Front

The action of rotating around an axis or center.

Back

Rotation

Front

An instance of revolving.

Back

Revolution

Front

A planet that's mainly made of rock and metal, and has a solid surface.

Back

Terrestrial Planets

Front

They orbit far from the sun. These planets have no solid surfaces and are essentially large balls of gas composed primarily of hydrogen and helium.

Back

Jovian Planets

Front

Planets whose orbit lies within the asteroid belt, i.e. Mercury, Venus, Earth, or Mars.

Back

Inner Planets

Front

Planets in the Solar System that are beyond the asteroid belt.

Back

Outer Planets

Front

The complete range of all types of radiation that has both electric and magnetic fields and travels in waves.

Back

Electromagnetic Spectrum

Front

The speed at which light travels in a vacuum, and it's a fundamental physical constant.

Back

Speed of light

Front

A unit of measurement equal to 149.6 million kilometers, the mean distance from the center of the earth to the center of the sun.

Back

Astronomical Unit

Front

A unit of astronomical distance equivalent to the distance that light travels in one year.

Back

Light year