Download Quiz # 8

Introductory Astronomy
Fall 2002
Quiz # 8
Name_________________________
1. The huge impact of an object that produced the circular Caloris Basin and its ring of
mountains on Mercury also produced
A) a very localized region of magnetic field, the only magnetic field possessed by
Mercury.
B) melting of permafrost causing massive floods that produced deep valleys on
Mercury's surface.
C) a pattern of jumbled terrain diametrically opposite to the Basin, caused by the
focused seismic waves from the original impact.
D) a very thick dusty atmosphere that still obscures the planet's surface.
2. What caused the long, meandering scarps (cliffs) that can be seen on Mercury?
A) Volcanic eruptions along crustal faults over hot-spots in the mantle.
B) Crustal movement similar to continental drift on Earth, where plates have pressed
against one another.
C) Shrinking and folding of the planet's surface as it cooled.
D) Large impacts near the end of the early period of heavy bombardment, the scarps
being eroded crater walls.
3. Both Mercury and the Earth have global magnetic fields. Compared to the Earth, which
feature does Mercury lack that is thought necessary for generating such a field?
A) Mercury does not lack any such feature.
B) A large iron core.
C) Rapid planetary rotation.
D) A molten iron core.
4. The conditions on the surface of Venus are
A) no atmosphere, and hence very variable temperatures under direct sunlight.
B) a low pressure, low temperature, CO2 atmosphere.
C) a high pressure, high temperature, CO2 atmosphere.
D) a dense atmosphere of methane, ammonia, and H2O, at a low temperature.
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5. Tectonic activity on Venus differs from that on Earth in that
A) the crust appears to be thicker, and is therefore too rigid to break up into moving
plates.
B) the surface is broken into only two plates, divided by a line at an angle to the
equator.
C) the crust appears to be thinner and weaker, and cannot support the creation and
motion of solid plates.
D) mantle convection appears to be more vigorous and has broken the lithosphere into
a multitude of small plates instead of a few large ones.
Bonus. Why has the greenhouse effect been much more efffective in raising the surface
temperature on Venus than upon the Earth?
A) Because the solar wind, the major cause of heating in the greenhouse effect, is far
more intense at Venus's distance from the Sun and Venus has no magnetic field to
deflect this solar wind. atmosphere.
B) Because CO2, which traps heat from the planet's surface, is the major component
in the very dense Venusian atmosphere while it is a only a minor constituent of the
Earth's.
C) Because the oceans upon Earth have acted as a thermostat in absorbing much of
the heat that would otherwise have raised the Earth's temperature significantly.
D) Because the surface of Venus is much more effective than that of Earth in
absorbing solar visible and UV radiation.
I pledge that I have neither given nor received any unauthorized aid on this assignment.
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Answer Key
1.
2.
3.
4.
5.
6.
C
C
D
C
A
B
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