Astronomy – Chapter 11 – Flashcards
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Which of the following is not a general characteristic of the four jovian planets in our solar system?
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They are higher in average density than are the terrestrial planets.
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Which of the following statements comparing the jovian interiors is not thought to be true?
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They all have the same exact set of internal layers, though these layers differ in size.
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Overall, Jupiter's composition is most like that of
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the Sun.
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Jupiter's colors come in part from its three layers of clouds. Which of the following is not the primary constituent of one of Jupiter's cloud layers?
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clouds of sulfuric acid
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How do typical wind speeds in Jupiter's atmosphere compare to typical wind speeds on Earth?
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They are much faster than hurricane winds on Earth.
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What is the Great Red Spot?
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The Great Red Spot is a long-divided, high-pressure storm on Jupiter.
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What atmospheric constituent is responsible for the blue color of Uranus and Neptune?
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methane
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How does the strength of Jupiter's magnetic field compare to that of Earth's magnetic field?
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Jupiter's magnetic field is about 20,000 times as strong as Earth's.
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Which of the following statements about the moons of the jovian planets is not true?
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The majority of the moons are large enough to be spherical in shape, while only a few have the more potato-like shapes of asteroids.
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The most volcanically active body in our solar system is
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Io.
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Which moon has a thick atmosphere?
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Titan
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Which moon is considered likely to have a deep, subsurface ocean of liquid water?
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Europa
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Among all the large jovian moons, one is thought to have been captured into its present orbit rather than having formed in the "miniature solar nebula" that formed its planet. Which one?
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Triton
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Suppose you could float in space just a few meters above Saturn's rings. What would you see as you looked down on the rings?
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countless icy particles, ranging in size from dust grains to large boulders
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If Jupiter were scaled to the size of a basketball, Earth would be the closest to the size of
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a marble
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How many more times is the atmospheric pressure in Jupiter's core greater than the atmospheric pressure at Earth's surface?
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100 million
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How do astronomers think Jupiter generates its internal heat?
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by contracting, changing gravitational potential energy into thermal energy
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How do the size and mass of Jupiter's core compare to the size and mass of Earth?
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It is about the same size but is 10 times more massive.
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Why is Jupiter denser than Saturn?
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The extra mass of Jupiter compresses its interior to a greater extent than that of Saturn.
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Why is Neptune denser than Saturn?
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It has a different composition than Saturn, including a higher proportion of hydrogen compounds and rocks.
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How do the jovian planet interiors differ?
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All have cores of about the same mass, but differ in the amount of surrounding hydrogen and helium.
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Why do the jovian planet interiors differ?
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Accretion took longer further from the Sun, so the more distant planets formed their cores later and captured less gas from the solar nebula than the closer jovian planets.
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Why does Jupiter have several distinct cloud layers?
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Different layers represent clouds made of gases that condense at different temperatures.
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Why are there no impact craters on the surface of Io?
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Io did have impact craters but they have all been buried in lava flows.
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What mechanism is most responsible for generating the internal heat of Io that drives the volcanic activity?
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tidal heating
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Which of the following is not due to tidal forces?
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the retrograde orbit of Triton (a moon of Neptune)
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Which of the following statements about Titan is not true?
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It is the coldest moon in the solar system.
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Why are Saturn's rings so thin?
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Any particle in the ring with an orbital tilt would collide with the ring particles, flattening its orbit.
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Planetary rings are
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all of these
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What is the Cassini division of Saturn's rings?
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a large gap, visible from Earth, produced by an orbital resonance with the moon Mimas
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Jupiter and the other jovian planets are sometimes called "gas giants." In what sense is this term misleading?
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They really contain relatively little material in a gaseous state. Much more of their mass is liquid, metallic, or in strange high-pressure states that we don't naturally find on Earth.
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According to our theory of solar system formation, why did Uranus and Neptune end up to be much less massive than Jupiter and Saturn?
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Particles in the solar nebula were more spread out at greater distances, so that accretion took longer and there was less time to pull in gas before the solar wind cleared the nebula.
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Uranus and Neptune have methane clouds but Jupiter and Saturn do not. Which factor explains why?
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Temperatures on Jupiter and Saturn are too high for methane to condense.
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Which jovian planet should have the most extreme seasonal changes?
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Uranus
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Which of the following best explains why so many of the jovian moons have been more geologically active in the past than have the Moon or Mercury?
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Jovian moons are made mostly of ice that can melt of deform at much lower temperatures than can the rock and metal that make up the Moon and Mercury.
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Which of the following is not a piece of evidence supporting the idea that Europa may have a subsurface ocean?
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Astronomers have detected small lakes of liquid water on Europa's surface.
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Why do astronomers believe that Triton is a captured moon?
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Triton orbits Neptune in a direction opposite that of Neptune's rotation.