We may have to blow up a 60-meter asteroid to save Earth — and risk turning the Moon into a debris field
Asteroid 2024 YR4 was discovered in December 2024 and initially sparked concerns of an Earth collision. Subsequent observations ruled out a direct Earth hit, but warned of a different danger: a possible collision with the Moon. The odds of a lunar impact could reach about 4% by December 2032. If that lunar collision occurs, the Moon could be destroyed, creating a vast cloud of debris that would massively increase micrometeoroid bombardment for Earth satellites and even astronauts aboard the ISS. The scenario has been discussed by Universe Today.
In This Article:
The Moon Collision Threat: 4% Chance by 2032
The threat has shifted from Earth to the Moon. While an Earth impact is no longer considered likely, a lunar collision remains a nonzero risk, estimated at up to 4% by December 2032. A Moon destruction would unleash a debris cloud so large that it would greatly amplify micrometeoroid effects—threatening satellites and crew on the International Space Station.
Two Paths to Safety: Deflect or Destroy
To avert catastrophe, scientists have two main options: alter the asteroid’s trajectory slightly or destroy the body entirely. The ideal solution would be a small nudge to shift 2024 YR4’s orbit, but success depends on knowing the asteroid’s mass. The object’s diameter is about 60 meters, yet its mass could range from 51 million to 711 million kilograms due to density unknowns. A rapid reconnaissance mission could provide the necessary measurements, but achieving that by 2028 is uncertain. Some propose repurposing existing missions like OSIRIS-APEX or Janus and redirecting them to the asteroid.
Destruction Without Elimination: Kinetic vs Nuclear
If precise mass measurement remains impossible, a radical option emerges: destroying the asteroid. This could be done either via a kinetic impact by a powerful projectile or by a nuclear explosion above the surface. The kinetic approach would push current technology to its limits, though NASA’s DART mission has already demonstrated the capability to alter a smaller asteroid’s trajectory. A nuclear detonation of around one megaton could destroy the object regardless of its size. However, this path raises political and legal questions because humanity has not previously used such a method to defend the planet.
Time Is Running Out: Global Decisions on Planetary Defense
A decision must be made in the coming years; otherwise we risk being unprepared for a potential threat. The article highlights the need for international dialogue, planning, and investment in planetary defense research and missions. While these scenarios are hypothetical, they underscore a crucial point: proactive action today could spare future generations from a lunar-scale crisis.
