NAME ________________________________________________________
Test 4
Astronomy 121
July 17, 2014
Multiple Choice Questions, 20 questions--1 point per question.
Select the best answer.
1. When Mars was young, its climate was believed to be similar
to the current climate of the Earth. Its atmosphere then evolved
to what it is today. The current wisdom says
that this was because of _______ .
a. the impact of a large object which caused the
Martian atmosphere to boil-off
b. the lack of large-scale plate tectonics on Mars
c. a stage of intense volcanism, as has also been postulated
for the Moon
d. the rapid cooling of the interior of Mars
e. the depletion of the Martian ozone layer
2. Continental plates on the Earth _______.
a. are much younger than oceanic plates
b. make up the plastic portion of the lithosphere
c. are less dense than oceanic plates
d. flow easily because they are molten iron
e. are found only near the poles of the Earth
3. 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
4. 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
5. 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
6. Of the following statements about Venus, which is NOT correct?
a. The surface of Venus is young, less than 1 billion years old
b. There is an underabundance of craters with diameter less than 30
km on Venus
c. The surface of Venus is covered primarily by rolling plains
d. The surface of Venus may show signs of recent geological activity
e. Maxwell Montes, the largest shield volcanos on Venus,
is also the largest volcano in
the Solar System
7. Strong evidence that the Moon was geologically active in the past comes
from the ____ .
a. mountains in the highland regions
b. existence of the continent-like highland regions
c. light color of the highland regions
d. maria
e. All of the above
8. The Hawaiian island chain _______ .
a. is strong evidence for the recent collision of continental plates
b. was caused by a hot-spot in the mantle of the Earth and crustal motion
c. was created by a series of impacts of large objects
d. is evidence that the Moon was once part of the Earth
e. was formed in a manner similar to the Andes in South America
9. 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
10. 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
11. The majority of Venus's surface is best described as _______ .
a. maria-like basins
b. highland regions
c. weird terrain
d. oceanic basins
e. rolling plains
12. The light-colored regions on the Moon are _______ .
a. highlands, the oldest and most heavily cratered regions on the Moon
b. ancient Lunar ocean basins
c. maria, lava-filled impact basins
d. large dust covered Lunar plains
e. mountain ranges produced during the era when plate tectonics
was active on the Moon
13. Venus is very dry today with no liquid water on its surface. What happened
to Venus's oceans (liquid 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
14. If the Ozone layer around the Earth was to disappear, then _____ .
a. the water vapor in our atmosphere would be slowly lost
b. the amount of ultraviolet radiation at the Earth's surface
would strongly increase
c. the thermosphere would also likely disappear
d. only a & b
e. a, b, & c
15. The cratering density in the Lunar highlands and maria
tells us that _____ .
a. the Moon was geologically active in the past
b. the highlands are older than the maria
c. the cratering rate on the Moon has slowed down in the last billion years
d. large impacts like the dinosaur killer on the Earth, occur every 10
million years or so on the Moon
e. plate tectonic activity on the Moon continued until
the last billion years
16. The current atmospheres of the Terrestrial planets are
most likely _______ .
a. the result of outgassing of materials trapped during the formation of the planets
b. the capture of many comets over the lifetime of the planets
c. the initial gases captured directly from the Solar Nebula 4.6 billion years ago
d. probably a combination of a & b
e. probably a combination of a, b, & c
17. The Gaia Hypothesis says _____ .
a. Venus is uninhabitable because of the Greenhouse Effect
b. the Earth is habitable because of the ionosphere and mesosphere
c. tidal forces led to the development of life on the Earth
d. the Earth is habitable because of life
e. life is possible because the Earth is habitable
18. Of the following, which best describes the
formation of Lunar maria?
a. melting and crust solidification followed by impacts
b. massive volcanism and the subsequent cooling of the crust
c. large impacts followed by lava flows
d. massive volcanism followed by large impacts
e. uplifts and subsequent collapses of the lunar crust
19. What explains the lack of small impact craters (less than 1.4 km)
on Venus?
a. objects of the size needed to produce such craters never reach the
surface of Venus due to Venus's strong magnetic field
b. the thick atmosphere burns up most objects which produce craters
of this size
c. small impact craters have been eroded by water and wind
d. the statement is incorrect -- there are many such small craters
on Venus
20. Modern data indicates that Venus _____ .
a. has extensive, rapid, and current continental drift
b. has never had volcanic activity
c. is covered mainly by continent-like regions (highlands)
d. may have had recent volcanic activity
e. is covered by a layer of water to a depth of 3.6 kilometers
Short Answer Questions--5 questions each worth 4 points.
1. What surface features and geologic events result from
Plate Tectonic activity?
What evidence
led Wegener to propose the theory of plate tectonics? Why was the
theory not immeditately accepted? What eventually led to the acceptance
of the theory of plate tectonics?
2. Describe the Faint Young Sun Paradox. What is the resolution of the
Faint Young Sun Paradox?
3. Describe the Greenhouse Effect. What are the most important Greenhouse
gases on the Earth? Is the Greenhouse Effect beneficial or harmful or
both. Explain your answer.
4. Mars does not support liquid oceans today. Is there water on Mars today? If
so, where is the water? If not, what happened to the water?
5. The most serious attempts to address (Viking and ALH8401)
the question of life on Mars were made
by the Viking Landers and the analysis of ALH8401.
Choose one and describe what was done and the results of the study
as to whether it
showed or did not show life exists or existed
on Mars. Currently, where do we stand
on the question of life on Mars.