Scale and History of the Universe
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Scale of Earth, Sun, Galaxy, and Universe
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Time Scale of the Cosmos
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Light and Fundamental Forces
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The Big Bang
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Expansion of the Universe
Stars, Black Holes, and Galaxies
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Life and Death of Stars
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Quasars and Galactive Collisions
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Stellar Parallax
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Cepheid Variables
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Our Galaxy: The Milky Way
Our Solar System
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The Sun
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The Planets
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Our Moon
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Components of the Solar System
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The Earth
Exploration of Space
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Space Travel History
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Rockets, Satellites, and Spaceships
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Future of Space Travel
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Space Missions
Introduction to Astronomy
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History of Astronomy
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Models of the Solar System
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History of the Telescope
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Astronomy Basics
Uncategorized Questions
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Anew planet is discovered in a different solar system. The new planet is much like Earth. One difference is that the planet does not have tides. What does the planet lack that Earth has?
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What is an asterism?
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How can constellations help modern sky watchers?
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Why do stars appear to move across the night sky?
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What is Polaris and where is it located?
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According to Copernicus, how do planets move?
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Are the stars in a constellation close together?
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Who named most of the constellations in the Northern Hemisphere?
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Should we devote time and money to building a space station on the moon or Mars? Why or why not?
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When Venus passes between the Earth and the sun, it is visible as a tiny black dot on the sun's bright disk. Why is Mars never visible in this same way?
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Would a year on Venus be longer or shorter than an Earth year?
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How is heliocentric longitude is used to show the position of planets in orbit around the Sun?
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What are the different theories of origin of the universe?
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Which stars are the brightest?
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Question #8c192
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What are the stages in the life cycle of an average star?
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If the gravitational forces of the sun on the planets suddenly disappeared, in what kind of paths would the planets move?
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What is stellar parallax and how is it measured?
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Why does the earth rotate counterclockwise?
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How do astronomers know the distance to moon?
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Question #9d794
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What evidence do scientists have that nothing existed before the Big Bang occurred?
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What is a trinary star system?
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How do temperature differences in the protoplanetary disk explain the arrangement of the planets in the solar system?
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Jupiter has sixteen satellites. What were the four largest ones discovered by Galileo?
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What is the Great Dark Spot on Neptune on?
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What is a constellation is and what determines when it is visible to us?
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What are the characteristics of a star?
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Question #ad198
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Question #1e7d2
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Question #c4b12
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In the motion called precession of the equinoxes, the Earth's axis of rotation precesses about the perpendicular to its orbital plane with a period of 2.58 104 yr. How would you calculate the torque on the Earth that is causing this precession?
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How would you explain earth's motion using the terms precession, rotation and revolution?
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Question #9e0e0
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How do you measure the masses of stars and planets?
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Question #02706
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Why do the planets appear to move through the constellations instead of with the constellations as Earth rotates?
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Question #956d1
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Question #619bf
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A thick atmosphere surrounds this planet. As a result, the temperature at its rocky surface is the hottest in the solar system. Which planet is it?
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A spectrograph is used to determine what characteristic of a star?
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Why might people continue to pursue space exploration in the future?
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If a star is moving away from the earth, toward which color will its visible light be shifted?
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Question #c9f34
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When two stars are bound together gravitationally and orbit a common mass, what are they known as?
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What is the cloud of interstellar dust and gas that forms a star is known as?
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What can scientists determine from the number of craters on a body?
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How many natural satellites does the earth have? What are their names?
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What are the colors of the stars from hottest to coldest?
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What is the advantage of a telescope in space over a ground based telescope?
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Why are objects in the solar system different from each other?
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Why can't astronomers measure the parallax of a star that is a million light-years away?
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What is the origin of the universe?
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What subjects, other than astronomy, would astronomers have to study in order to discover black holes?
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What would happen to a solar system if gravity suddenly stopped working?
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How do I become a a professional astronomer?
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What information did the Galileo space probe gather about Jupiter?
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Who was considered the greatest astronomical observer?
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Who postulated the elliptical orbits of the planet?
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How many stars have been observed in our solar system?
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Polaris is found in what constellation?
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How many constellations are in the Zodiac?
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What determines whether a star will eventually become a white dwarf or explode in a super nova?
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Why does the star Polaris have a higher absolute magnitude but the Sun has a higher apparent magnitude?
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Question #aaca0
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Question #87b8f
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When does a low-mass star become a giant star?
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Is there any kind of scientific consensus on whether or not space continues infinitely in all directions?
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Operational Iridium satellites orbit the earth at approximately what altitude?
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Question #dc422
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Question #e04e1
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What were some of Galileo's main contributions to science?
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How did Galileo's investigation of nature's laws differ from the people of his time?
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Question #ec6d0
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Some times, planets appear to be traveling clockwise, rather than counterclockwise, in their orbits. What is this motion called?
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On which planet is a day longer than a year?
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Which planet completes its rotation in 59-60 Earth days?
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Once a star is fully formed, it becomes which type of star?
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Why is the Sun different from other stars in the universe?
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What are characteristics of supergiants?
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Charon stays in the same place in Pluto's sky, but the moon moves across Earth's sky. What causes this difference?
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The elliptical galaxies are most like what part of our Milky Way?
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How are heavy elements formed?
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Which of the following has highest average density?
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Which of the following would be largest?
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If Kepler-452b is 1,400 light-years from Earth, and light travels at a speed approximately six trillion miles per year, how many miles away is Kepler-452b?
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Why is there no sound in space?
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Why does Earth have a liquid water supply and Mars does not?
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Why are large astronomical bodies such as planets and stars round?
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How did variations in the orbit of Uranus help scientists discover Neptune?
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Where in the solar system might scientists search for life, and why?
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Why can comets approach the Sun from any direction but asteroids generally orbit close to the plane of the elliptic?
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How did Galileo's observations of Jupiter and Venus support Copernicus's model?
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How did Kepler's theories further Copernicus' work?
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Saturn is approximately 1.5 billion kilometers from the sun. What is this distance in AU?
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Why is oxygen transported as a liquid in rocket instead of as a gas?
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Why do astronomers find it difficult to locate extrasolar planets with telescopes?
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How does the sun's gravitational attraction to the earth compare to that of the moon?
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How many stars are visible to the naked eye?
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As orbits get more "out of round" in shape, does eccentricity increase or decrease?