Which planet is closest to the sun?

• Earth
• Venus
• Mercury
• Mars

The motion of a body orbiting another body in space is called _____.

• revolution 
• period of revolution
• rotation
• period of rotation

Which list places the inner planets in order from largest in size to smallest in size?

• Venus, Earth, Mercury, Mars
• Mercury, Mars, Venus, Earth
• Earth, Venus, Mars, Mercury
• Venus, Mars, Earth, Mercury

Which two inner planets are known as "sister planets?"

• Venus and Mars
• Mars and Earth
• Venus and Earth

____________ is the closest planet to the sun; and has a hot heavily cratered surface.

• Mercury
• Venus
• Earth 
• Mars

The air on Venus is mostly ____.

• carbon dioxide
• oxygen
• sulfur

Which planet is do we think once had liquid water on it?

• Mercury
• Venus
• Mars
• Saturn

What are the inner planets composed of?

• gases and ice
• rock and ice
• gases and rock
• rock

Which is the second closest planet to the sun?

• Earth
• Saturn
• Venus
• Mercury

This planet is known as the red planet

• Neptune
• Mars
• Mercury
• Uranus