
Asteroid 2024 YR4 may hit the moon
MARK GARLICK/SCIENCE PHOTO LIBRARY
Astronomers are facing a critical decision regarding asteroid 2024 YR4, which poses a potential threat of colliding with the moon in 2032. With a small observing window opening in February through the James Webb Space Telescope, there is a chance that the risk of impact could rise to over 30%, putting satellites and future lunar infrastructure in jeopardy.
Initially discovered at the end of the previous year, 2024 YR4 was identified as having the highest likelihood of impacting Earth among all known asteroids. While the risk of an Earth collision has been minimized, there remains a 4% probability of the asteroid striking the moon, which could endanger numerous satellites orbiting the planet.
Despite the heightened risk posed by this asteroid, global space agencies have not yet taken action to mitigate the potential impact. NASA researchers have contemplated various deflection strategies, such as detonating a nuclear bomb near the asteroid, but no concrete plans have been put in place.
2024 YR4 has currently moved out of Earth’s telescope range, making it challenging to gather additional data on its trajectory until it reemerges in 2028. However, there is a glimmer of hope as the James Webb Space Telescope is expected to offer a brief opportunity to observe the asteroid in February 2026, providing a crucial window to evaluate the need for a deflection mission.
The unique orbit and sensitivity of the JWST enable it to view 2024 YR4 when ground-based telescopes cannot, although the observation will still be complex due to the asteroid’s faint appearance. Subsequent observations in 2027 will offer further insight into the potential collision risk, allowing for informed decision-making regarding a deflection mission.
While the possibility of a lunar impact raises questions about planetary defense extending to the moon, different agencies may have varying responses based on their priorities. Richard Moissl from the European Space Agency indicates that while no deflection missions are currently budgeted for this year, plans may change depending on the outcome of observations in the following year.
The looming threat of asteroid 2024 YR4 underscores the importance of proactive measures to safeguard critical infrastructure in space, highlighting the need for international collaboration and swift decision-making in the face of potential cosmic hazards.

