Test 2
LAST NAME ______________________________
FIRST NAME _____________________________
Test 2
Astronomy 121
30 Multiple Choice Questions. Select the best answer.
(2 points per question)
1. A comparison of the atmospheric pressures of Venus and the Earth yields _______.
a. the relative densities of the cores of the planets
b. the relative ages of the planet
c. the relative masses of the planets
d. the temperatures of the gas molecules in the atmospheres of the planets
e. the relative masses of the atmospheres
2. Magnetic fields are produced by __________ .
a. the decay of radioactive nuclei
b. electrical currents
c. chemical differentiation
d. the convective motions in the asthenosphere
e. volcanic activity
3. The asthenosphere is _________.
a. the plastic layer beneath the solid surface of the Earth
b. the lowest layer of a planet's atmosphere
c. the region at the very center of a planet
d. the least dense region of the lithosphere
e. the molten layer beneath the solid surface of the Earth
4. The seismic waves that can travel through liquids and solids are ________ .
a. P waves
b. S waves
c. microwaves
d. a & b only
e. a, b, & c
5. 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
6. The troposphere is ________ in the Earth's atmosphere.
a. where heat is transported by convection
b. where the weather is generated
c. the lowest layer
d. where the water vapor is trapped
e. All of the above are correct fill-ins for the question.
7. The majority of Venus's surface is best described as _______ .
a. rolling plains
b. continental, highland regions
c. lowlands
d. oceanic basins
e. uplifts similar to the Tharsis Bulge
8. The Greenhouse Effect on the young Venus was _______ .
a. intensified by the presence of technologically advanced life forms
b. weakened by the presence of a thick Ozone layer
c. intensified by water vapor
d. intensified by an anomalous overabundance of CO2 compared to the Earth
e. very mild because of its thick cloud layer
9. The fluidized ejecta surrounding splosh craters are strong
evidence for ______ .
a. a permafrost layer on Mars
b. the existence of an early tropical climate on Mars
c. current volcanism on Mars
d. plate tectonics on Mars
e. a molten iron core on Mars
10. On the Earth, the large impacts (those that produce
craters of diameter around 100 km) _______ .
a. are believed by many to have caused the extinction of the dinosaurs
b. occur every 100 million years or so
c. are thought to have produced the volcanoes in the Cascade mountain range
d. a & b only
e. a, b, & c
11. The light-colored regions on the Moon are _______ .
a. the highlands, the least heavily cratered regions on the Moon
b. the maria, the least heavily cratered regions on the Moon
c. the maria, mountainous regions produced during the period of
heavy bombardment
d. the remnants of the oceanic basins (oceanic plates)
e. the highlands, the oldest surface regions on the Moon
12. On the Earth, the oceanic plates _______.
a. are the oldest portions of the lithosphere
b. are the plastic portions of the lithosphere
c. are denser than the Continental plates
d. are thought to be molten iron
e. are ancient, some were formed as long as 4.1 billion years ago
13. The Tharsis region on Mars _______ .
a. contains the largest volcano in the Solar System
b. lies for the most part below the sea level on Mars
c. is an ancient region similar to the highlands on the Moon
d. contains both heavily cratered and relatively uncratered regions
e. is strong evidence that, in the past, Mars showed extensive plate
tectonic activity
14. Which of the following statements about the surface of Venus is correct?
a. The surface of Venus is thought to be young, less than 1 billion years old
b. There is an overabundance of craters with diameters less than 30
km on Venus
c. Most of the surface of Venus is old, more than 3.6 billion
years old
d. The surface of Venus is covered primarily by continental-type
regions
e. Venus's lithosphere is anomalous in that it is composed primarily of iron
15. The majority of the surface features on Mercury were formed through _______ .
a. plate tectonic activity
b. wind and water erosion
c. volcanism
d. impacts
e. uplifts
16. Near subduction zones, we expect _______ .
a. to find large changes in the level of the oceans
b. to find active volcanism
c. to see the formation of island chains (like Hawaii)
d. to observe the creation of new continental crustal material
e. to see sea-floor spreading
17. Because crustal material is continuously created, _______.
a. the Earth is growing in diameter by around 2 - 3 cm per year
b. the landmasses (continents) are continuously destroyed
c. the Earth is getting more massive as time goes by
d. the ocean basins are replaced every few hundred million years
e. the sea level is rising by around 2 - 4 cm per year
18. The mountains on the Moon are _______ .
a. strong evidence for the recent collision of continental plates
b. caused by hot-spots in the mantle of the Moon
c. created by the impacts of large objects on the Moon
d. evidence of extensive volcanism in the early history of the Moon
e. evidence that the Moon was once part of the Earth
19. We know that the maria formed after the Lunar highlands because _______ .
a. the highlands are more heavily cratered than are the maria
b. the maria are at lower elevations than are the highlands
c. there is a lack of maria on the far side of the Moon
d. the highlands are darker in color than are the maria
e. most of the Moon is covered by highland regions
20. Terrestrial and Jovian planets have different chemical compositions
because ________ .
a. they formed in parts of the Solar Nebula which had radically
different chemical compositions
b. of the high temperatures in the inner solar nebula
c. Terrestrial planets are smaller than the Jovian planets
d. Jovian planets have stronger magnetic fields
e. Jovian have many moons which altered their atmospheres
21. The portion of the northern Martian polar cap which 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
22. The Martian plains are plentiful in the _____ hemisphere;
craters are plentiful in the _____ hemisphere,
a. northern, northern
b. southern, southern
c. southern, northern
d. northern, southern
23. The bulk of the carbon dioxide initially present in the
atmosphere of the young Earth _______ .
a. has been lost to space
b. is contained in green plants and plankton
c. is tied up in the crust of the Earth
d. is contained in the oceans of the Earth
e. is contained in the polar caps
24. 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 that life could exist near the
equator on Mars during the summer months
25. 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
atmosphere to boil-off
b. the lack of large-scale plate tectonics
c. a stage of intense volcanism, as has also been postulated
for the Moon
d. the rapid cooling of the interior of the planet
e. the depletion of the Martian ozone layer
26. Which of the following suggests that Mars's atmosphere was thicker in the
past?
a. outflow channels
b. splosh craters
c. the permafrost layer
d. the sinuous dried riverbeds
e. the northern residual polar cap
27. What important event occurred while the Sun was in its T Tauri
phase, the phase when the young Sun developed an intense Solar Wind?
a. Jupiter was formed
b. the Earth-Moon system was formed
c. the Sun ran out of fuel and started to fade
d. the planet formation process stopped
e. the period of heavy bombardment
28. The asteroids are thought to be _______ .
a. a Terrestrial planet which was broken-up during a close encounter with
the Sun
b. small objects formed outside of the Solar System which were
subsequently captured
c. comets which were trapped in the inner Solar System by the
Earth
d. planet-building material which Jupiter did not allow to form
into a planet
e. the largest moon of Mars which was destroyed during a close
encounter with Jupiter
29. A key to why there is a large difference between
the Jovian planets and the Terrestrial planets is _______ .
a. that water was able to exist in solid form (ice) starting just inside the
orbit of Jupiter
b. the fact that the outer Solar System contains more hydrogen
than the inner Solar System
c. the ability of rocky material to be in solid form only around
the orbits of the Jovian planets
d. that there was no gas in the inner Solar System
e. we do not understand why the Jovian planets are so different
from the Terrestrial planets
30. The lunar maria _______ .
a. are the result of the flooding of large impact basins
b. have much higher crater densities than the surrounding
regions
c. are spread uniformly over the surface of the Moon
d. are unique to the Moon; they have no counterparts on
other planets
e. All of the above are correct statements about the lunar
maria
10 Short Answer Questions (4 points per question)
1. Radioactive age dating is used to determine the age of rocks. Suppose I
have a Moon rock, how do we determine its age using radioactive age
dating?
2. What is Chemical Differentiation? What supplied the heat
which led to the chemical differentiation of the Earth?
3. List the ways astronomers probe the interiors of Terrestrial planets. What
has been the best method for the Earth? What has been the best
method for Venus?
4. Do we believe that Plate Tectonic activity occurred on Mars? Cite a piece of evidence that supports
your answer. Why is the fact you quote evidence for or
against plate tectonic activity?
5. Venus is very dry compared to the Earth. How dry is Venus compared to the
Earth? What happened to Venus's water?
6. What is the Gaia Hypothesis? According to the Gaia Hypothesis,
as described in class,
how would the Earth react
if the energy output of the Sun were to increase?
7. In what level of the atmosphere do we find the Ozone layer?
Give two important functions mentioned in class that the
Ozone layer performs for us.
8. What is the Greenhouse Effect?
How would the current climate of the Earth be different if the Greenhouse
Effect had never occurred?
9. More than 70 extra-Solar planets have been discovered in the last 5
years. Describe the method used to discover these planets.
10. How do we know that ALH84001 came from Mars? What evidence that past life
existed on Mars was found in ALH84001? Is the evidence compelling?
| |
Points |
Multiple Choice
|
|
Short Answer
|
|
TOTAL
|
|