This map is based largely on photographs taken by the US Lunar Orbiter 4 spacecraft. Launched on 4 May 1967, Lunar Orbiter 4 was the fourth in a series of five spacecraft designed to asist in the selection of landing sites on the Moon, in the equatorial region from 43 degrees east to 56 degrees west, for the manned Apollo misions. On 20th July, 1977, Neil Armstrong and Edwin 'Buzz' Aldrin succesfully touched down in the Sea of Tranquility in the Lunar Module of Apollo 11. The Moon is thought to have formed over 4 billion years ago from material ejected from the Earth as the result of a huge collision between Earth and another Mars-sized planetary body.
Geological map of the moon, 1967.