Asteroid 2024 YR4: potential Lunar Collision and Mitigation strategies
An asteroid discovered last year, 2024 YR4, poses a potential threat – not to Earth directly, but to the Moon. Initial calculations gave it a 3% chance of impacting Earth,but refined models now indicate a 4% probability of a collision with the Moon in 2032. This impact could create a significant debris field, endangering Earth-orbiting satellites and spacecraft.
A new study, led by brent Barbee of the University of Maryland and NASA’s Goddard Space Flight Center, explores potential methods to address this risk. The research outlines three possible approaches:
1. Deflection: this involves subtly altering the asteroid’s trajectory to avoid a collision. NASA successfully tested this technique with the DART mission in 2022, intentionally crashing a spacecraft into an asteroid to shift its orbit.However, the study deems deflection impractical for 2024 YR4 due to uncertainty surrounding the asteroid’s composition. While observed to be approximately 60 meters wide and rocky,its mass is unknown – it could be a solid rock or a loosely held collection of debris. A small push could cause it to break apart,with fragments still posing a threat.
2. Disruption: This strategy focuses on breaking the asteroid into smaller pieces, ideally less than 10 meters in size, wich would then dissipate and no longer be a hazard. Researchers believe a more powerful version of the DART spacecraft would be required for this approach, and a launch window exists to carry out the mission before 2032.
3. Nuclear Detonation: The final option involves detonating a 1-megaton nuclear explosive near the asteroid. The study suggests this could effectively destroy the heaviest possible version of 2024 YR4 with a safe detonation distance of approximately 85 meters.
If 2024 YR4 does impact the Moon, the resulting collision would eject vast amounts of rock and lunar dust.This debris could enter low Earth orbit, increasing the risk to satellites and spacecraft. Researchers estimate the debris field could create radiation levels up to 1,000 times higher than normal, perhaps endangering astronauts and operational spacecraft.
