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Questions about the early phases of the star formation process. A protostar is a large mass of gas that results of the contraction of a molecular cloud.
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a disk-shaped belt of icy debris orbiting in the outer solar system, lying beyond the orbit of Neptune and extending to a distance of about 50 astronomical units, containing thousan…
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Questions about the "adulthood" of stars. The main sequence is a distinctive band of stars that appears in a color-magnitude plot (known as Hertzsprung-Russell diagram). Stars appear in the main seque…
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Late Heavy Bombardment; occurring between 3.7-4 billion years ago when the inner solar system underwent heavy asteroidal impacts. Also know as the Lunar Cataclysm.
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Questions regarding undesired brightening of the night sky inhibiting observation of astronomical objects.
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Questions about gas-giant planets in very close orbit to their parent star (closer than Mercury).
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Questions about Europa, a moon of Jupiter with a planet-wide ocean under a thick ice crust.
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