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12 Cards in this Set
- Front
- Back
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Milky Way Galaxy
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The Sun and all objects that orbit around it (planets and their moons, rocky asteroids and icy comets)
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Earth-centered universe
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geocentric
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How many stars are in a galaxy? How many stars are in our galaxy?
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~few hundred million to a trillion+
~more than 100 billion |
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Our solar system is located over halfway from the ___?
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galactic center
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Universe to the earth
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universe, local supercluster, local group, milky way galaxy, solar system, earth
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The early universe contained only 2 chemical elements: ___ and ___
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hydrogen and helium
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Our Milky Way is one of the 2 largest among about __ galaxies in the Local Group
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40
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Galaxy clusters
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groups of galaxies w more than a few dozen members
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Universe
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sum total of the matter and energy, encompassing the superclusters and voids and everything within them
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According to scientists, when did the Big Bang occur?
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14 billion years ago
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When is a star technically born and when does it die?
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~the center becomes dense enough and hot enough to generate energy by nuclear fusion
~dies when exhausts all its usable fuel |
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supernovae
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star dies in titanic explosion
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