It is a vital part of astronomy and is often the very first step to understanding an existing planet or studying a new one. There is still much to be discovered, not only in our neighboring terrestrial planets, but our own as well.

Geology has an important role in the solar system and beyond: the first images of the Martian mountains were looked at by astronomers, but analyzed by geologists. The cratered face of the moon was sampled, in person, by planetary geologist Harrison Schmitt. The volcanic plumes on Io, and the icy ridges of Europa, are studied by geologists. When the first man-made satellite reaches Pluto in 2015, geologists will chart its never-before seen surface.

It is in the rocks, where life is born.