Unit 2 Review

What hold the planets in orbit around the sun?

• air

• meteors

• the force of gravity

• the galaxy

Chunks of ice and dust that travel through space are called ___________.

• planets

• asteroids

• meteors

• comets

Shooting stars are meteors as they burn in the atmoshpere.

• True

• False

The Milky Way is what type of galaxy?

• spiral

• elliptical

• irregular

• curvy

What is the icy core of a comet is called the ___________.

• meteorite

• nucleus

• galaxy

• snowball

When a meteor hits the surface, what is it called?

• a star

• a comet

• an asteroid

• a meteorite

Huge systems of billions of stars, gas, and dust held together with gravity is a ________.

• Solar System

• Galaxy

• Planets

• Gravity

Gravity is the force that causes objects with mass to attract one another.

• True

• False

What are the inner planets?

• Mercury, Venus, Earth, and Jupiter

• Venus, Saturn, Earth, and Mars

• Neptune, Mars, Mercury, and Venus

• Mercury, Venus, Earth, and Mars

Asteroids, meteors, and comets orbit the sun.

• True

• False