Selenography is the study of the formation of the moon.
Using principles of supposition, it establishes the order that events took place and the impact (directly and indirectly) on features on the lunar surface.
The moon has been 'dead' for about the last billion years following the impacts that led to the rayed crater systems such as Copernicus, Tycho and Kepler. Minor changes still occur due to collision from meteors and smaller asteroids.
The following table outlines the major selenology eras over the past 4500 million years - the formation of the solar system.