Chemical elements that vaporize (that is, boil) at relatively low temperatures. Examples are water (H2O), carbon dioxide (CO2), carbon monoxide (CO), methane (CH4), ammonia (NH3), potassium (K), sodiu [..]

Blocky, angular, and rough type of lava flow.

A class of stony meteorites that crystallized from magmas. The term means without chondrules.

Common particle type in lunar regolith; agglutinates consist of small rock, mineral, and glass fragments bonded together with glass—a glass that is formed by flash heating when micrometeorite impacts [..]

The geologic history of Mars has been divided into three broad time periods, or Epochs. From oldest to youngest, these are Noachian, Hesperian, and Amazonian (named after places on Mars). These Epochs [..]

A gas molecule composed of one part nitrogen and three parts hydrogen; NH3.

Dark-colored, fine-grained extrusive igneous rock with about 52 to 63 weight percent silica (SiO2). Andesite consists mainly of plagioclase and one or more mafic minerals. The word andesite is derived [..]

(Å), a unit of length equal to 10-8 centimeter.

An igneous rock made up almost entirely of plagioclase feldspar. This rock dominates the lunar highlands.

A conductor by which electromagnetic waves are transmitted or received.