Astronomy Ch. 12 Saturn: Spectacular Rings and Mysterious Moons
A moon that goes inside the Roche Limit will: A) get heated by the strong magnetic fields. B) collide with a major satellite. C) escape its planet's gravity. D) be torn apart by the planet's tidal forces. E) become a planet.
Answer: A
Compared to Jupiter, Saturn's atmosphere is: A) more calm with fewer disturbances or storms. B) more uniform with no significant variation in color in the lower cloud levels. C) more violent with larger storm phenomena easily viewed from Earth. D) much thicker causing the visibility of the lower layers to be reduced. E) more colorful with variations in color easily viewed from Earth.
Answer: A
Compared to Jupiter, the motions observed in Saturn's atmosphere are: A) faster with fewer zone-belt alternations. B) slower with fewer zone-belt alternations. C) faster with more zone-belt alternations. D) slower with more zone-belt alterations. E) nearly identical.
Answer: A
Rhea, Saturn's second largest moon, might best be described as: A) having a very reflective, icy surface that is heavily cratered. B) orbiting in a highly elliptical orbit, far from Saturn. C) having the leading hemisphere six times darker than the following one. D) being composed of the densest material of any Saturnian moon and dark in appearance. E) being the only major moon of any planet not in synchronous rotation.
Answer: A
Saturn's bands, oval storm systems, and turbulent flow patterns are powered by: A) convective motion and rapid rotation. B) the Greenhouse Effect. C) a liquid metallic hydrogen interior. D) the fusion in Saturn's core. E) the tides of Titan.
Answer: A
The "wispy terrain" on Rhea was revealed by the Cassini spacecraft to be: A) ice cliffs created by tectonic fractures. B) water ice flows from past impacts that cracked its icy surface. C) the icy ash of water volcanoes. D) "maria" created during the period of high impacts. E) water ice flows from geyser-like activity.
Answer: A
The reason the rings of Saturn exist is because: A) the ring material lies within the Roche limit of Saturn. B) the gravitational influence of Titan confines them to those orbits. C) the eruptions of Mimas' volcanoes are keeping them supplied with ice. D) there has not been sufficient time for the ring particles to form a moon. E) Saturn's rapid rotation is spinning material away from its equator, out into space.
Answer: A
The wind speeds found in the bands and zones of Saturn, compared to those on Jupiter, are about: A) 3 times faster. B) 2 times faster. C) the same. D) 2 times slower. E) 3 times slower.
Answer: A
What makes Mimas a distinct moon? A) It suffered a huge meteorite impact that must have nearly shattered it. B) It helps maintain a wide apparent gap in Saturn's rings, known as Encke's Division. C) It has a rich atmosphere that may resemble that of the early Earth. D) It is the largest of Saturn's moons. E) The leading hemisphere is very dark, while the back side is bright ice.
Answer: A
1) If you could find a bathtub big enough for Saturn, the planet would: A) precipitate more helium. B) float. C) explode due to its liquid metallic hydrogen. D) catch fire, as liquid sodium reacts with water. E) sink due to its metallic interior.
Answer: B
Shepherd satellites are defined as: A) satellites in the coma of a comet. B) moons that confine a narrow ring. C) a type of moon that orbits another moon. D) moons that follow the exact orbit of another, larger, moon. E) moons that orbit inside the system of rings.
Answer: B
The most abundant element in Saturn's atmosphere is A) ammonia. B) hydrogen. C) helium. D) methane. E) nitrogen.
Answer: B
What did the Voyager mission discover about the Cassini Division? A) It actually contains one or more moons. B) It contains several ringlets. C) It is completely filled with a ring of very dark material. D) The spokes originate from it. E) It is actually completely empty of all ring material.
Answer: B
What evidence suggests that Enceladus has ongoing geological activity? A) Voyager 2 photographed liquid nitrogen geysers 10 kilometers tall. B) Lack of impact craters on much of its surface, evidence of ice flows from possible volcanic activity, and geysers that supply material for the E-ring. C) Voyager 1 showed sulfur eruptions all over its pizza-pie colored surface. D) Enceladus is located within Saturn's Roche limit, and ready to blow up. E) Enceladus undergoes severe tidal stresses from its resonance with Titan.
Answer: B
What mission landed on Titan in early 2005? A) Galileo's probe B) Huygens C) New Horizons D) Rover Spirit E) Cassini orbiter
Answer: B
Which of the following played the most important role in the ring's formation? A) Saturn's differential rotation B) Saturn's Roche limit C) Saturn's distance from the Sun D) debris from volcanoes on Mimas E) tidal resonance with Titan
Answer: B
Why are Saturn's rings so noticeable? A) They are made of metallic hydrogen. B) They are made of lots of fresh, bright icy particles from a recent breakup. C) The particles in the rings are highly polished from numerous collisions with other particles. D) They are made of nitrogen frost, like the bright surface of Triton. E) Saturn is so bright, the rings reflect a lot of light from both Saturn and the Sun.
Answer: B
Why do scientists think Titan has an atmosphere while the large moons of Jupiter (Ganymede, Callisto, Europa and Io) do not? A) The jovian satellites lost their atmospheres because of Jupiter's thermal radiation. B) The jovian satellites never formed atmospheres because the solar nebula was too hot there. C) The jovian satellites had their atmospheres stripped by Jupiter's gravitational pull. D) The jovian satellites experienced too many collisions in their lifetimes to maintain atmospheres. E) Titan got its atmosphere by accreting gases from Saturn. The jovian satellites were competing with one another to do this, so it was unsuccessful for any of them.
Answer: B
The Roche limit is the point at which: A) the mass of an object classifies it as a moon. B) a moon orbiting a planet experiences synchronous rotation. C) the external tidal forces on an object are strong enough to be felt by the object. D) the external tidal forces on an object become greater than the internal forces that hold it together. E) the internal forces that hold an object together weaken so that the object falls apart.
Answer: D
The reason Saturn lost very little of its original atmosphere is due to its: A) rapid rotation. B) strong magnetic field. C) ring system. D) large mass. E) many moons.
Answer: D
The shepherd moons keep the ring particles in their rings by: A) repelling the ring particles, causing them to slow down. B) repelling the ring particles, causing them to speed up or slow down. C) attracting the ring particles, causing them speed up. D) attracting the ring particles, causing them to speed up or slow down. E) both attracting and repelling the ring particles, causing them to speed up or slow down.
Answer: D
What is the space probe that is currently orbiting Saturn and is responsible for numerous discoveries of storms and weather patterns in Saturn's atmosphere called? A) Galileo B) Encke C) New Horizons D) Cassini E) Messenger
Answer: D
Why was it thought that Titan may have oceans of methane? A) Titan's atmosphere contains traces of methane. Similarly, Earth's atmosphere contains traces of water vapor. So, scientist thought Titan should have methane oceans. B) The atmospheric pressure at Titan's surface and its surface temperature are such that methane should be liquid on Titan's surface. C) The abundance of hydrocarbons in the atmosphere of Titan, led scientists to believe that Titan had an abundance of methane on its surface. D) Titan's atmosphere is like Earth's (mostly nitrogen), but its temperature is too low for water to be in the liquid phase. The only other possible liquid was methane. E) Since Saturn has methane ice in its atmosphere, methane should be abundant in this region of the solar system. The sheer abundance of methane in the region led scientists to hypothesize methane oceans on Titan.
Answer: B
At the surface of Saturn's atmosphere the strength of the magnetic field is: A) about the same as Mercury's magnetic field at its surface. B) about the same as Venus' magnetic field at its surface. C) about the same as Earth's magnetic field at its surface. D) about the same as Mars' magnetic field at its surface. E) about the same as Jupiter's magnetic field at its atmospheric surface.
Answer: C
Saturn is noticeably oblate because: A) it has strong magnetic fields that deform its shape. B) its powerful gravity acts stronger on the closer poles than the distant equator. C) it is a fluid body that is spinning rapidly. D) it is tidally distorted by the pulls for its satellite system. E) All of the above are correct.
Answer: C
The Cassini spacecraft found evidence that the E Ring is related to Enceladus through: A) the gravitational interactions by Enceladus on the particles in the E Ring. B) the deposition of gases from Enceladus on the particles of the E Ring making them more reflective as the gas condenses on the particles. C) a continual supply of icy particles spewed via volcanism on Enceladus. D) the impact history of Enceladus—a major impact caused parts of the moon to be ejected from the surface and cross the Roche Limit to become the E Ring. E) their common origin: both the E Ring and Enceladus have a common "ancestral" comet parent.
Answer: C
The asymmetrical surface markings on some of Saturn's moons are probably due to: A) all of the moons are located within the rings and they sweep up ring particles. B) the moons of Saturn are made primarily of ices. C) in most cases, the moons are tidally locked by Saturn's gravity into synchronous rotation. D) comet impacts become progressively harder as you get closer to Saturn. E) most of the moons show signs of ice volcanism driven by tidal interactions.
Answer: C
The atmosphere of Saturn is composed mostly of: A) methane and ammonia. B) carbon dioxide and ethane. C) hydrogen and helium. D) hydrogen sulfide and ammonia. E) nitrogen and oxygen.
Answer: C
Titan is an interesting moon because: A) beneath its clouds, Titan may be Earth-like, with liquid water. B) the Huygens rover has sent back images of sedimentary rocks there. C) it has a rich atmosphere that may resemble that of the early Earth. D) it is known to have ice volcanism on its surface. E) All of the above.
Answer: C
What did the Huygens and Cassini probes find on the surface of Titan? A) rocks and no water B) methane oceans C) an ocean and some lakes of methane, ethane, and other hydrocarbons D) lakes and oceans of water E) no methane, no water; just rocks
Answer: C
Which moon of Saturn constantly changes its rotational speed and rotational axis? A) Mimas B) Iapetus C) Hyperion D) Calypso E) Janus
Answer: C
While not yet observed in eruption, it is likely that ________ has active volcanoes; it certainly has one hemisphere greatly reworked by tectonic and volcanic forces. A) Dione B) Titan C) Enceladus D) Mimas E) Rhea
Answer: C
Why does Saturn radiate even more excess energy than Jupiter? A) Saturn is still radiating heat left over from its formation. B) Saturn's thick cloud layer contributes to a larger Greenhouse Effect. C) Helium rain gives off heat as it differentiates toward Saturn's center. D) Saturn's atmosphere contains much methane, creating a large Greenhouse Effect. E) Saturn can fuse hydrogen into helium in its core, like the Sun.
Answer: C
Cassini is the name of: A) the French astronomer who first discovered a gap in Saturn's rings. B) a gap in the rings created by a resonance with Mimas. C) NASA's orbiter now taking photos of Saturn. D) All of the above. E) None of the above.
Answer: D
How many large moons does Saturn have? A) 4 B) 3 C) 2 D) 1 E) 0
Answer: D
How many medium-sized moons does Saturn have? A) too many to count B) 18 C) 9 D) 6 E) 1
Answer: D
If satellite A is in a 2:1 resonance with satellite B, this means that: A) satellite A is twice as large as satellite B. B) satellite A moves twice as fast as satellite B. C) satellite A completes one orbit for every two orbits of satellite B. D) the orbit of satellite B takes twice as long to complete as that of satellite A. E) satellite B spins on its axis one time for every two orbits of satellite A.
Answer: D
Saturn's cloud surface appears more uniform than Jupiter's because: A) there is a thick outer cloud covering of water ice overlying the colorful ices. B) due to Saturn's lower gravity, the colorful cloud layers escaped. C) it is composed of completely different gases than Jupiter's. D) the cloud layers are thicker, allowing fewer holes to see the colorful layers. E) due to Saturn's greater distance from the Sun, the colorful cloud layers are just not visible.
Answer: D
Saturn's rings are edge-on and vanish when it is at: A) opposition. B) conjunction with the Sun. C) greatest elongation. D) equinox. E) solstice.
Answer: D
Scientists believe that large storms on Saturn are: A) tied to Saturn's rings. B) in the high altitude ammonia clouds. C) only found at the equator. D) rooted deep in the atmosphere. E) in Saturn's troposphere.
Answer: D
Shepherd moons were discovered because scientists hypothesized their existence after observing: A) the Cassini Gap. B) the spiral density waves in the ring system. C) that the gaps are not empty space, but low density regions of material. D) the narrow F Ring. E) the backlit E Ring.
Answer: D
When Voyager 2 was routed to fly by Saturn, it was originally the plan to have the satellite fly through the Cassini gap. Why would this have been a bad idea? A) That route would have taken Voyager 2 within the Roche Limit and the satellite would have been torn to pieces. B) That route would have taken Voyager 2 inside Saturn's magnetic field causing the electronics on board to be destroyed. C) The Cassini gap actually contains a large moon that orbits Saturn with a very high speed and Voyager 2 would have collided with that moon. D) The gaps in Saturn's ring system (including the Cassini gap) are not actually empty space, rather they are an area of low density in the rings. E) Voyager 2 would have encountered density waves which would have crushed the satellite.
Answer: D
Which Saturnian moon has the leading hemisphere black as tar, the back side icy white? A) Rhea B) Titan C) Enceladus D) Iapetus E) Mimas
Answer: D
While Galileo saw Saturn as a changing oval, the real nature of the rings was discovered by: A) Halley. B) Newton. C) Lowell. D) Huygens. E) Cassini.
Answer: D
Why does the atmosphere of Saturn appear to have only half the helium content of Jupiter? A) Because Saturn is so much colder, helium does not show up as strongly in its spectrum. B) Saturn was formed farther from the helium rich Sun. C) A red dwarf, Jupiter has fused some of its hydrogen into helium, whereas Saturn, a colder planet, has not. D) Much of Saturn's helium has differentiated towards its center. E) Much of Saturn's helium has reacted with water and formed helium oxide.
Answer: D
Saturn's rings are widest open, doubling the planet's brightness, when it is at: A) opposition. B) quadrature. C) greatest elongation. D) equinox. E) solstice.
Answer: E
The atmosphere of Titan is composed mostly of: A) oxygen. B) methane. C) carbon dioxide. D) hydrogen. E) nitrogen.
Answer: E
What are Saturn's rings? A) a great disk of liquid helium B) large rocky boulders moving in orbit around Saturn C) a glowing, flat magnetospheric auroral display D) a solid thin disk of material encircling Saturn E) small icy particles moving in orbit around Saturn
Answer: E
What did the Voyager mission discover about the main rings of Saturn? A) There are hundreds of small moons in the ring system. B) They were less dense than the rings of Jupiter. C) There are several small moons inside the inner-most ring. D) The ring system is much thicker than originally believed. E) They are composed of tens of thousands of narrow ringlets.
Answer: E
What is interesting about Saturn's large moon Titan? A) It is one of Saturn's two large moons. B) It has a 2:1 resonance with Mimas and a 4:1 resonance with the Cassini gap. C) It has its own moon. D) It orbits Saturn in a retrograde sense. E) It has an atmosphere.
Answer: E
Why do scientists think the Cassini spacecraft did not observe "spokes" on the rings during the first year of its visit with Saturn? A) The "spokes" observed before were a phenomenon of the Voyager 2 camera. B) The "spokes" are not a regular phenomenon of Saturn's rings. They occur only in certain seasons. C) The "spokes" are related to Saturn's magnetic field and the Cassini spacecraft was located inside Saturn's magnetic field, while Voyager 2 was not. D) The Cassini spacecraft was not looking in the right part of Saturn's ring system to see the "spokes". E) To see the "spokes," a particular alignment of the rings with the Sun is necessary and it took one year for that alignment to reoccur.
Answer: E
