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1 | | Describe why, in order to be considered living, an object must contain DNA or another substance that has the same capabilities. |
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2 | | What properties of water are crucial to life on Earth? Discuss the advantages and disadvantages of ammonia and methyl alcohol versus water as liquids on which life might be based. |
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3 | | The oceans of the early Earth probably contained high concentrations of organic molecules. Where did those molecules come from? |
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4 | | How does the nebular theory differ from the catastrophic theories of the origin of the solar system with respect to its predictions about the rarity of other planetary systems? |
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5 | | Why have attempts to find planets beyond the solar system concentrated on giant planets like Jupiter rather than terrestrial planets? |
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6 | | What kind of observations were used to discover planets orbiting nearby stars like the Sun? |
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7 | | Discuss the ways in which the recently discovered planetary systems are similar to and different from the solar system. |
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8 | | Why does the habitable zone of a star change its location as time passes? |
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9 | | What is the relationship between the length of time that life endures on a typical planet and the number of inhabited planets in the galaxy? |
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10 | | Why does it follow that if our attempts at interstellar communication are likely to succeed, we are very likely to be the junior partners in the conversation? |
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11 | | Suppose someone suggested that the "logical" frequencies at which to search for interstellar signals are precisely 1 or 10 GHz. Present an argument that there is nothing special or logical about those frequencies. |
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12 | | If we discover life on other planets, how is human civilization likely to be affected? (There is no "correct" answer to this question, but it is an interesting subject for speculation.) |
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