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Question
What is meant by the idea life on Earth had an "interstellar origin"?Answer
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Related questions
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Describe the reasoning leading to the idea that the number of technological civilizations in the galaxy is equal to the average lifetime of a technological civilization.
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A galaxy with a blueshift is moving ________ Earth.
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The Tully-Fisher relation uses the rotational speed of the galaxy to measure its ________.
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Hubble divided the spirals into normal and ________ categories.
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Galaxies that look like huge globular clusters are Hubble type ________.
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The spiral arms are blue from the presence of Population ________ stars in them.
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When mass is accreted into a black hole, what fraction of the total mass-energy can be radiated away?
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Why is the energy source for active nuclei like Seyferts thought to be compact?
A) The sources appear to be single stars in photos.
B) Their energy appears to be non-stellar synchrotron radiation.
C) The light can vary over short time intervals.
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In active galaxies, their central engines may be temporarily fed by
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Describe the cycle of life and death we observe in the spiral arms.
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Why aren't there young stars in the halo?
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What advantage do radio astronomers have over optical ones in mapping the entire Milky Way?
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How did Herschel try to map our Galaxy 200 years ago, and why did he fail?
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