ASTR101 PRACTICE EXAM I
MULTIPLE CHOICE QUESTIONS (50 pts.)
Choose the BEST answer to each of the following questions using what you have learned in ASTR 101. (2 pts. each)
1. Which of the following best describes our Earth as depicted in the “Powers of Ten” video and the book’s first chapter?
A. the largest planet in the Milky Way galaxy
B. a planet orbiting a star that lies within a spiral galaxy
C. a star within a spiral galaxy
D. a star at the center of a spiral galaxy orbiting a solar system
E. the center of a solar system sitting in a cluster of galaxies at the universe’s edge
2. An observer at the equator sees
A. no circumpolar stars.
B. only circumpolar stars.
C. a mix of 50% circumpolar stars and 50% non-circumpolar stars.
D. more circumpolar stars during the summer.
E. more circumpolar stars during the winter.
3. In order for an annular eclipse to occur
A. the moon’s phase must be full.
B. the Earth must be near either equinox.
C. the Earth must be near either solstice.
D. the new moon must be near its greatest distance from Earth.
E. the new moon must be near its closest distance from Earth.
4. You know that F = G m1 x m2 / d2
On the Earth, Mrs. Deming's cat, Smokey, weighs 10 lbs. What would Smokey weigh on a planet 5 times as massive as Earth and whose radius is 5 times larger than Earth's radius?
A. 2 lbs.
B. 5 lbs.
C. 10 lbs.
D. 50 lbs.
E. 250 lbs.
5. The North Star has changed from Thuban (3000 B.C.) to Polaris (2004 A. D.). Why?
A. retrograde motion
B. synchronous rotation
C. refraction
D. precession
E. differentiation
6. On Earth the crustal plates move because
A. they float on the oceans.
B. hot lava bubbles up and cracks the crust.
C. the warm mantle has currents that drive the motion.
D. gravity pulls weaker layers of crust downward.
E. the Sun and Moon gravitationally pull in opposite directions.
7. Galileo noticed that Venus looked largest in angular size through his telescope when he observed the ______phase.
A. new
B. crescent
C. quarter
D. gibbous
E. full
8. An asteroid orbits the Sun. The semimajor axis of the orbit is 4 astronomical units. Using Kepler’s third law (P2 = a3), find the orbital period of the asteroid.
A. 2 years
B. 4 years
C. 8 years
D. 16 years
E. 64 years
9. The greatest contribution to astronomy made by Tycho (Brahe) was
A. his production of an accurate model of the Solar System.
B. the invention of the telescope.
C. his description of gravity.
D. a collection of precise observations of planetary positions.
E. confirmation of stellar parallax.
10. Which surface feature dominates on Mercury?
A. volcanoes
B. canyons
C. channels
D. polar caps
E. impact craters
11. On the Autumnal Equinox (Sept. 22 at 12:30 PM EDT) from College Park, the Sun was above the horizon for more than 12 hours. Why?
A. The equinox occurred at mid-day so the Sun’s timing was disrupted.
B. For our latitude the Sun is always up more than 12 hours.
C. The year 2004 was a leap year, so the true equinox was a day earlier.
D. Atmospheric refraction lengthens the time that the Sun is visible each day.
E. The Sun was visible for exactly 12 hours for a southern hemisphere observer,
since the Sun was moving into the southern half of the sky.
12. The Earth and the Moon are roughly at the same distance from the Sun, yet the Moon has a much more extreme temperature range (-280oF to +280oF). Why?
A. The Moon has a lower average density.
B. The Moon has no magnetic field.
C. The Moon has no atmosphere.
D. The Moon is much more reflective than the Earth.
E. The Moon orbits the Earth.
13. The latitude of College Park is 39oN. From this information you know that the ______is 39o above the northern horizon.
A. Sun
B. ecliptic
C. zenith
D. North Celestial Pole
E. Celestial Equator
14. Monuments like Stonehenge in England, the tomb at Newgrange Ireland, and the Medicine Wheels in North America demonstrate that ancient civilizations had a knowledge of
A. predicting planetary alignments.
B. the position of the Sun on important seasonal dates.
C. the elliptical nature of planetary orbits.
D. the epicycular nature of planetary orbits.
E. the 1054 supernova event.
15. Today Astrology
A. is a well respected branch of Astronomy.
B. can be used to predict the occurrence of events with complete accuracy.
C. has numerous statistical and scientific studies to support its claims of accuracy.
D. has mathematical formulae which relate the astrological force to factors such
as distance and mass.
E. lacks support for its claims when scrutinized using the scientific method.
16. According to Kepler’s laws, planets
A. shine by reflected sunlight.
B. move on epicycles.
C. rotate faster with increasing distance from the Sun.
D. do not show phases.
E. move fastest when closest to the Sun.
17. Suppose that you are standing on the Moon and you saw the Earth high overhead. As time went by, the Earth would
A. slowly set in the west.
B. slowly set in the east.
C. remain high in the sky.
D. go down to the western horizon, and then rise again.
E. move from NCP to SCP.
18. A transit occurs when
A. Mars is opposite the Sun.
B. Jupiter moves behind the Sun.
C. Mercury or Venus pass in front of the Sun.
D. the Moon passes through the umbra.
E. the Moon passes through the penumbra.
19. During a phone conversation with my friend in London, England, he mentions that the full moon looks beautiful tonight. It is midnight in London and 7 PM in College Park. It is clear so I look out my east window and see
A. the full moon.
B. a quarter moon.
C. a gibbous moon.
D. a crescent moon.
E. no moon at all.
20. What is meant by differentiation of a planet?
A. This term comes from calculus and was used by Newton to derive Kepler’s
laws.
B. This term is used to describe the list of differences between the planets.
C. During formation, densest materials sank toward the core of a planet.
D. Each planet is unique.
E. This process leads directly to the formation of moons.
21. Observations of Mars show that
A. there are seasonal changes.
B. there are impact craters.
C. there are volcanoes.
D. all of the above.
E. only answers A and C
22. A huge number of impact craters are observed on the Moon, but relatively few exist on Earth. Why?
A. All meteors burn up in the Earth’s atmosphere.
B. The Moon’s gravity is too weak to deflect any meteors.
C. The Earth has erosion and geological activity.
D. The Earth is differentiated but the Moon isn’t.
E. The Earth has a magnetic field, which deflects the impacting bodies.
23. The statement that “astronauts are weightless on the Moon” is
A. true, because they are in a vacuum.
B. true, because there is no gravitational force on them when they are on the
Moon.
C. true, because they have to wear protective spacesuits.
D. false, because they wear special magnetic shoes to hold them on the Moon.
E. false, because the Moon exerts a gravitational force on their bodies.
24. Suppose that you are an astronaut taking a space walk to fix your spacecraft with a hammer. Your lifeline breaks and is just out of your reach. The jets in your backpack are out of fuel. What could you do to save yourself?
A. Throw the hammer at the spacecraft.
B. Throw the hammer away from the spacecraft.
C. Kick your feet in a cyclic pattern.
D. Fling your arms in circles.
E. Kiss your ship goodbye.
25. The lack of plate motions on Mars has
A. caused the planet’s core to shrink.
B. allowed the planet’s atmosphere to escape.
C. prevented the production of a magnetic field.
D. contributed to the production of huge shield volcanoes.
E. destroyed most of the planet’s impact craters.
Short Answer Questions (50 pts.)
Please answer each of the following questions as completely as you can using what you have learned in ASTR 101. After you have finished a part, please go back and re-read the question, to make sure you have answered what was asked.
26 a) Make a clearly labeled sketch showing the positions of the Sun and the Earth on the summer solstice (June 21). (4 pts.)
b) What season does each hemisphere experience at this time? Explain why. (6 pts.)
EXTRA CREDIT (2 pts.)
Why do the seasons lag? (warmest/coolest weather doesn’t occur on exact solstice date)
27. a) Describe 2 methods for determining the Earth’s interior structure. What has been revealed about the Earth’s interior structure? (6 pts.)
b) Describe the leading hypothesis that explains the Moon’s origin. (3 pts.)
EXTRA CREDIT (2 pts. maximum)
What is an epicycle and how was it used?
28. a) Describe in detail two observations that support the hypothesis that flowing water existed in the past on Mars. (4 pts.)
b) Explain how ozone in Earth’s stratosphere protects life at the surface. (3 pts.)
c) Describe in detail one of the features that Magellan revealed on the surface of Venus. (2)
29. Use the diagram below to answer the questions on this page. The diagram is “not to scale” and the view is looking down on the Earth from the North Pole.
a) Sketch the Moon in the space below as it would appear to you in College Park for position B. (What would you see?) (1)
b) The phase of the moon at position B is ______. (2)
c) When would the moon at position B set? (1)
d) If you were on the Moon at position B what would be the Earth’s phase? (2)
e) List any position(s) in the diagram where earthshine would be clearly visible. (2)
f) Describe why earthshine occurs. (2)
30. a) How is the greenhouse effect produced on Earth. Provide a clearly labeled sketch with written explanation at key points in your sketch. (5 pts.)
b) List the primary greenhouse gas and compare the surface atmospheric pressure on Earth and Venus. (4 pts.)
c) Why are the atmospheres of Venus and Earth very different? Explain what happened. (3 pts.)