Question: Describe the core-mantle-crust structures of the terrestrial worlds. What is

differentiation?

Answer:

Question: What do we mean by the lithosphere? How does lithosphere thickness

vary among the five terrestrial worlds?

Answer:

Question: Why do large planets retain heat longer than smaller planets?

Answer:

Question: Why does the Earth have a global magnetic field?

Why don’t the other terrestrial worlds have similarly strong magnetic fields?

Answer:

Question: Why is the Moon so much more heavily cratered than Earth?

Explain how crater counts tell us the age of a surface.

Answer:

Question: Briefly summarize the geological history of the Moon. How did the lunar maria form?

Answer:

Question: Briefly summarize the geological history of Mercury.

How are Mercury’s great cliffs thought to have formed?

Answer:

Question: Why isn’t liquid water stable on Mars today, and why do we nonetheless think it flowed on Mars in the distant past?

Answer: -No liquid water b/c cold temp. and low atmospheric pressure

-Cold temp.= frozen water

-Low atmos. press.= water would evaporate if ever thawed

-Water might exist below surface of Mars where it is warm enough to be liquid

-Evidence of liquid water: river channels and erosion of geological features

Question: What evidence tells us that Venus was repaved about 750 million years ago? What might account for the lack of plate tectonics on Venus?

Answer: -Most of Venus’ surface appears to have no craters and is approx. the same age

-Lack of plate tectonics= Stronger lithosphere than Earth= harder to break up into plates

Question: What is the longest-lasting heat source responsible for geological activity?

Answer: Radioactive decay