Astronomy 1040 uvu final – Flashcards
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Which of the following statements does not use the term light-year in an appropriate way?
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It will take me light-years to complete this homework assignment.
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Which of the following correctly describes the concept of galactic recycling?
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New stars are continuously being formed in the Milky Way out of gas that has been ejected from a previous generation of stars.
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Our solar system consists of .
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the Sun and all the objects that orbit it
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An astronomical unit (AU) is .
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the average distance between Earth and the Sun
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Which of the following has your "cosmic address" in the correct order?
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you, Earth, solar system, Milky Way Galaxy, Local Group, Local Supercluster, universe
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When we look at an object that is 1,000 light-years away, we see it .
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as it was 1,000 years ago
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Why do the patterns of the stars in our sky look the same from year to year?
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because the stars in the constellations are so far away
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What is a circumpolar star?
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a star that always remains above your horizon
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What effect or effects would be most significant if the Moon's orbital plane were exactly the same as the ecliptic plane?
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Solar eclipses would be much more frequent.
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If the Moon is relatively far from Earth, so that its umbra does not reach Earth, someone directly behind the umbra will see
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an annular eclipse
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Which of the following never goes in retrograde motion?
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the Sun
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Which of the following statements about stellar parallax is true?
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The closer a star is to us, the more parallax it exhibits.
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Has Polaris always been the "North Star"?
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No, because the Earth's axis slowly changes the direction it points
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If the Moon is 3rd quarter phase, when does it rise?
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midnight
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"Gibbous" means a nearly full moon. If I see a waxing gibbous moon tonight, what moon phase will I see in one week?
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waning gibbous
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Which of the following correctly describes the meridian in your local sky?
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a half-circle extending from your horizon due north, through your zenith, to your horizon due south
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Which of the following best describes why we have seasons on Earth?
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The tilt of Earth's axis causes different portions of the Earth to receive more or less direct sunlight at different times of year.
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He discovered that the orbits of planets are ellipses.
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Kepler
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Which of the following statements about scientific theories is not true?
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A theory cannot be taken seriously by scientists if it contradicts other theories developed by scientists over the past several hundred years.
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Which of the following claims cannot be tested by science?
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The Earth was created by God.
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When Copernicus first created his Sun-centered model of the universe, it did not lead to substantially better predictions of planetary positions than the Ptolemaic model. Why not?
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Copernicus used perfect circles for the orbits of the planets.
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Which of the following is the reason for the solar day being longer than a sidereal day?
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the combined effect of the rotation of Earth and its orbit about the Sun
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Which of the following statements about scientific models is true?
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A model can be used to explain and predict real phenomena.
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During the time that a planet is in its period of apparent retrograde motion
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over many days or weeks, the planet moves westward relative to the stars, rather than the usual eastward relative to the stars
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What do astronomers mean by a constellation?
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A constellation is a region in the sky as seen from Earth.
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Newton's second law states: net force = mass x acceleration. According to this, what property can you determine if you observe the acceleration of an object with a known mass?
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the sum total of all forces acting on the object
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Which of the following objects is not a thermal emitter?
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Hot, thin gas
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At which lunar phase(s) are tides least pronounced (e.g., the lowest high tides)?
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both first and third quarters
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Which of the following describes the light that can be detected from a person?
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The person reflects many wavelengths of visible light and emits a continuum of wavelengths of infrared light.
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Doppler shifted hydrogen absorption lines are seen in the spectrum of a star. The hydrogen line at 656.28 nm is seen to be shifted to 656.08 nm. Is the star moving towards or away from us, or can we not tell?
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Moving toward us
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The astronauts feel weightless in the International Space Station, which orbits the Earth once every 90 minutes. Why?
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because they and the space station are both falling around the Earth
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Suppose you are in an elevator that is traveling upward at constant speed. How does your weight compare to your normal weight on the ground?
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It is the same.
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Consider the elliptical orbit of a comet around the Sun. Where in its orbit does it have the largest amount of total orbital energy?
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It is always the same orbit energy
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Consider the elliptical orbit of a comet around the Sun. Where in its orbit does it have the largest amount of total orbital energy?
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It always has the same total orbital energy.
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From lowest energy to highest energy, which of the following correctly orders the different categories of electromagnetic radiation?
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radio, infrared, visible light, ultraviolet, X-rays, gamma rays
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Which of the following observational techniques is most appropriate for measuring Doppler shifts?
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spectroscopy (taking a spectrum)
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If a material is transparent, then it
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Transmits light well
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One star is emitting primarily visible light and another star is emitting primarily infrared light. Which star is hotter?
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The star admitting visible light
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Imagine another solar system, with a star of the same mass as the Sun. Suppose a planet with a mass twice that of Earth (2MEarth) orbits at a distance of 1 AU from the star. What is the orbital period of this planet?
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1 year
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Which of the following is not an advantage of the Hubble Space Telescope over ground-based telescopes?
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It is closer to the stars
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Suppose you kick a soccer ball straight up to a height of 10 meters. Which of the following is true about the gravitational potential energy of the ball during its flight?
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The ball's gravitational potential energy is greatest at the instant when the ball is at its highest point.
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Which of the following is always true about images captured with X-ray telescopes?
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They are always shown with colors that are not the true colors of the objects that were photographed.
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The difference between speed and velocity is that .
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velocity also includes a direction
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The mass of Jupiter can be calculated by
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measuring the orbital period and distance of one of Jupiter's moons.
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Which of the following wavelength regions cannot be studied with telescopes on the ground?
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Ultraviolet and xray
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A net force acting on an object will always cause a change in the object's .
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Momentum
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What would happen if the Space Shuttle were launched with a speed greater than Earth's escape velocity?
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It would travel away from Earth into the solar system.
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Which of the following is a good reason to place observatories on remote mountain tops?
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to reduce atmospheric distortion and to reduce light pollution
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Which of the following statements about X-rays and radio waves is not true?
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X-rays travel through space faster than radio waves.
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The force due to gravity between two objects can be described using the equation Fg = G M1M2 d 2 . According to this equation, if the mass of the second object were greater, what happens to the gravitational force between them?
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The force increases
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Blue light hitting a red sweatshirt is an example of
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Absorbtion
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What do astronomers mean by light pollution?
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Light pollution is light from human sources that makes it difficult to see the stars at night
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Considering Einstein's famous equation, E = mc2 , which of the following statements is true?
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A small amount of mass can be turned into a large amount of energy.
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Which of the following objects would be most likely to produce an emission-line spectrum?
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A neon light
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Suppose that two objects collide. Which of the following things is not the same both before and after the collision?
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The total temperature of the object
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Which of the following properties cannot be determined from a spectrum of a star?
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speed perpendicular to my line of sight and chemical composition
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What does temperature mean
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the average kinetic energy of particles in a substance
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Which of the following represents a case in which you are not accelerating?
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Driving in a straight line at 60mph
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Which of the following statements best describes the two principle advantages of telescopes over eyes?
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Telescopes can collect far more light with far better angular resolution.
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Which of the following statements is not one of Newton's Laws of Motion?
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What goes up must come down
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The frequency of a wave is
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the number of peaks passing by any point each second. And measured in cycles per second. And measured in hertz (Hz). And equal to the speed of the wave divided by the wavelength of the wave
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Newton showed keplers laws are
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natural consequences of the law of universal gravitation
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As an interstellar cloud of hydrogen gas shrinks in size, its temperature increases
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because gravitational potential energy is converted to thermal energy.
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The fact that Voyager 10 continues to speed out of the solar system, even though its rockets have no fuel, is an example of
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Newton's first law of motion
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When considering light as made up of individual "pieces," each characterized by a particular amount of energy, the pieces are called
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Photons
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Tidal friction caused by Earth's stretching from the Moon's gravity is gradually
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slowing down the rotation of earth and increasing the orbital distance of the Moon
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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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What is the transit method of finding extrasolar planets?
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monitoring a star to detect periodic dips in its brightness from the planet passing in front of the star
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When we see a meteor shower, it means that .
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Earth is crossing the orbit of a comet
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Suppose that large jovian planets had never formed in our solar system. Which of the following would most likely be true?
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Neither the asteroid belt nor Oort cloud would exist.
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Which statement is not thought to be true of all comets in our solar system?
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Comets always have tails.
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What is the importance of the carbon dioxide (CO2) cycle?
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It regulates the carbon dioxide concentration of our atmosphere, keeping temperatures moderate.
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If the polar ice decreases, what would happen, and why?
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warming, because more sunlight is absorbed
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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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Earth has been gradually warming over the past few decades. Based on a great deal of evidence, scientists believe that this warming is caused by .
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human activities that are increasing the concentration of greenhouse gases in Earth's atmosphere
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What's the fundamental reason that Mars, unlike the Earth, has become virtually geologically dead?
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its small size compared to Earth
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What kind of thermal radiation does the Earth emit?
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infrared light
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Rank these planets in order of the strength of the greenhouse effect on the planet, from the least to the greatest.
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Mercury, Mars, Earth, Venus
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In science fiction movies, spaceships are often shown dodging through large numbers of closely spaced, boulder-size objects. Which of the following real things in our solar system would look most like such science fiction dangers?
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the rings of Saturn
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There are no auroras on Venus because it
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lacks a strong magnetic field.
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What do asteroids and comets have in common?
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Most are unchanged since their formation in the solar nebula.
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Which of the following applies to Europa?
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thought to have a deep, subsurface ocean of liquid water
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According to current evidence, Pluto is best explained as .
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a large member of the Kuiper belt
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Why do we think Mercury has so many tremendous cliffs?
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They were probably formed by tectonic stresses when the entire planet shrank as its core cooled.
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Why does Jupiter have three distinct layers of clouds?
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The three layers represent clouds made of gases that condense at different temperatures.
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Which of the following describes impact cratering?
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the excavation of bowl-shaped depressions by asteroids or comets striking a planet's surface
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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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What are the two primary methods by which planets have been found around other stars in our galaxy?
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Indirectly by detecting the motion of the host star AND Indirectly by measuring the drop in brightness of the host star when the planet crosses our line
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What do we mean by the frost line when we discuss the formation of planets in the solar nebula?
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It is a circle at a particular distance from the Sun, beyond which the temperature was low enough for ices to condense.
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According to our present theory of solar system formation, which of the following best explains why the solar nebula ended up with a disk shape as it collapsed?
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It flattened as a natural consequence of collisions between particles in the nebula.
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According to our present theory of solar system formation, which of the following lists the major ingredients of the solar nebula in order from the most abundant to the least abundant?
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hydrogen and helium gas; hydrogen compounds; rock; metal
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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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Which internal heat source still generates heat within the terrestrial worlds today?
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heat from radioactive decay
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How do scientists determine the age of the solar system?
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radiometric dating of meteorites
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According to current understanding, which of the following is required in order for a planet to have rings?
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The planet must have many small moons that orbit relatively close to the planet in its equatorial plane.
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The core, mantle, and crust of a planet are defined by differences in their
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density.
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Which of the following does not have a major effect in shaping planetary surfaces?
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magnetism
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According to our basic scenario of solar system formation, why do the jovian planets have numerous large moons?
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As the growing jovian planets captured gas from the solar nebula, the gas formed swirling disks around them, and moons formed from condensation accretion within these disks.
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If we could put all the asteroids together, their total mass would be .
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much less than the mass of any terrestrial planet
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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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All the following statements about Mars are true. Which one might have led to a significant loss of atmospheric gas to space?
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Mars lost any global magnetic field that it may once have had.
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Why did the solar nebula heat up as it collapsed?
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As the cloud shrank, its gravitational potential energy was converted to thermal energy.
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Volcanism is more likely on a planet that
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has high internal temperatures.
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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 of the following is not a characteristic of the inner planets?
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They all have substantial atmospheres.
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The maximum mass of a white dwarf is .
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about 1.4 times the mass of our Sun
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How is the lifetime of a star related to its mass?
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More massive stars live much shorter lives than less massive stars.
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The intricate patterns visible in an X-ray image of the Sun generally show .
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extremely hot plasma flowing along magnetic field lines
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Where would a brown dwarf be located on an H-R diagram?
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below and to the right of the lowest part of the main sequence
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Suppose you drop a clock toward a black hole. As you look at the clock from a high orbit, what will you notice?
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Time on the clock will run slower as it approaches the black hole, and light from the clock will be increasingly redshifted.
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Identify the correct sequence of life events for a high mass star.
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main sequence, red supergiant, supernova, neutron star
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The white dwarf that remains when our Sun dies will be mostly made of .
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Carbon
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Why does the Sun emit neutrinos?
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Fusion in the Sun's core creates neutrinos.
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You observe a star and you want to plot it on an H-R diagram. You will need to measure all of the following, except the star's .
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mass
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A star with a parallax angle of 1/20 arcsecond is .
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20 parsec away
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Energy balance in the Sun refers to a balance between
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the rate at which fusion generates energy in the Sun's core and the rate at which the Sun's surface radiates energy into space
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The Schwarzschild radius of a black hole depends on
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only the mass of the black hole
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Which is more common: a star blows up as a supernova, or a star forms a planetary nebula/white dwarf system?
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Planetary nebula formation is more common.
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Which process is required to allow a gravitationally-collapsing gas cloud to continue to collapse?
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The cloud must radiate much of its thermal energy.
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Which method of energy generation provides the source of energy for a protostar?
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gravitational contraction
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How is the sunspot cycle directly relevant to us here on Earth?
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Coronal mass ejections and other activity associated with the sunspot cycle can disrupt radio communi-cations and knock out sensitive electronic equipment.
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. When we see X-rays from an accretion disk in a binary system, we can't immediately tell whether the accretion disk surrounds a neutron star or a black hole. Suppose we then observe each of the following phenomena in this system. Which one would rule out the possibility of a black hole?
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intense X-ray bursts that last only a few seconds
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Why is a 1 solar-mass red giant more luminous than a 1 solar-mass main sequence star?
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The red giant is producing energy at a greater rate.
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. Degeneracy pressure stops the crush of gravity in all the following except
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a very massive main-sequence star.
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How do we test our computer models for the interior of the Sun?
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comparing model predictions to how the Sun actually vibrates
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What is the approximate range of masses that newborn main sequence stars can have?
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0.1 to 300 solar masses
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From center outward, which of the following lists the "layers" of the Sun in the correct order?
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core, radiation zone, convection zone, photosphere, chromosphere, corona
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Which of the following is not true about differences between novae and supernovae?
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Supernovae eject gas into space, but novae do not.
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Order these objects by size (radius) from smallest to largest:
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3 solar mass black hole, 3 solar mass neutron star, 0.5 solar mass white dwarf, 1 solar mass white dwarf.
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Which method of energy generation is used by the Sun today?
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H fusion by the proton-proton chain
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What observations characterize solar maximum?
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There are many sunspots visible on the surface of the Sun.
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Which star is the hottest star?
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O
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Which of the following statements about the Sun is an inference from a model, not an observation?
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The convection zone is cooler than the radiation zone.
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Where does gold (the element) come from?
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It is produced during the supernova explosions of high-mass stars.
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Why do sunspots appear dark?
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They are regions that are significantly cooler than the rest of the photosphere.
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. On a Hertzsprung-Russell diagram, where would you find red giant stars?
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upper right
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Which statement about pulsars is not thought to be true?
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Pulsars can form only in close binary systems.
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What is a helium flash?
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the sudden onset of helium fusion in the core of a low-mass star
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Which of the following terms is given to a pair of stars that appear to change position in the sky, indicating that they are orbiting one another?
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visual binary
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Which of the following is the phase of matter in the Sun?
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plasma
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What is a scientific theory?
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A synthesis of a large amount of information that encompasses well-tested hypotheses about certain aspects of the natural world.
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You are carrying a heavy couch through a doorway to help your neighbors move. However, the doorway is too narrow and your hand is between the door frame and the couch as it hits and comes to a stop. The concept that most explains why your hand is hurt is
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Inertia
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An object in free fall (no air resistance) undergoes an increase in
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Speed
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Which has zero acceleration? An object
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at rest. moving at constant velocity. in mechanical equilibrium.
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If a constant net force acts on an object,
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It's velocity changes
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Two teams pull on a rope in a tug-of-war. Each team pulls with a 300 N force. What is the tension in the rope?
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300
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The rotational inertia of an object is greater when most of the mass is located
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Away from the rotational acis
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Which moves faster in m/s on a merry-go-round: a horse on the inside near the center or a horse on the outside near the outer rail?
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Outside horse
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A large and a small person wish to parachute at equal terminal velocities. The larger person will have to
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Get a larger parachute
