EAPS 105: Homework 9

9.10. In Wikipedia, look up "Charon (moon)", read the intro and then scroll down to "Formation" and answer the following question: How did Pluto likely obtain Charon? A) From a giant impact B) From a circumplanetary disk. C) It was captured.

A) From a giant impact

9.17. In Wikipedia, look up "Rings of Saturn" and answer the following question: Which of the following is a primary cause of gaps in Saturn's rings? A) Gravitational influence of Saturn's many moon B) Collision from asteroids C) Saturn's large magnetic field D) The solar wind

A) Gravitational influence of Saturn's many moon

9.11. In Wikipedia, look up "Io (moon)", read the intro and then scroll down to "Orbit and rotation" and answer the following question: Why is Io in an elliptical orbit? A) It is in an orbital resonance with Europa and Ganymede. B) It interacts with Jupiter's magnetic field. C) It is not tidally locked. D) Its volcanic eruptions provide enough force to push it out of a circular orbit.

A) It is in an orbital resonance with Europa and Ganymede.

9.18. In Wikipedia, look up "Rings of Neptune" and answer the following question: Aside from Saturn, which of the other giant planets have rings? A) Neptune B) Uranus C) Jupiter D) All the above

D) All the above

9.12. In Wikipedia, look up "Rings of Saturn", read the intro and then scroll down to "Physical characteristics" and answer the following question: What are Saturn's rings made of? A) Rock B) Hydrogen C) Nitrogen ice D) Water ice

D) Water ice

9.4. In Wikipedia, look up "Io (moon)" and answer the following question: What is unique about Jupiter's moon Io compared to all other moons in the solar system? A) It has lakes on its surface. B) It is the only moon with a substantial magnetic field. C) It is the largest object in the Solar System that may not be properly differentiated. D) It was captured. E) It is the most volcanically active.

E) It is the most volcanically active.

9.8. In Wikipedia, look up "Titan (moon)" and answer the following question: What is unique about Saturn's moon Titan compared to all other moons in the solar system? A) It has lakes on its surface. B) It is the only moon with a substantial magnetic field. C) It is the largest object in the Solar System that may not be properly differentiated. D) It was captured. E) It is the most volcanically active.

A) It has lakes on its surface.

9.16. In Wikipedia, look up "Shepherd moon" and answer the following question: What is a shepherd moon? A) A celestial body that helps keep comets in their orbits around the sun. B) A moon that clears a gap in planetary-ring material or keeps particles within a ring contained. C) A moon that keeps another moon in an elliptical orbit via gravitational interactions. D) A moon that continuously changes orbits.

B) A moon that clears a gap in planetary-ring material or keeps particles within a ring contained.

9.3. In Wikipedia, look up "Galilean moons", read the intro and then scroll down to "Origin and evolution", and answer the following question: What is the theory regarding how Jupiter obtained its four largest moons, the Galilean moons? A) From a giant impact B) From a circumplanetary disk, a ring of accreting gas and solid debris around Jupiter analogous to a protoplanetary disk around a Sun. C) They were captured. D) From material ejected by a fast-spinning young Jupiter at a time when the planet was mostly rock and ice.

B) From a circumplanetary disk, a ring of accreting gas and solid debris around Jupiter analogous to a protoplanetary disk around a Sun.

9.5. In Wikipedia, look up "Ganymede (moon)" and answer the following question: What is unique about Jupiter's moon Ganymede compared to all other moons in the solar system? A) It has lakes on its surface. B) It is the only moon with a substantial magnetic field. C) It is the largest object in the Solar System that may not be properly differentiated. D) It was captured. E) It is the most volcanically active.

B) It is the only moon with a substantial magnetic field.

9.20. In Wikipedia, look up "Triton (moon)" and answer the following question: What will be the fate of Neptune's moon Triton? A) It will burn up along with the rest of the Solar System when the Sun becomes a red giant. B) It will cross the Roche limit and become a ring around Neptune. C) It will continue to move away from Neptune until it eventually leaves Neptune's orbit. D) It will eventually collide into Pluto.

B) It will cross the Roche limit and become a ring around Neptune.

9.13. In Wikipedia, look up "Rings of Saturn", read the intro and then scroll down to "Physical characteristics" and answer the following question: How big are the particles that make up Saturn's rings? A) Less than a 1 m B) Less than 10 m C) Less than 100 m D) Bigger than 100 m

B) Less than 10 m

9.1. In Wikipedia, look up "Giant-impact hypothesis", read the intro and then scroll down to "Basic model", and answer the following question: According to the basic model, which of the following is not an inferred characteristic of the collision that led to the formation of the Moon? A) The impactor was a Mars-sized object. B) The collision was a direct hit, not at an oblique angle. C) The impact material would have initially formed a disk of debris around the Earth before accreting into the Moon. D) All the above are characteristic of the collision that led to the formation of the Moon.

B) The collision was a direct hit, not at an oblique angle.

9.6. In Wikipedia, look up "Callisto (moon)" and answer the following question: What is unique about Jupiter's moon Callisto compared to all other large moons in the solar system? A) It has lakes on its surface. B) It is the only moon with a substantial magnetic field. C) It is the largest object in the Solar System that may not be properly differentiated. D) It was captured. E) It is the most volcanically active.

C) It is the largest object in the Solar System that may not be properly differentiated.

9.15. In Wikipedia, look up "Roche limit" and answer the following question: What happens to a moon if it migrates inside the Roche limit? A) It will be forced into a higher orbit by tidal forces. B) It will be crash into the planet. C) It will be pulled apart. D) It will become tidally locked.

C) It will be pulled apart.

9.2. In Wikipedia, look up "Giant-impact hypothesis" and answer the following question: Which of the following observations does the giant-impact hypothesis explain? A) Moon samples indicate that the Moon was once molten. B) The Moon has a relatively small iron core. C) The stable-isotope ratios of lunar and terrestrial rock are identical, implying a common origin. D) All the above

D) All the above

9.7. In Wikipedia, look up "Enceladus" and answer the following question: Enceladus is an icy moon of Saturn experiencing tidal forces because of an elliptical orbit due to an orbital resonance with another moon Dione. What are the consequences of tidal heating of Enceladus because of this elliptical orbit? A) A subsurface ocean B) Geysers C) Tectonically deformed terrains (cracked ice). D) All the above

D) All the above

9.9. In Wikipedia, look up "Triton (moon)", read the intro and then scroll down to "Capture" and answer the following question: Neptune is believed to have captured its largest moon Triton. What is the evidence? A) Moons in retrograde orbits (opposite the spin of the planet) cannot form in the same region of the solar nebula as the planets they orbit. B) Triton's eccentric orbit. C) Triton is nearly identical to Pluto in composition, suggested it originated from the Kuiper belt. D) All the above

D) All the above

9.19. In Wikipedia, look up "Iapetus (moon)", read the intro and then scroll down to "Equatorial ridge", and answer the following question: Why does Saturn's moon Iapetus have a bulge around its equator? A) It is the remnant of an oblate shape (stretched spherical shape) from a time when the moon spun very fast. B) Because a ring crashed down onto its surface. C) Icy material welled up along its equator. D) All the above have been suggested.

D) All the above have been suggested.

9.14. In Wikipedia, look up "Roche limit" and answer the following question: What is the Roche limit? A) The diameter of a moon required for its gravity to be strong enough to pull it into a spherical shape. B) The distance beyond which a ring will form around a planet due to tidal forces. C) The distance a moon can be from a planet without it drifting out of orbit. D) The distance from a celestial body within which a second celestial body will disintegrate because the first body's tidal forces exceed the second body's gravitational self-attraction.

D) The distance from a celestial body within which a second celestial body will disintegrate because the first body's tidal forces exceed the second body's gravitational self-attraction.