The asteroid 2024 YR4, discovered at the end of 2024, initially appeared to be on a collision course with Earth. However, its revised trajectory now draws attention to another possible target: the moon. The chance of YR4 hitting Earth changed with every new observation, peaking at 3.1% in February. NASA’s latest observations have improved astronomers’ knowledge of where it will be in seven years by almost 20%.
The impact would be a once-in-a-lifetime event for humanity to witness, but it could also send fine-grained lunar material hurtling toward our planet. While Earth wouldn’t face any significant physical danger should the asteroid strike the moon, there is a chance that any astronauts or infrastructure on the lunar surface at that time could be at risk. Satellites orbiting our planet that we depend on to keep vital aspects of life running smoothly could also be at risk.
Asteroids that might be headed for the moon could redefine the range of risks the field addresses, expanding the purview of the work to include monitoring asteroids that might be headed for the moon as well. Researchers are assessing the chaos a potential YR4 lunar impact could create and whether anything can be done to mitigate it.
The newly approved program will buy decision makers two extra years to prepare, though most likely to relax, as there is an 80% chance of ruling out impact. Additionally, asteroids that have potential to affect the moon could become objects of even more intense study in the future.
