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.

Which of the following planets experiences a runaway greenhouse effect?

• Venus
• Mars
• Mercury
• Earth

The factors that contribute to Mercury’s daily temperature fluctuation of about 600°C are the planet’s slow rotation and

• its close proximity to the sun.
• its dense atmosphere.
• its heavy, rocky, waterless terrain.

Which of the following is NOT true of the planet Pluto?

• It has methane icecaps.
• It orbits the sun in an ellipse.
• It is not a gas giant.
• It is a large planet.

Which of the following planets is similar to Uranus in terms of its size and mass?

• Pluto
• Jupiter
• Neptune
• Saturn

The least dense planet in the solar system is

• Jupiter
• Saturn
• Neptune
• Earth

The right combination of temperature, water, and oxygen

• affects Neptune’s orbit.
• supports life on Earth.
• causes gas giants to form.
• results in storms on Jupiter.

Which of the following planets has the most complex ring system?

• Neptune
• Saturn
• Jupiter
• Uranus