Astronomy 4

Reading Overview for Exam 3

Key Terms

Chapter 8: Earth as a Planet




greenhouse effect

greenhouse gas

mass extinction


plate tectonics

rift zone

seismic wave


Chapter 9: Cratered Worlds (the Moon and Mercury)


mare (plural: maria)

relative age


impact crater

central peak


Four hypotheses of Moon's origin:




giant impact

Chapter 10: Earthlike Planets (Venus and Mars)

Venus's atmosphere composition

runaway greenhouse effect

coronae (on Venus)

Mars's atmosphere composition

Mars's volcanoes and canyons

Water on Mars

NOTE: There will be no short-answer question on exam 3. The following questions may provide the basis for some multiple-choice questions, however.

Review Questions

Chapter 8
How do we know what the Earth's core and mantle are made of?
What is the source of Earth's magnetic field?
Why are we concerned about increases in greenhouse gases in Earth's atmosphere?

Chapter 9
How could you find the relative ages of the Moon's maria and highlands?
Why does the Moon not have an atmosphere?
How does the giant impact hypothesis explain the Moon's lack of iron?  Of volatiles?
What evidence can you cite that Mercury has a partially molten, metallic core?

Chapter 10
List several ways that Venus, Earth, and Mars are similar.
List several ways that Venus, Earth, and Mars are different.
What evidence shows that Venus has been resurfaced within the last billion years?
What is the runaway greenhouse effect?
What evidence do we have that there was liquid water on Mars in the past?