Asteroid 2024 YR4 might smash into the moon

Earlier this year, astronomers alerted the world to a startling possibility: based on initial calculations, it appeared that a recently discovered asteroid known as 2024 YR4 had a not-zero chance of colliding with Earth in 2032. At 174â220 feet wide, the space rock has the potential to destroy a sizable city in less than a decadeâs time. In this case, however, ânot-zeroâ never amounted to anything higher than a three percent probability. And after gathering additional information from an array of terrestrial observatories as well as the James Webb Space Telescope, experts concluded in March that 2024 YR4 didnât pose any direct threat to the planet.
But just because Earth was spared doesnât mean our moon is safe. Based on the most recent calculations, the chance that the asteroid has a 2032 date with the lunar surface is higher than it ever was for us.
âThe probability that asteroid 2024 YR4 will strike the Moon on 22 December 2032 is now approximately 4 percent, and this probability was still slowly rising as the asteroid faded out of view,â the European Space Agency said in its most recent update.
Okay, so itâs not that much more likely than 2024 YR4âs highest probability for Earth. But a 96-percent likelihood of missing the moon leaves room for the space rock to defy the odds. Astronomers will now need to wait until its orbit sends it around the sun in mid-2028 to begin conducting further observations.
So what happens if 2024 YR4 really does collide with the moon? Thatâs a great questionâone that even the experts canât answer at the moment.
âNo one knows what the exact effects would be,â admitted ESA Planetary Defense Office director Richard Moissl. âIt is a very rare event for an asteroid this large to impact the Moonâand it is rarer still that we know about it in advance.â
Moissl added the collision âwould certainly leave a new crater on the surface,â but itâs not currently possible to accurately predict how much material would eject into space, and whether Earthâs gravitational pull would catch any of it. That said, there isnât a major worry that an asteroid of 2024 YRâs size would result in lunar armageddon. Moissl also explained that while the impact would likely be visible from Earth, astronomers remain âexcited by the prospect of observing and analyzing it.â
If youâre still uneasy about errant asteroids hurtling towards us, take comfort in knowing that international space agencies are working to improve our early detection capabilities and plan for worst-case scenarios. The ESA, for example, is currently planning to launch its Near-Earth Object Mission in the Infrared (NEOMIR) satellite in the early 2030s. NEOMIR is designed to position itself at the first Sun-Earth Lagrange Point, one of five locations where the planetâs gravitational forces and the satelliteâs orbit interact to allow for a stable observation point. Once there, the array will be able to scan for unknown asteroids larger than 197-feet-wide that are potentially en route to Earth. This will provide governments and agencies much more time to identify, analyze, and plan for space emergencies.
âNEOMIR would have detected asteroid 2024 YR4 about a month earlier than ground-based telescopes did,â Moissl explained. âThis would have given astronomers more time to study the asteroidâs trajectory and allowed them to much sooner rule out any chance of Earth impact in 2032.â