Lunar Surface and History Practice Flashcards

A set of vocabulary flashcards covering the topographic features, composition, and formation history of Earth's moon.

Crater

The depression at the summit of a volcano or a depression produced by a meteorite impact.

Rays

Any of a system of bright, elongated streaks, sometimes associated with a crater on the moon.

Mare Imbrium

A lunar feature also known as the Sea of Rains.

Mare Tranquillitatus

A lunar feature also known as the Sea of Tranquility.

Ejecta

Material that is thrown out and then rebounds during the formation of a crater by a meteorite impact.

Highlands

Densely pitted, light-colored areas that make up most of the lunar surface.

Maria

Ancient beds of basaltic lava that originated when asteroids punctured the lunar surface, letting magma bleed out.

Rille

A long channel associated with lunar maria that looks similar to a valley or a trench.

Lunar regolith

A thin, gray layer on the surface of the moon consisting of loosely compacted, fragmented material formed by repeated meteorite impacts.

Origin of the moon model

The widely accepted theory that a body the size of Mars impacted Earth, and the resulting ejected debris eventually united to form the moon.