Download HW10 (due 4/24/14) (There are 205 possible points)

Name: ______________________
Class: _________________
Date: _________
ID: A
HW10 (due 4/24/14) (There are 205 possible points)
True/False (2 points each)
Indicate whether the statement is true or false.
____
1. It is theoretically possible for Earth to someday have a temporary ring structure.
____
2. Jupiter’s strong aurorae result from particles ejected by Io’s volcanoes.
____
3. The different cloud layers seen in Jupiter’s bands represent clouds at different altitudes.
____
4. Eruptions of water-powered geysers have been seen on the surface of Saturn’s moon Titan.
____
5. Jupiter’s mass is more than twice the mass of all the other planets in our Solar System combined.
____
6. In terms of the surfaces of moons, brighter surfaces usually indicate older surfaces.
____
7. Moons in retrograde orbits are called irregular moons.
____
8. Lakes of methane, ethane, and other hydrocarbons can be found on the surface of Saturn’s moon Titan.
____
9. Of the giant planets, only Saturn and Jupiter have ring systems.
____ 10. There are over 170 known moons in the Solar System.
Multiple Choice (5 points each)
Identify the choice that best completes the statement or answers the question.
____
1. When you look at the visible surface of a gas giant planet, you are looking at that planet’s _________.
a. oceans
d. metallic hydrogen
b. core
e. solid surface
c. atmosphere
____
2. The
a.
b.
c.
strongest magnetic fields in the Solar System are found on which planet?
Jupiter
d. Neptune
Saturn
e. Earth
Uranus
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Name: ______________________
ID: A
____
3. Uranus and Neptune are bluish green in color because they contain large amounts of:
a. ammonia
d. hydrocarbons
b. methane
e. oxygen
c. water vapor
____
4. Two years after first seeing them, Galileo found that Saturn’s rings vanished. What happened to them?
a. The old ring system dissipated, and since then a new one has formed.
b. The orbital plane of the rings was seen edge-on, and the rings were too thin to be
visible.
c. Most telescopes used hundreds of years ago couldn’t adequately resolve the ring
system.
d. Galileo was looking at the wrong planet, leading to the chance discovery of Uranus.
e. They were hidden behind some of Saturn’s many moons.
____
5. _________ has the most extreme seasons of any planet in the Solar System.
a. Jupiter
d. Neptune
b. Saturn
e. Earth
c. Uranus
____
6. Which of the following moons is thought to have a vast ocean of water beneath its frozen surface?
a. Triton
d. Io
b. Europa
e. Callisto
c. Ganymede
____
7. Large regular moons probably formed:
a. when passing asteroids were captured by the gravitational field of their planet
b. at the same time as their planets and grew by accretion
c. after a collision between a planet and an asteroid fractured off a piece of the planet
d. after the period of heavy bombardment in the early Solar System
e. after a planet got kicked out of its orbit and was gravitationally captured by another
planet
____
8. The
a.
b.
c.
____
only planet(s) without a moon is (are):
Mercury
d.
Venus
e.
Mars
Mercury and Venus
Mercury, Venus, and Mars
9. Why are Jupiter and Saturn not perfectly spherical?
a. They formed from the collision of two large planetesimals.
b. They rotate rapidly.
c. They have storms that develop preferentially along their equators.
d. They have very active aurorae that heat the atmospheres along the poles.
e. They have so much more gravity that the poles get pulled harder than the equators.
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Name: ______________________
ID: A
____ 10. Why do we find methane clouds above water clouds in the atmosphere of Saturn?
a. Methane clouds are less dense than water clouds.
b. Methane is far more plentiful than water on Saturn.
c. Methane is in a liquid/gas state at lower temperatures than water.
d. We can’t observe the methane clouds that are deeper in the atmosphere.
e. All of the above are good reasons.
____ 11. What is the angular diameter of Neptune if its diameter is 50,000 km and its distance is 30 AU?
a. 45 arcseconds
d. 10 arcseconds
b. 30 arcseconds
e. 2 arcseconds
c. 20 arcseconds
____ 12. Why aren’t all clouds on Jupiter white, like on Earth?
a. Jupiter’s clouds are made of methane.
b. Jupiter’s clouds are made of carbon dioxide.
c. There are chemical impurities in the ice crystals in Jupiter’s clouds.
d. The Sun is dimmer when viewed from Jupiter than when viewed from Earth.
e. For the same reason that we see colors in rainbows on Earth.
____ 13. The Great Red Spot, Jupiter’s most prominent storm system, has a diameter that is _________ times the
Earth’s diameter.
a. 2
d. 50
b. 5
e. 100
c. 10
____ 14. Of
a.
b.
c.
the giant planets, only Jupiter and Saturn have thick inner layers of:
liquid rock
d. liquid methane
solid rock
e. water
metallic hydrogen
____ 15. How does the thickness of Saturn’s bright ring system compare to its diameter?
a. It’s about 10 times thinner.
d. It’s about 100,000 times thinner.
b. It’s about 1,000 times thinner.
e. It’s about 10 million times thinner.
c. It’s about 10,000 times thinner.
____ 16. How do particles from the moon Enceladus wind up in Saturn’s E ring?
a. Volcanoes erupt and expel silicates into space.
b. Water geysers erupt from the surface and expel ice into space.
c. Cosmic rays bombard the surface rock on Enceladus and expel pieces into space.
d. A collision with a co-orbiting moon knocked rocky debris into orbit around Saturn.
e. Strong winds from Saturn blow material off of Enceladus’s surface.
____ 17. What measurement tells us that the interiors of Uranus and Neptune are made of mostly water?
a. their mass
d. their temperatures
b. their distance from the sun
e. their colors
c. their average densities
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Name: ______________________
ID: A
____ 18. Jupiter emits a large amount of radio emission because:
a. charged particles blasted off of Io’s surface move through Jupiter’s magnetic field
b. violent storms in its atmosphere produce a lot of lightening
c. Jupiter is so cold that its blackbody radiation peaks at radio wavelengths
d. Jupiter’s core has a very high temperature and pressure.
____ 19. The
a.
b.
c.
d.
e.
fact that Jupiter’s radius is contracting at a rate of 1 mm/year results in:
differential convection that powers Jupiter’s Great Red Spot
Jupiter’s rotation rate slowing down with time
Jupiter’s shape being less oblate
Jupiter radiating more heat than it receives from the Sun
Jupiter’s orbit around the Sun getting smaller
____ 20. Which of the following is FALSE?
a. The sizes of planetary ring material ranges from tiny grains to house-sized boulders.
b. Some rings around giant planets are made of particles that are ejected by its moons.
c. Planetary rings can be made when a moon is torn apart by tidal forces.
d. The material in planetary rings orbit the planet while obeying Kepler’s third law.
e. Planetary rings around the giant planets usually remain for tens of billions of years.
____ 21. Which object has turned itself inside out numerous times, leading to a situation where lighter elements
have escaped, sulfur compounds compose the crust, and primarily heavier elements make up its core?
a. Mercury
d. Pluto
b. Titan
e. Io
c. Callisto
____ 22. Which of the giant planets was predicted to exist mathematically before it was ever seen through a
telescope?
a. Jupiter
c. Uranus
b. Saturn
d. Neptune
____ 23. If you could find a large enough ocean, which one of these planets would float in it?
a. Uranus
d. Mars
b. Saturn
e. Earth
c. Neptune
____ 24. As
a.
b.
c.
a group, the giant planets all rotate _________ terrestrial planets.
faster than
d. retrograde compared to
slower than
e. sideways compared to
the same as
____ 25. Of
a.
b.
c.
what are Saturn’s ring primarily made?
water ice
methane
nitrogen
d.
e.
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dark organic material
dark silicate material
Name: ______________________
____ 26. The
a.
b.
c.
ID: A
colors of the cloud bands on Jupiter and Saturn are due primarily to differences in their:
wind speeds
d. temperatures
chemical compositions
e. densities
altitudes
____ 27. Io has the most volcanic activity in the Solar System because:
a. it is continually being bombarded with material in Saturn’s E ring
b. it is one of the largest moons and its interior is heated by radioactive decays
c. of gravitational friction caused by the moon Enceladus
d. its interior is tidally heated as it orbits around Jupiter
e. the ice on the surface creates a large pressure on the water below
____ 28. We
a.
b.
c.
d.
e.
refer to some of the inner regions of Jupiter and Saturn as metallic hydrogen because they:
are as dense as lead
are solid
provide support for the upper layers of hydrogen and helium
efficiently conduct electricity
are found in the core like iron is found at the core of the Earth
____ 29. How do astronomers take such detailed, close-up pictures of ring systems?
a. They send satellites to the outer planets to take pictures for us.
b. They take them using backyard telescopes, just like Galileo did.
c. They take them using the largest optical telescopes on Earth.
d. They have astronauts in space take pictures of them.
e. They wait until the planet is closest to the Earth and use the Hubble Space Telescope.
Short Answer (8 points each)
1. What causes the large magnetic fields of Uranus and Neptune? How does this source help explain why the
axis of their magnetic fields are misaligned and significantly offset from their rotational axes?
2. Compare the flux of sunlight at the Earth’s orbit to that at Saturn’s orbit. Note that Saturn’s average
distance from the Sun is 9.5 AU.
3. If Saturn’s rotational period is 11 hours and its radius is 6 × 107 m, what is the average speed of a cloud in
its atmosphere that is rotating with Saturn? (Neglect differential speeds due to winds.)
4. What are the orbital characteristics of a regular moon?
5. Calculate Jupiter’s mass (in Earth masses) based on its gravitational pull on its moon, Io, using Newton’s
version of Kepler’s third law: P2 = A3 /MJ. In order to do so, you will need the following information: Io’s
period = 1.769 days; Io’s semimajor axis = 422,000 km; the mass of the Sun = 2 × 103 0 kg; the mass of
Earth = 6 × 102 4 kg (also, 1 AU = 1.5 × 108 km).
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