Analysis: Possible asteroid impact on the moon could still be prevented

If humanity were to decide to prevent an impact of the asteroid 2024 YR₄ on the moon, which is still not ruled out, preparations would have to begin before we even know whether the collision will occur. This is the result of an analysis by a US research team that has examined various conceivable measures. This not only involves a possible deflection or even destruction of the celestial body before its rendezvous with Earth and the moon at the end of 2032, but also probes that could explore it beforehand. The group comes to the conclusion that no attempt should be made to deflect the asteroid and that destruction would at least not be impossible.

Destruction with a nuclear bomb not impossible

The research work on probe and defense missions is available in advance but has not yet been independently verified. One of the team's findings is that it is not worth trying to deflect the asteroid before its possible impact on the moon. There would be a risk that the danger to Earth would increase again as a result of such a maneuver. In contrast, the researchers believe that a mission aimed at destroying the celestial body in good time, for example, with a never-tested before nuclear explosive device, is at least feasible. However, this would have to be launched long before the asteroid arrives, so preparations would have to begin quickly, despite the major uncertainties.

The team's reasoning is based on the danger that an impact of the asteroid into the moon would pose to the Earth and the nearby orbit. Months ago, other researchers had already determined that such a collision would cause impressive meteorite showers. At that time, it was said that such an impact would hurl around 100,000 tons of lunar material into space, 10 percent of which would reach the Earth within days. This could pose an immense danger to space stations, spacecraft, and satellites, which is why defensive measures should be considered, according to the team led by Brent Barbee from NASA's Goddard Space Flight Center in the new study.

2024 YR₄ caused a stir for weeks at the beginning of the year after the near-Earth asteroid was discovered on 27 December, shortly after its most recent rendezvous with Earth. Follow-up observations then initially revealed that an impact of the asteroid on Earth in 2032 could not be ruled out. For several weeks, the asteroid was at the top of ESA and NASA's lists of the most dangerous celestial bodies. At the end of February, it was then determined that there was no danger to Earth. Currently, the probability of an impact on the moon remains at 4 percent, with further observations not possible until 2026. Final certainty will probably not be available until 2028, far too late for the long preparations for a mission.

Probes could visit asteroids

The research team has now also investigated whether probes that are already completed or even in space can be repurposed for the exploration of 2024 YR₄. The asteroid probe Janus, which could not be launched, comes into question here. It could therefore be sent to 2024 YR₄ as early as 2028. Both Osiris-Apex and Psyche could therefore be redirected, but both would have to give up their current missions. At the same time, they are not designed for the rapid flyby that would then be possible, so how much they could actually find out would still have to be determined. It is not yet clear whether the work will result in concrete plans and preparations.

(mho)