Abstract
An important piece of knowledge about any ex- traterrestrial body, such as the moon or Mars, is its elemental make-up. The elemental composition at a given site is related to the type of rock which is present at the site. The type of rock ex- pected to be present is dependent on the geological and geochemical processes which have occurred dur- ing the history of the body. Gross questions about a planet’s history which could be partly answered by elemental analysis deal with the relative im- portance of volcanic and meteor impact activity, the degree to which differentiation has taken place, and the role of water throughout the history.