They say that my surface is marked by impact craters! It sure is! These impact craters form when asteroids and comets collide into me! Ouch*
There are about half a million craters on me with diameters greater than 1 km!
Since impact craters accumulate at a nearly constant rate, the number of craters per unit area superposed on a geologic unit can be used to estimate my age. Because there isn't much of an atmosphere around me, or weather... recent geological processes ensure that many of the craters on me have remained relatively well preserved in comparison to those on Earth.
My largest crater, which is known to be the largest crater in the Solar System, is called the 'South Pole-Aitken basin'. It is on my far side between the South Pole and equator and is 2,240 km in diameter and 13 km in depth!!
