PES 105 – General Astronomy – Exam #2
The Earth; The Moon; Time Keeping Systems
CHAPTER 5 — The Earth
1.
What causes the Earth’s spherical shape?
A. Rapid rotation
B. The Earth’s gravity
C. The shape of the Earth’s core
D. The Sun’s gravity
2.
What causes the Earth’s equatorial bulge?
A. The Earth’s rotation
B. The gravitational attraction from the Sun
C. The gravitational attraction from the Moon
D. The combined gravitational attraction from the Sun, the Moon and the other planets
3.
Which of the following provides significant information about the Earth’s core?
A. Radioactivity from the core
B. Analysis of the Earth’s density
C. Study of the seismic waves
D. All of the above
E. Only B and C above
4.
Which of the following is the most abundant gas in the Earth’s atmosphere?
A. Oxygen
B. Nitrogen
C. Carbon dioxide
D. Water vapor
E. Hydrogen.
5.
Which of the following result from the Coriolis effect?
A. The tradewinds
B. The Gulf stream
C. The jet streams in the atmosphere
D. The majority of the large scale weather patterns and ocean currents
E. All of the above.
6.
Which of the following are possible explanations for the high temperature of the Earth’s core?
A. The Sun’s radiation
B. The greenhouse effect
C. Decay of radioactive materials at the Earth’s interior produces heat
D. As material accumulated to form the Earth, gravitational potential energy was released
E. Both C and D could account for the heat at the Earth’s core
7.
Which of the following is true about the Earth’s magnetic field?
A. It protects the Earth from energetic particles emitted by the Sun
B. The polarity of the Earth’s magnetic field changes and probably reverses every 10,000 years
C. It is due to the combined effect of the Earth’s rotation and convection currents in the molten core
D. The magnetic field interacts with charged solar particles to create the aurora
E. All of the above.
8.
The average density of the Earth is about 5.5 g/cm3 yet most of the rocks on the Earth’s surface are
about 3 g/cm3. What could we conclude from this comparison?
A. Most of the Earth’s rocks come from outer space
B. The water in the oceans makes the average density of the Earth low
C. The Earth’s interior must have material with density higher than 5.5 g/cm3
D. The rocks on the Earth’s surface must be very rich in silicates
E. None of the above.
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PES 105 – General Astronomy – Exam #2
The Earth; The Moon; Time Keeping Systems
9.
The Earth’s equatorial diameter is slightly larger than the diameter through the poles. The difference
in diameters causes ________.
A. Gravity to be stronger in the poles
B. Gravity to be weaker in the poles
C. No effects on gravity.
10. The Earth is about _____ years old.
A. 4.5 million
B. 4.5 billion
C. 1 million
D. 1 billion
11. The shift of the Earth’s plates due to tectonic motion is typically in the order of ______.
A. A few hundred meters per year
B. A few centimeters per year
C. A few centimeters per century
12. Match the Earth’s properties listed in the left column with their probable cause as listed in the right
column. Each entry in the right column can be used once, more than once or not at all.
___1.
___2.
___3.
___4.
___5.
___6.
___7.
Plate tectonics
Aurora
Van Allen radiation belts
Precession
High pressure in the core
Spherical shape
Greenhouse effect
A.
B.
C.
D.
E.
Equatorial bulge
The Earth’s gravity
The Earth’s magnetic field
Convection in the Earth’s interior
Carbon dioxide and water
13. Match the items listed in the left column with the entries listed in the right column. Each entry in the
right column can be used once, more than once or not at all.
___1.
___2.
___3.
___4.
___5.
___6.
___7.
Used to determine age of the Earth
Caused by Earth’s rotation
Causes plate tectonics
Causes precession of Earth’s axis
Causes the trade winds
May be source of heat in Earth’s interior
Used to probe Earth’s interior
A.
B.
C.
D.
E.
Equatorial bulge
Convection in Earth’s interior
Coriolis effect
Radioactive decay
S and P seismic waves
CHAPTER 6 — The Moon
14. What is the origin of regolith?
A. Material deposited by volcanic eruptions
B. Material eroded by dust storms
C. Material fragmented by seismic waves
D. Rock crushed by meteoritic impacts
E. The origin is unknown
15. Why do astronomers believe that the lunar maria are younger than the highlands?
A. The maria are more cratered
B. The maria are lighter in color
C. The maria have fewer craters
D. The highlands have evidence of ancient river beds.
16. Astronomers attribute to the lack of atmosphere on the Moon to:
A. The lack of surface water
B. The lack of meteoric/comet impacts on the Moon
C. The absence of volcanic activity
D. The gravitational force of the Moon is too weak to keep gases from escaping
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PES 105 – General Astronomy – Exam #2
The Earth; The Moon; Time Keeping Systems
17. An astronaut on the far side of the Moon would able to see:
A. The same side of the Earth all the time
B. All parts of the Earth, at some time or another
C. The Earth rising and setting every 29 days
D. Would not be able to see Earth
18. Rays appear to radiate from some of the Lunar craters. What is the origin of these rays?
A. Radiation emitted from the hot crater
B. Cracks on the Moon’s crust
C. Volcanic lava flows from the crater
D. Streaks of pulverized rock
E. Upwelling material fro m the Moon’s interior.
19. Which of the following scenarios should we expect as the result of tidal braking?
A. The Moon will slow down and move much closer to the Earth
B. The Earth will slow down and reverse its spin
C. The Moon will be visible from one side of the Earth only.
D. The Moon will escape from the Earth’s gravitational field.
20. Astronomers knew before the lunar exploration missions that the Moon lacked atmosphere. Which of
the following was their strongest evidence supporting the hypothesis that the Moon lacks atmosphere.
A. The lack of auroral phenomena on the Moon
B. The fact that when the Moon eclipses a star, the starlight vanishes abruptly without additional
scintillation
C. The fact that the Moon is too hot to have atmosphere
D. The fact that volcanic eruptions were not observed on the Moon
E. All of the above.
21. The Lunar surface shows meandering features known as rilles. What is the origin of these rilles?
A. Ancient riverbeds
B. Lines carved by meteoric impacts
C. Evidence of active plate tectonics on the Moon
D. Canyons carved by lava flows
22. Which of the following is at present the most widely accepted theory about the origin of the Moon?
A. The Moon was captured by the Earth’s gravity
B. The Moon formed simultaneously with the Earth
C. The Moon formed from a chunk of mass that was ejected in space by the Earth’s rapid rotation
D. The Moon formed from material blasted out of the Earth during a collision with a Mars-sized
planetesimal.
23. The lunar craters originated from _______.
A. Objects striking the surface
B. Volcanic explosions
24. The crust of the Moon is ______ on the side facing the Earth.
A. Thinner
B. Thicker
25. Synchronous motion of the Moon refers to the fact that the Moon completes one rotation around the
axis and one revolution around the Earth at the same time period.
A. True
B. False
26. As a result of tidal braking, the Moon to Earth distance is increasing.
A. True
B. False
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PES 105 – General Astronomy – Exam #2
The Earth; The Moon; Time Keeping Systems
27. Match the lunar surface features in the left column, with their probable cause from the list in the right
column. Each entry in the right column can be used once, more than once or not at all.
___1.
___2.
___3.
___4.
___5.
Straight rilles
Meandering rilles
Rays
Most craters
Regolith
A.
B.
C.
D.
Lava flows
Volcanic activity
Surface cracks
Meteoric impacts
28. Match the phenomena listed in the left column with the Moon phase during which the phenomena
occur, as listed in the right column. Each entry in the right column is used once and only once.
___1.
___2.
___3.
___4.
___5.
Spring tides
Neap tides
Low tide
Lunar eclipse
Solar eclipse
A.
B.
C.
D.
E.
Full Moon
New Moon
Full or New Moon
1st of 3rd Quarter phase
Any phase of the Moon
ESSAY 2 — Keeping Time
29. Which of the following statements is not correct?
A. A sidereal day is the time between successive risings of a star.
B. The time between successive sunrises is exactly 24 hours
C. The mean solar day is exactly 24 hours
D. The sidereal day is 23 hours and 56 minutes and 4 seconds
30. The sidereal day is ____ the mean solar day.
A. Shorter than
B. Longer than
C. The same as
31. Match the entries listed in the left column with the entries in the right column.
___1.
___2.
___3.
___4.
___5.
24 hours
23 hours 56 minutes 4 seconds
12 daylight hours every day
12 daylight hours everywhere on Earth
If you use this clock, stars always rise at the same
time in your location
A.
B.
C.
D.
E.
Length of sidereal day
Clock keeping sidereal time
During equinoxes
Mean solar day
On the equator
32. Match the entries listed in the left column with the entries in the right column.
___1. Julian Date System
___2. Gregorian Calendar
___3. Roman (Julian) Calendar
___4. Muslim and Jewish Calendars
A. Created by Julian Ceaser and contains the months
that are familiar today, but drifted away from
astronomical observations
B. Spans most historically observed astronomical
phenomena since 4712 B.C.
C. Correctly adds/removes leap years in order to
match astronomical observations
D. Based on lunar months; drift away from
astronomical observations (unless corrected by
adding occaisional days and months)
33. The International Date Line and the Prime Meridian are on the _______ side of the Earth
A. Same
B. Opposite
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