Unit 4 Part 3 Vocabulary

Front

astronomical unit

Back

the distance between the Earth and the Sun used to measure distance in the solar system

Front

nebula

Back

cloud of gas and dust in space

Front

nuclear fusion

Back

a reaction where two or more nuclei combine to form a single nucleus

Front

planet

Back

a large spherical mass that revolves around a star

Front

solar system

Back

a system of objects that revolve around a star

Front

inner planet

Back

one of the four planets closest to the Sun that are solid and rocky

Front

year

Back

Front

gas giant

Back

one of the outer planets that are primarily composed of gases

Front

outer planet

Back

one of four planets found beyond the asteroid belt

Front

planetary ring

Back

a ring of material encircling a planet