And they're not purely hypothetical: An asteroid known as 2024 YR4 is estimated to have a 4% chance of hitting the moon in 2032. Various key characteristics about asteroid 2024 YR4 aren’t known, including its mass, which would be critical in figuring out how to properly “disrupt” it without creating more problems. Asteroid 2024 YR4 was first detected by the Asteroid Terrestrial-impact Last Alert System station in Chile in December. With Earth now thought to be in the clear, asteroid 2024 YR4 has an estimated 4.3% chance of smacking into the moon. But a successful deflection would also require knowing the mass of asteroid 2024 YR4, Brisset said.