Match the definition with the correct word. Small, rocky object that orbits the Sun in the asteroid belt between Mars and Jupiter.

• star

• comet

• asteroid

• planet

Match the definition with the correct word. Average distance from Earth to the Sun—about 150 million km.

• period of revolution

• period of rotation

• comet

• astronomical unit

Match the definition with the correct word. Object made of gas, dust, and ice that moves around the Sun in an oval-shaped orbit.

• planet

• comet

• asteroid

• orbit

Match the definition with the correct word. Path an object follows as it moves around another object

• period of revolution

• orbit

• period of rotation

• star

Match the definition with the correct word. Time it takes an object to travel once around the Sun.

• orbit

• period of revolution

• period of rotation

• astronomical unit

Match the definition with the correct word. Time it takes an object to complete one rotation.

• period of rotation

• period of revolution

• orbit

• astronomical unit

Match the definition with the correct word. Object in space made of gases in which nuclear fusion reactions occur that emit energy.

• planet

• asteroid

• star

• comet

What is the closest planet to the sun?

• Earth

• Mars

• Venus

• Mercury

What is the second closest planet to the sun?

• Earth

• Venus

• Mercury

• Mars

What is the third closest planet to the sun?

• Earth

• Mars

• Venus

• Mercury