What happens if a rocket crashes into the Moon?

The Moon has no air to slow an intruder down or to carry a shockwave, so an object that reaches it hits the ground at full speed. The energy goes into excavating the regolith and ejecting material in every direction: some of that dust falls back almost immediately, and some flies off on very long ballistic trajectories, since there's no atmosphere to hold it back. There's no boom, no fire, and no noticeable effect on the satellite's orbit.

The best-documented case is a rocket body that struck near the Hertzsprung crater, on the far side, on March 4, 2022. NASA's LRO orbiter later photographed the exact spot — 5.226 degrees north, 234.486 degrees east, at an elevation of 1,863 meters — and found something unexpected: not one crater, but two. An 18-meter-diameter eastern crater overlapping a 16-meter western one.

No other known impact from a rocket body had left a double crater. The leading interpretation is that the object carried significant mass at both ends, which is unusual: a spent stage typically concentrates its mass at the engine end and is, for the rest of its length, little more than an empty tank.

Not every collision is an accident. Several missions have deliberately ended against the surface to study the material thrown up, and others have done so by mistake: the Luna 25 probe left a crater about 10 meters across on August 19, 2023, on the inner rim — with a slope of more than 20 degrees — of the Pontécoulant G crater, at 57.865 degrees south and 61.360 degrees east. Every one of these marks stays forever, because there's no erosion on the Moon to wipe them away.