Very few moons

• Inner planets
• Outer planets
• Both
• Mercury

Gas giants

• Inner planets
• Outer planets
• Both
• Venus

Mercury, Venus, Earth, & Mars

• Inner planets
• Outer planets
• Both
• Pluto

Jupiter, Saturn, Uranus, & Neptune

• Inner planets
• Outer planets
• Both
• Earth

Close to the sun

• Inner planets
• Outer planets
• Both
• Kuiper Belt

Shorter revolutions

• Inner planets
• Outer planets
• Both
• Neptune

Which of the following planets experiences a runaway greenhouse effect?

• Venus
• Mars
• Mercury
• Earth

Which of the following is NOT true of all the inner planets?

• They are made of solid rock.
• They are called gas giants.
• They do not have rings.
• They have impact craters.

Mars’s volcanoes are larger than those of Earth because Mars

• is so close to the sun.
• is a much older planet.
• has a thicker lava flow.
• has no moving tectonic plates.

Impact craters are caused by

• solar bursts.
• atmospheric changes.
• exploding volcanoes.
• collisions with objects in space.