Space Station Glossary L

L

Light Curve:

A plot showing how the light production of a star (or other variable astronomical object), changes with time.

Light-Year:

The distance that a particle of light (photon) would travel in a year — about 10 trillion kilometers (6 trillion miles). It is a useful unit for measure distances between stars.

Lithosphere:

The solid part of a planet’s surface, calm of the crust and upper mantle. On Earth, it includes the continent and the sea floor.

Local Group:

A small cluster of additional than 30 galaxies, including the Andromeda galaxy, the Magellanic Clouds, and Milky Way galaxy.