The Moon was initially the most heavily studied, as it always exhibited details on its surface, due to its proximity to the Earth, and the technological improvements gradually produced more detailed lunar geological knowledge.
Mjesec je u početku bio najbolje istraženo nebesko tijelo jer je uvijek pokazivao detalje na svojoj površini zbog svoje blizine Zemlji, a tehnološka poboljšanja postupno su stvarala detaljnije lunarno geološko znanje.