Unit 1 Lesson 3 Vocabulary Terms

Front

A force of attraction between objects that is due to their masses.

Back

Gravity

Front

The path that a body follows as it travels around another body in space.

Back

Orbit

Front

In the orbit of a planet or other body in the solar system, the point that is farthest from the sun.

Back

Aphelion

Front

In the orbit of a planet or other body in the solar system, the point that is closest to the sun.

Back

Perihelion

Front

The inward force required to keep a particle or an object moving in a circular path.

Back

Centripetal Force

Front

A rotating cloud of gas and dust from which the sun and planets formed.

Back

Solar Nebula

Front

A small body from which a planet originated in the early stages of development of the solar system.

Back

Planetesimal

Front

Astronomical Unit (AU)

Back

The average distance between Earth and the sun; approximately 150 million kilometers.