[The Moon was formed by the Earth being hit by a planetary sized object. So originally the Moon was boiling lava! At the source URL below you'll see video animations from NASA. Very cool stuff. Jan]
This image below with the red moon was what it looked like in the sky after it was formed. The smallest pic of the moon below is what it looks like in the sky now. The moon was much closer to the earth then, and thus looked massive in the sky. The moon currently appears to be the same size as the Sun, but back then the Moon was far bigger than the sun. As time has gone by the Moon has receded and become ever smaller. Its tidal effects also became smaller.
Fields of dark rock left by volcanic eruptions, mistaken for huge seas, were named "maria." Some of them make up the Man in the Moon’s face.
As large moon craters go, the giant bull’s-eye called Orientale basin is thought to be young, likely the moon’s last major body blow.
A lifetime of pummeling by space objects large and small has given the moon its familiar, pockmarked look.
The sun beats endlessly on the peaks of the south pole’s Shackleton crater, but its cold depths may not have seen light for 2 billion years.
Because Tycho crater is young, the 1-mile-tall peaks at its center are still sharp and imposing.