Unit 6 Vocabulary

Front

Asteroid

Back

A small, rocky object that orbits the sun; most are located in a band between the orbits of Mars and Jupiter.

Front

Atmosphere

Back

A mixture of gases that surrounds a planet, moon, or other celestial body.

Front

Boiling point

Back

The temperature and pressure at which a liquid becomes a gas.

Front

Comet

Back

A small body of ice, rock, and cosmic dust that follows an elliptical orbit around the sun and gives off gas and dust in the form of a tail as it passes close to the sun.

Front

Elliptical

Back

Having the shape of an oval.

Front

Kuiper belt

Back

A region of the solar system that starts just beyond the orbit of Neptune and contains dwarf planets and other small bodies made mostly of ice.

Front

Gravity

Back

A force of attraction between objects that is due to their masses and decreases as the distance between the objects increases.

Front

Greenhouse effect

Back

The warming of the surface and lower atmosphere of Earth that occurs when water vapor, carbon dioxide, and other gases absorb and reradiate energy.

Front

Habitable zone

Back

The distance from a star at which liquid water could exist on orbiting planets’ surfaces.

Front

Mass

Back

A measure of the amount of matter in an object.