Astronomy Ch. 13 Uranus and Neptune: The outer Worlds of the Solar System

The most abundant component of the atmospheres of Uranus and Neptune is: A) Hydrogen. B) Helium. C) Methane. D) Ammonia. E) Nitrogen.

Answer: A

Bands in Uranus' atmosphere, similar to those seen on the other jovian planets, A) form due to Uranus' rapid rotation. B) do not exist due to Uranus' large axial tilt. C) do not exist because Uranus is too small. D) are formed by interactions with Uranus' moons and rings. E) are driven by Uranus' internal energy source.

Answer: A

How were the rings of Uranus discovered? A) photometric observations of the occultation of a star made from Earth B) by Percival Lowell, who observed two "bumps" on either side of Uranus C) by William Herschel, while he also found the two largest moons D) by Voyager 2 when it passed by Uranus in 1986 E) by the Hubble Space Telescope in the infrared

Answer: A

In 1846, Johann Galle found Neptune: A) a few degrees from where it was predicted to be. B) after many years of searching for it. C) exactly where he predicted it would be. D) using just a pair of binoculars. E) using grossly inaccurate star charts.

Answer: A

Our most detailed knowledge of Uranus and Neptune comes from: A) spacecraft exploration. B) the Hubble Space telescope. C) ground based visual telescopes. D) ground based radio telescopes. E) manned missions.

Answer: A

Radiation darkening is a likely explanation of: A) why Uranus' moons are less reflective than Saturn's. B) the lack of distinct, visible bands in Uranus' atmosphere. C) Uranus' extreme axial tilt. D) the tilt of Uranus' magnetic field relative to the rotation axis. E) why Uranus' rings are so much fainter than Saturn's.

Answer: A

Studying the magnetospheres of the jovians has allowed us to measure their: A) rotation rates. B) orbital period. C) orbital radius. D) gravity. E) ring system diameters.

Answer: A

Uranus and Neptune appear bluish in color because: A) methane gas in their atmospheres absorbs red light well. B) ammonia absorbs blue light well. C) hydrogen and helium are both blue in large concentrations. D) dust motes in their atmospheres scatter blue well, just as in our own blue sky. E) from their distance, the Sun would appear hotter and bluer than from Earth.

Answer: A

What is the prediction for the future of Triton? A) It will provide the raw material for a future Neptunian ring. B) It will develop active volcanoes as Neptune's tidal stresses become greater. C) It will crash into Nereid when the smaller moon comes too close. D) Its orbit, while retrograde, is very stable and will not change. E) Its retrograde orbit will throw it back out into the Kuiper Belt again, with Pluto.

Answer: A

At the equator during the equinoxes on Uranus a day lasts: A) 7 hours. B) 8 hours. C) 21 years. D) 42 years. E) 84 years.

Answer: B

Compared with the other jovian planets, Neptune is: A) much larger and featureless. B) small with features similar to Jupiter. C) small and featureless. D) much larger with features similar to Saturn. E) average, but featureless.

Answer: B

In strength, the magnetic fields of Uranus and Neptune are: A) very different, with flopped over Uranus having no field, and Neptune a strong one. B) similar, with both about 100 times stronger than our own. C) even stronger than that of Jupiter. D) perfect fits for the Dynamo theory. E) like Jupiter and Saturn, due to mantles of liquid metallic hydrogen.

Answer: B

The clearest images of Uranus shown in the text have been obtained using: A) the Hubble Space Telescope. B) infrared ground- based telescopes at the Keck Observatory. C) the Pioneer Spacecraft. D) the Cassini Spacecraft. E) visible light ground-based telescopes at the European Southern Observatory.

Answer: B

The planet Uranus is: A) easily visible with the naked eye. B) barely visible with the naked eye. C) only visible with a small telescope or binoculars. D) only visible with a large, high quality telescope. E) only visible with a space-based telescope.

Answer: B

The rings of Uranus and Neptune are found: A) by the Hubble Space Telescope. B) above their equators. C) in the ecliptic plane. D) outside the Roche limit. E) All of the above.

Answer: B

What could explain the darker appearance of moons and rings in the outer solar system? A) They shine by the diminished light at that great distance from the Sun. B) They are made of small, sooty particles and radiation darkening with loss of volatile bright ices. C) They are composed of basaltic eject from the volcanism on Ariel and Triton. D) They are made of water ice that reflects light much more poorly at the very low temperatures of these moons. E) They are composed of mostly rocky material, like S type asteroids.

Answer: B

Which of the following is true about the seasons on Uranus? A) The seasons on Uranus are not unlike those on Earth or Mars. B) The Uranian rotation axis produces some extreme seasonal effects. C) Like Jupiter, Uranus has little tilt, with its equator always facing the Sun. D) From the Uranian equator, the Sun would remain stationary all the time. E) Uranus' weather will become less turbulent as equinox approaches in 2049.

Answer: B

Which of these is true about the seasons of Uranus? A) With a tilt of 29 degrees, they are not that different from our solstices and equinoxes. B) Its strange tilt produces extreme seasonal variations, especially at the poles. C) At the Uranian equator, the Sun would pass overhead every sixteen hours. D) At the Uranian pole the Sun sets every 16 hours during the summer and winter. E) There are no seasons at the poles.

Answer: B

William Herschel thought he had found a comet when he spotted the green disk of: A) Triton. B) Uranus. C) Neptune. D) Titania. E) Oberon.

Answer: B

About 50 years after Uranus was discovered: A) its rings were discovered. B) the retrograde motion of its orbit was observed. C) its orbit was too far off of its predicted path to be explained by observational errors. D) it was discovered that it had more natural satellites than any other planet. E) it was discovered that its atmosphere was featureless.

Answer: C

Although the atmospheres of Uranus and Neptune are very similar, the atmosphere of Neptune contains more: A) Hydrogen. B) Helium. C) Methane. D) Ammonia. E) Nitrogen.

Answer: C

In 1989, Neptune was found to have a huge storm named the: A) South Tropical Disturbance. B) Great Red Spot. C) Great Dark Spot. D) Hellas Basin. E) Galileo Regio.

Answer: C

In addition to Saturn's Titan, which other moon has a nitrogen atmosphere? A) Jupiter's Europa B) Uranus' Titania C) Neptune's Triton D) Jupiter's Ganymede E) Pluto's Charon

Answer: C

In terms of axial tilt, which of the jovians shows us the largest inclination? A) Jupiter B) Saturn C) Uranus D) Neptune E) Pluto

Answer: C

In the atmospheres of the jovian planets, this component increases, systematically, with distance from the Sun. A) Hydrogen B) Helium C) Methane D) Ammonia E) Nitrogen

Answer: C

Neptune and Uranus have a bluish tint because: A) at their distances, the Sun appears blue, the red absorbed by dust in the ecliptic. B) they are far away and distance makes objects appear bluish. C) their atmospheres contain methane, which absorbs red light. D) their atmospheres contain hydrogen and helium. E) ammonia ice reflects blue light better than any other color.

Answer: C

On which planet can the pole remain in darkness for 42 years, and then have 42 years of constant daylight? A) Jupiter B) Saturn C) Uranus D) Neptune E) Pluto

Answer: C

The magnetic field tilts of which two bodies are the most unusual? A) Mercury and Earth B) Jupiter and Saturn C) Uranus and Neptune D) Saturn and Venus E) Mars and Saturn

Answer: C

The planet Neptune is: A) easily visible with the naked eye. B) barely visible with the naked eye. C) visible with at least small telescopes or binoculars. D) only visible with a large, high-quality telescope. E) only visible with a space-based telescope.

Answer: C

The planet whose pole was facing the Sun when Voyager 2 approached in 1986 was: A) Jupiter. B) Saturn. C) Uranus. D) Neptune. E) Mars.

Answer: C

The rotation period of Uranus was measured through: A) observations of the motions of its satellites. B) observations of the features on its cloud surface. C) observations of radio signals associated with its magnetosphere. D) observations of its motion around the Sun. E) observations of Neptune's motion around the Sun.

Answer: C

The unique feature of Neptune is: A) that its rotational axis is tilted 98 degrees. B) that it rotates in a retrograde sense. C) that its atmosphere rotates more slowly than its interior. D) that it has no ring system. E) its banded cloud surface.

Answer: C

What is erupting out of the geysers on Triton? A) liquid water with basalt B) liquid methane with a dark hydrocarbon slush C) liquid nitrogen with carbon grit D) liquid carbon dioxide with graphite E) liquid hydrogen with dark helium ash

Answer: C

Which three played a role in the finding of Neptune? A) Herschel, Hubble, and Einstein B) Newton, Einstein, and Tombaugh C) Adams, Leverrier, and Galle D) Bode, Herschel, and Fraunhofer E) Shapley, Hubble, and Whipple

Answer: C

A day at the north pole of Uranus lasts: A) about 7 hours. B) about 8 hours. C) about 21 years. D) about 42 years. E) about 84 years.

Answer: D

Adams and Leverrier both predicted the position of Neptune, based on its effects on: A) the Sun. B) Jupiter. C) Saturn. D) Uranus. E) Pluto.

Answer: D

Adams and Leverrier predicted the position of Neptune, based on its perturbations of: A) Jupiter. B) the Sun. C) Saturn's rings. D) Uranus. E) Triton.

Answer: D

In the atmospheres of the jovian planets, this component decreases, systematically, with distance from the Sun. A) Hydrogen B) Helium C) Methane D) Ammonia E) Nitrogen

Answer: D

Small deviations in a planet's orbital motion: A) show we don't fully understand gravitational forces yet. B) indicate the presence of an extensive atmosphere. C) indicate the presence of a powerful magnetic field. D) imply the nearby presence of a massive body. E) show the planet's orbit isn't stable.

Answer: D

The masses of Neptune and Uranus were first determined by: A) observations of their motions around the Sun. B) observations of their magnetic fields. C) their densities divided by their volumes. D) observations of the motions of their satellites. E) their compositions.

Answer: D

The observed temperature difference between the northern and southern hemispheres of Uranus: A) is dozens of Kelvins. B) is hundreds of Kelvins. C) varies greatly. D) is about 10 Kelvin.

Answer: D

The only spacecraft to have visited Uranus and Neptune was: A) Pioneer 10. B) Pioneer 11. C) Voyager 1. D) Voyager 2. E) Cassini.

Answer: D

The time between equinoxes on Uranus is about: A) 7 hours. B) 8 hours. C) 21 years. D) 42 years. E) 84 years.

Answer: D

Unlike the atmospheres of Jupiter and Saturn, Uranus and Neptune have almost no: A) Hydrogen. B) Helium. C) Methane. D) Ammonia. E) Nitrogen.

Answer: D

Unlike the other jovian planets, Uranus: A) has no ring system. B) has only a few satellites. C) has a featureless atmosphere. D) has no internal energy source. E) rotates slowly.

Answer: D

Which of the Uranian moons displays the widest range of surface terrains, suggesting some catastrophic disruption? A) Puck B) Umbriel C) Oberon D) Miranda E) Ariel

Answer: D

Which planet had the Great Dark Spot in 1989, but had lost it by 1995? A) Jupiter B) Saturn C) Uranus D) Neptune E) Mars

Answer: D

Which statement about the magnetic fields of Uranus and Neptune is FALSE? A) Neither fits the Dynamo model very well. B) Uranus' field is tilted 60 degrees off its already tilted rotational axis. C) Neptune's field is tilted 47 degrees to its more conventional rotational axis. D) Both pass directly through the cores of their planets, like all other fields. E) Both may have ammonia water replacing the liquid metallic hydrogen.

Answer: D

Hubble Space Telescope photos have shown us: A) Uranus weather has produced more prominent patterns as equinox approaches. B) the Great Dark Spot of Neptune vanished in 1995. C) the rings of Uranus show up better in infrared than in visible light. D) Neptune still has more activity than Uranus, despite its distance from the Sun. E) All of the above are correct.

Answer: E

On Bode's advice, Herschel named his newly discovered planet after: A) the Greek god of the sea. B) the king of England. C) his benefactor. D) the Roman god of the underworld. E) the father of Saturn.

Answer: E

On what basis did Herschel think he had found a comet? A) The object appeared as a small greenish disk in his telescope. B) It appeared to be moving slightly night by night. C) No star appeared in that position on his charts. D) It was not a point of light, like a star should appear. E) All of the above are correct.

Answer: E

The rings of Neptune: A) were confirmed by the Voyager 2 in 1989. B) number five, with three narrow, two more diffuse. C) all lie within Neptune's Roche Limit. D) often appear as clumpy ring arcs, rather than complete and symmetrical. E) All of these are correct.

Answer: E

Uranus was discovered: A) by Galileo. B) thousands of years ago. C) with a radio telescope. D) after examining perturbations in Neptune's orbit. E) less than 250 years ago.

Answer: E

Uranus' large axial tilt is thought to be the result of: A) the same orbital irregularities that led to the discovery of Neptune. B) a single collision or impact event early in the solar system's history. C) the captures of one or more of Uranus' moons. D) giant planet migration. E) multiple catastrophic events, such as glancing collisions.

Answer: E