NAME
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Astronomy 121
Test 4
July 19, 2018
Multiple Choice Questions -- Select and circle the best answer
from the choices given.
1. Which of the following Terrestrial planets
and moons shows evidence for
plate tectonics?
a. Venus
b. Mars
c. Europa
d. Enceladus
e. Titan
2. Which of the following describes the least likely planet to have an
atmosphere?
a. large mass, small radius, low temperature
b. low mass, small radius, low temperature
c. large mass, large radius, high temperature
d. low mass, large radius, high temperature
e. large mass, large radius, low temperature
3. When Mars first formed, its climate was believed to be similar
to the current climate of the Earth. Its atmosphere then evolved
rapidly to what it is today. The current wisdom says
that the atmosphere changed because of _______ .
a. the impact of a large object which caused the
atmosphere to boil-off
b. the Solar Wind and the lack of large-scale plate tectonics
c. a stage of intense volcanism, as has also been postulated
for the Moon
d. the event that led to the formation of the Tharsis region
e. a runaway Greenhouse effect combined with plate tectonic activity
4. What evidence is there that Mars's atmosphere was thicker in the
past than today?
a. Viking found pools of liquid water in the deep craters
b. We have seen it in Earth-based studies
c. Ancient lake beds and sinuous river beds
d. Mars's atmosphere is identical to that of the Earth which has
oceans
e. Splosh craters and islands
5. The conditions in the current atmosphere of Mars are _______ .
a. such that water cannot exist in any form on the surface of
Mars
b. such that one expects a substantial stratosphere to form
c. such that liquid water cannot exist on the surface of Mars
d. such that one expects life could exist near the
equator of Mars during the summer months
6. ALH 84001 ______ .
a. is an ancient meteorite from Mars found in Antarctica in 1984
b. is unusual in that it contains magnetite crystals
c. appears to contain fossilized bacteria
d. shows carbonate grains dated to be 3.6 to 4 billion years old
e. All of the above are correct.
7. The Greenhouse Effect _____ .
a. explains why Venus's surface temperature is 800-900 F
b. explains why the average temperature of the Earth is 60-70 F and not -4 F
c. explains why Mercury's dayside surface temperature is nearly 800 F
d. only a & b are true
e. a, b, & c are all true
8. The current atmospheres of the Terrestrial planets are _______ .
a. the result of volcanic outgassing
b. the result of the capture of many comets
c. gases captured directly from the cloud that formed the Solar
System
d. A combination of a & b
e. The combination of a, b, & c
9. The Tharsis region on Mars _______ .
a. is a large impact basin that lies, for the most part,
below sea level on Mars
b. is the oldest region on Mars
c. was formed by a large impact, similar to the one that formed our Moon
d. contains both heavily cratered and relatively uncratered regions
e. was likely formed by an uplift of Mars's crust
10. The reason the atmospheres of Venus and Earth have followed such
different evolutionary paths is _____ .
a. at birth, Venus was rich in carbon dioxide while the Earth was not
b. the Earth is more massive than Venus
c. Venus is closer to the Sun than is the Earth
d. the day is longer on Venus than it is on the Earth
e. Venus does not exhibit active plate tectonics
11. The bulk of the carbon dioxide initially present in the
atmosphere of the young Earth _______ .
a. has been lost to space
b. is now contained in green plants and plankton
c. is now tied up in the crust of the Earth
d. is now contained in the oceans of the Earth
e. is now contained in the polar caps
12. The Valles Marineris _____ .
a. was likely formed by water erosion, similar to how the
Grand Canyon formed
b. was likely formed by the impact of a protoplanet
that cracked Mars's lithosphere
c. is likely the remains of a large rift zone
d. is likely the remains of ancient subduction zone formed by Mars's
only oceanic plate
e. was formed by cracking that occurred during the formation of the
Tharsis Bulge
13. The Ozone layer on the Earth ________ .
a. helps to protect the surface from Solar ultraviolet radiation
b. helps to trap water vapor in the lower atmosphere
c. supplies the heat that drives the convection that produces our weather
d. only a & b
e. a, b, & c
14. A large difference between Mars's northern hemisphere and its southern
hemisphere is _____ .
a. the southern hemisphere appears to be older than the northern hemisphere
b. the northern hemisphere is, on average, at higher elevation than the
southern hemisphere
c. the southern hemisphere contains nearly all the volcanos and also contains
the largest volcano on Mars, Olympus Mons
d. the southern hemisphere is dominated by maria-like regions while the
northern hemisphere is more highland-like in character
e. the northern hemisphere is strong evidence of on-going plate tectonic
activity on Mars
15. Outflow Channels ______ .
a. are evidence for the existence of an early tropical climate on Mars
b. are evidence for sudden catastrophic floods on Mars
c. are evidence for active volcanism in the northern hemisphere of Mars
d. are evidence for high mountain lakes on Mars
e. are evidence for ancient canals on Mars
16. The troposphere is ________ in the Earth's atmosphere.
a. where we find the ionosphere
b. where the weather is generated
c. where the Ozone layer is located
d. one of the layers where the temperature increases as you move up in
altitude
e. the outermost layer
17. Venus is very dry today with essentially no water on its surface or in its
atmosphere. What happened
to Venus's water?
a. The water exists as water vapor in the upper atmosphere of Venus.
b. The water escaped to space after Venus was struck by a Mars-sized object that
caused the oceans to boil
c. Venus was not born with any water; it was always dry.
d. The water vapor rose to high altitudes where it was broken into hydrogen
and oxygen; the hydrogen escaped to space and the oxygen formed other
molecules and compounds
e. The water slowly seeped into the crust of Venus, where it formed a
permafrost layer and/or was incorporated into rocks in the mantle
of Venus
18. The Earth's current atmosphere is composed _____ .
a. primarily of carbon dioxide and water
b. primarily of water with trace amounts of carbon dioxide
c. primarily of nitrogen but with a significant amount of oxygen
d. primarily of oxygen with trace amounts of carbon dioxide
e. primarily of oxygen with significant amounts of carbon dioxide and water
19. The portion of the northern Martian polar cap that remains in the
summer is composed of _____ while the seasonably variable
portion of the cap is
composed of _____.
a. water ice, water ice
b. carbon dioxide ice, carbon dioxide ice
c. water ice, carbon dioxide ice
d. carbon dioxide ice, water ice
e. water ice and frozen hydrogen, water ice
20. Saturn radiates 2 to 3 times as much energy as it receives from the Sun.
What is the source of the energy?
a. heat left over from its formation.
b. helium rain
c. radioactive decay
d. a and b only
e. a, b, and c
SHORT ANSWER Questions -- Answer two of the short answer questions. Each
answer is worth 10points.