Astronomy Chapter 7 Test Questions – Flashcards
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How does the Sun's mass compare with that of the planets?
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It is a thousand times more massive than all the planets combined.
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Where does nuclear fusion occur in the Sun?
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in its core
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Which planet has the highest average surface temperature, and why?
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Venus, because of its dense carbon dioxide atmosphere
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The most metal-rich terrestrial planet is
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Mercury.
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Which planet, other than Earth, has visible water ice on it?
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Mars
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Pluto is different from the outer planets in all of the following ways except which one?
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Its surface temperature is very cold.
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Which of the following is farthest from the Sun?
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a comet in the Oort cloud
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Which of the following observations indicates that conditions on Mars may have been suitable for life in the past?
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There are dried-up riverbeds on Mars.
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Which planet has a ring system?
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A) Jupiter B) Saturn C) Uranus D) Neptune
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What is the primary reason why a Pluto flyby mission would be cheaper than a Pluto orbiter?
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The fuel needed for an orbiter to slow down when it reaches Pluto adds a lot of weight to the spacecraft.
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What is aerobraking?
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the technique of using a planetary atmosphere to change the orbit of a spacecraft
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Which of the following is not an advantage of spacecraft flybys over ground-based telescope observations?
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Spacecraft can monitor changes in a planet's atmosphere over long times.
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Which of the following statements is not an observed pattern of motion in our solar system?
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Most planets orbit at the same speed.
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Which of the following is not an exception to the general patterns in the solar system?
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the rings of Saturn
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Which is the densest planet in the solar system?
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Earth
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The planet closest in size to Earth is
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Venus.
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Which of the following is not a characteristic of the inner planets?
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They all have substantial atmospheres.
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Which of the following is not a characteristic of the outer planets?
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They have very few, if any, satellites.
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What are the main constituents of the jovian planets?
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hydrogen and helium
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Where are most of the known asteroids found?
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between the orbits of Mars and Jupiter
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How do asteroids differ from comets?
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Asteroids are rocky bodies and are denser than the comets, which are made of icy material.
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Based on the frequency with which we see comets from Earth, astronomers estimate the total number of comets in the solar system to be
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1 trillion.
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Which of the following best describes Pluto in terms of the general characteristics of terrestrial and jovian planets?
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size and solid surface similar to terrestrial planets; distance similar to jovian planets
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Astronomers have decided that, rather than being a planet, Pluto is really just a large member of
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the Kuiper belt.
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Which of the following is not a pattern of motion in our solar system?
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Planets all rotate in the same direction.
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Suppose you view the solar system from high above Earth's North Pole. Which of the following statements about planetary orbits will be true?
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All the planets orbit counterclockwise around the Sun.
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The terrestrial planets in our solar system are
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Mercury, Venus, Earth, and Mars.
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The jovian planets in our solar system are
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Jupiter, Saturn, Uranus, and Neptune.
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When we say that jovian planets contain significant amounts of hydrogen compounds, we mean all the following chemicals except
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carbon dioxide.
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Which of the following statements about the asteroid belt is not true?
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The combined mass of all the asteroids is roughly the same as the mass of Earth.
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What is the Kuiper belt?
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a region of the solar system beginning just beyond the orbit of Neptune that contains many icy comets
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What is the Oort cloud?
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It is not really a cloud at all, but rather refers to the trillion or so comets thought to orbit the Sun at great distances.
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Which of the following statements about our Sun is not true?
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The Sun's diameter is about 5 times that of Earth.
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Which of the following is not true of Mercury?
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It has been studied closely by several NASA spacecraft.
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Which of the following statements about Mars is not true?
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We could survive on Mars without spacesuits, as long as we brought oxygen in scuba tanks.
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The planet in our solar system with the highest average surface temperature is
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Venus.
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Which jovian planet does not have rings?
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All the jovian planets have rings.
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Which moons are sometimes called the Galilean moons?
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the four largest moons of Jupiter: Io, Europa, Ganymede, and Callisto
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Which of the following statements about Pluto is not true?
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It is the largest known object that is considered to be a dwarf planet.
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The Cassini mission to Saturn consists of
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an orbiter that orbits Saturn and a probe that descended to the surface of Titan.
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Which planet (besides Earth) has been visited by the largest number of robotic spacecraft?
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Mars
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Which of the following is not a major pattern of motion in the solar system?
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Nearly all comets orbit the Sun in same direction and roughly the same plane.
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Which of the following is not a major difference between the terrestrial and jovian planets in our solar system?
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Terrestrial planets contain large quantities of ice and jovian planets do not.
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Consider the following statement: "Rocky asteroids are found primarily in the asteroid belt and Kuiper belt while icy comets are found primarily in the Oort cloud." What's wrong with this statement?
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The Kuiper belt contains icy comets, not rocky asteroids
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Which of the following is not a real difference between asteroids and comets?
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Asteroids orbit the Sun while comets just float randomly around in the Oort cloud.
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The following statements are all true. Which one counts as an "exception to the rule" in being unusual for our solar system?
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The diameter of Earth's Moon is about 1/4 that of Earth.
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Compared to the distance between Earth and Mars, the distance between Jupiter and Saturn is
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much larger.
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How is Einstein's famous equation, E= mc2, important in understanding the Sun?
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It explains the fact that the Sun generates energy to shine by losing some 4 million tons of mass each day.
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Venus has a higher average surface temperature than Mercury. Why?
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because its surface is heated by an extreme greenhouse effect
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In what way is Venus most similar to Earth?
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Both planets are nearly the same size.
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Which of the following statements about the recently-discovered object Eris is not true?
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It is thought to be the first example of a new class of object.
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Mars has two moons that are most similar in character to
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small asteroids.
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Imagine that an alien spaceship crashed onto Earth. Which statement would most likely be true?
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It would crash in the ocean.
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Which planet listed below has the most extreme seasons?
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Uranus
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In what way is Pluto more like a comet than a planet?
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It is made mostly of rock and ice.
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Why was it advantageous for the Voyager mission to consist of flybys rather than orbiters?
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Each individual spacecraft was able to visit more than one planet.
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Why has NASA sent recent orbiters to Mars on trajectories that required them to skim through Mars's atmosphere ("aerobraking") before settling into their final orbits?
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It saved money because the spacecraft used atmospheric drag to slow down rather than needing to carry enough fuel to slow by firing rocket engines.
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Hubble Space Telescope
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earth orbiter
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the main part of the Galileo spacecraft (i.e., not its atmospheric probe)
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planetary orbiter
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Curiosity
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lander
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voyager 2
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flyby
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visited all four giant planets between 1979 and 1989
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voyager 2
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mapped most of the surface of Venus with radar observations from Venusian orbit
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magellan
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carried the first humans to the Moon on July 20, 1969
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Apollo II
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dropped a probe into Jupiter on December 7, 1995
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Galileo
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landed on mars in 1976
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Viking 1,2
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used a sky crane to lower itself to the surface of Mars
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curiosity
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carried a probe that landed on Titan
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cassini
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is soon to become the first spacecraft to fly by Pluto
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new horizon
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has been collecting high-resolution images of Jupiter and its moons since 1995
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Galileo Orbiter
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is currently in orbit around Saturn
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Cassini
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the only spacecraft listed that remains in Earth's orbit
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Hubble Space telescope
