Impacts from objects in space.
Mercury is closest to the sun and has craters.
Craters.
Mercury and Mars.
Mercury
rayed craters
Yes, Mercury has craters.
Mercury has impact craters but not volcanoes.
Mercury has lots of craters and canyons
craters
Mercury has craters and mountains but no moons.
No. The craters on Mercury are from the impacts of comets and asteroids, as are most craters on objects in space. We do not have any strong evidence of volcanic activity on Mercury.
Mercury is pitted with craters because Mercury has almost no atmosphere to protect itself.
Mercury has no atmosphere and no surface fluids, so there is nothing to erode the craters.
It is mostly in the form of water ice in sheltered parts of craters.
Craters, mostly. The new Messenger photos of Mercury from just last week show craters on craters, and chains of craters. It looks a lot like the Moon, actually. You can see some photos of Mercury at the link below.
Most of the craters probably formed when the solar system was young and large impacts were far more common than they are now.
no moons but have big craters