Do boulders erode differently on asteroids than on the Moon? If I understand it correctly, boulders on the Moon are only found near fresh craters, because micrometeorites erode them over time. Asteroids are believed to have formed sometimes even earlier than the Moon, but some images show asteroids covered by boulders. And NASA is planning the ARM mission to go pick up a boulder from an asteroid.

Are boulders more frequent on asteroids than on the Moon, and if so, by what kind of mechanism? For example, it is not primarily micrometeorites, but temperature changes that erodes them on the Moon. Or don't microgravity objects attract as many micrometeorites as the Moon does?

Intact boulders on asteroid 25143 Itokawa:


Eroded boulders on the Moon:
The moon does attract more particles.  But more importantly, those particles hit the moon with velocities of the order of the Moon's escape velocity, 2.4 km/s.  That's a very powerful sandblaster...