Astronomy and Earth Science Terms

Front

Axis

Back

An imaginary line about which a body rotates. Moves through the north and south poles.

Front

Crescent moon

Back

The phase of the moon when a small part of it is visible,

Front

Eclipse

Back

An event where one celestial body moves into the shadow of another celestial body.

Front

Equinox

Back

When day and night are of equal length. On or around March 21 and September 21 each year.

Front

Full moon

Back

The phase of the moon when it is fully illuminated as seen from Earth.

Front

Gibbous moon

Back

The phase of the moon when more than half of it is illuminated.

Front

Gravity

Back

The force that attracts a body toward the center of the earth, or toward any other physical body having mass.

Front

High tide

Back

The state of the tide when at its highest level.

Front

Insolation

Back

The amount of solar radiation reaching a given area.

Front

Low tide

Back

The state of the tide when at its lowest level.