Front

Sun

Back

The star at the center of our solar system.

Front

Revolution

Back

The movement of an object around another object.

Front

Rotation

Back

The spinning of an object on its axis.

Front

Rotational Axis

Back

An imaginary line through the center of an object around which it rotates.

Front

Ellipse

Back

An elongated circle, or oval shape, the shape of the planets' orbits.

Front

Solstice

Back

The two times in the year when the sun is at its greatest distance from the celestial equator.

Front

Equinox

Back

The two times in the year when day and night are of equal length.

Front

Full Moon

Back

The phase of the moon in which its whole disk is illuminated.

Front

Waxing Crescent

Back

The phase of the moon between new moon and first quarter.

Front

First Quarter

Back

The phase of the moon when it is one-quarter of the way through its orbit.