Download Astronomy 311: Terrestrial Planet Geology • What is the most

Astronomy 311: Terrestrial Planet Geology
• What is the most important long-lasting internal heat source responsible
for geological activity? a) accretion b) radio-active decay c) sunlight?
• In general, what kind of planet would you expect to have the thickest lithosphere? a) the largest planet b) the smallest planet c) the planet furthest
from the Sun
• Which of a planet’s fundamental properties has the greatest effect on its
level of volcanic and tectonic activity? a) size b) distance from Sun c)
rotation rate?
• Suppose we make the following discoveries. Using your knowledge of planetary geology, decide whether the following discoveries should be considered
reasonable or surprising, explaining your answer in terms of a terrestrial
planet’s fundamental properties.
– The next mission to Mercury photographs part of the surface never
before seen and detects vast sand dunes.
– Seismographs placed on the surface of Mercury record frequent and
violent eqrthquakes.
– A future orbiter observes a volcanic eruption on Venus.
– A Venus radar mapper discovers extensive regions of layered sedimentary rocks, similar to those found on Earth.
– Radiometric dating of lunar rocks from a crater show the crater was
formed only a few tens of millions of years ago.
– Water is found on Martian crater bottoms.
– Liquid water is found underneath the Martian surface.
– Clear cutting the Amazon rain forest reveals vast regions of ancient
terrain that is as heavilyt creteres as the Moon.
– Seismic studies on Earth reveal a lost continent that held great human
cities a few thousand years ago but that is now buried deep underground of the western coast of Europe.
– We find a planet in another Solar System that orbits at the same
distance a Sun-like star and has Earth-like plate tectonics but is only
the size of the Moon.
– We find another planet in another Solar System that is as large as
Earth but is as heavily cratered as the Moon.
– We find a planet in another Solar System with Earth-like seafloor crust
and continental crust but that apparently lacks plate tectonics or any
other kind of crustal motion.
1