Chapter 9 Test Review

Why are the inner planets called terrestrial planets?

• because they are very hot
• b. because they resemble Earth
• because most are gas giants
• because they can support life

What is the most useful unit for measuring distances within the solar system?

• the light-year
• the parsec
• the kilometer
• the astronomical unit

Why do active planets generally have fewer impacts than bodies like the moon?

• because fewer objects orbit near these planets
• because most impacts occur in remote areas
• because geological activity removes their effects
• because many objects fall in the ocean

What is one way that gas giants differ from the terrestrial planets?

• They are much smaller.
• They are made of rocks and ice.
• Their atmosphere are massive.
• Their surfaces are hard.

What is the current theory about the origin of the moon?

• The moon was a large asteroid captured by Earth's gravity.
• The moon resulted when a large body struck Earth.
• The moon formed at the same time from the same materials.
• The moon spun off from a rapidly spinning Earth.

What is the evidence that Mars once had liquid water?

• The composition of Martian icecaps.
• Fossils of sea life recovered in missions.
• The dark color of the Martian sand.
• Features that resemble dry riverbeds.

This planet is known for its spectacular ring system.

• Earth
• Jupiter
• Neptune
• Saturn

This is the largest planet in our solar system.

• Mars
• Saturn
• Jupiter
• Pluto

This planet's year is only 88 Earth days long.

• Venus
• Earth
• Mars
• Mercury

This planet had a storm system called the Great Dark Spot.

• Neptune
• Uranus
• Saturn
• Mars