide with the Earth’s natural satellite.
The yellow dots show the likely position of the asteroid on December 22, 2032 (the shorter strip represents the latest observations). Image credit: NASA
The fall of such a celestial body on the Moon, and 2024 YR4 is no more than 70 meters in diameter, will not change its orbit and does not pose a threat to the Earth. But if a collision occurs, then scientists will have a chance to conduct seismic sounding of the Moon due to nature itself. It can be expected that if the probability of 2024 YR4 meeting the Moon is more or less high, a station with seismic sensors will be sent to the Moon. Data on the object’s orbit can be established with maximum accuracy during its next passage near the Earth, which is expected in 2028.