Stars & Galaxies Chapter 28 – Flashcards
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Which of the following appears most favored by natural selection?
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inteligence
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Organic molecules are:
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carbon-based
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How long between the evolution of single versus multicellular organisms?
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2.5 billion years
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The famed meteorite with carbonate rocks and possible microfossils came from:
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Mars
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Which of the following does NOT reveal information about conditions on the early Earth?
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evidence gleaned from other planets in the early stages of their evolution
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What unusual discovery was made about the Murchison Meteorite?
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It contains amino acids
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Why is the hypothesis that life on Earth came from outer space considered plausible?
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because many meteorites contain complex organic molecules
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The first step in cosmic evolution is:
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particulate evolution
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During which step in cosmic evolution did diverse life forms begin to arise?
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biological evolution
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The unusual nature of viruses (behaving as living organisms while within them, but becoming inert while isolated) has caused scientists to consider the possibility that:
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the definition of life may be more complex than a simple check list
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An experiment was done where a "primordial soup" of water, methane, carbon dioxide and ammonia was electrified. Following this, the material was found to contain many of the amino acids found in all living things on Earth. The purpose of this experiment was to:
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determine wether amino acids could have formed naturally on Earth
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What was detected on Halley's Comet and observed on Hale-Bopp that simply imply the possibility of life on Earth originating in space?
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organic material
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Of all the chemical elements, the one most crucial to the complexity of life is:
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carbon
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In addition to Mars, which jovian moon shows some promise of life, with a surface not that different from the Arctic Ocean?
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Europa
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What do Viking, Pathfinder, and the two Mars Rovers have in common?
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They all were designed to investigate Mars' potential for life
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Which of these does Mars NOT have to help its case of past or present life?
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a protective ozone layer
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According to our definition, we have been a technological civilization for about:
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100 years
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If we are optimistic in our assumptions about the development of life and intelligence, then the number of technological civilizations in the galaxy should equal the:
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average lifetime of a civilization
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Which type of star would have the largest habitable zone?
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O5V
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The Drake equation calculates N. What is N?
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the number of technical civilizations in our galaxy presently
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How is a technical civilization defined?
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a civilization that can communicate over interstellar distances
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Considering both longevity and luminosity, which of these stars would be the most likely candidate for seeking extraterrestrial intelligence?
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61 Cygni, a K2 main sequence star
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According to the parameters derived for the Drake Equation, where should astronomers look for life in the Milky Way?
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around F, G, or M stars that are in single star systems located in the galactic habitable zone with a multiple planet system with jovian outer planets and at least one terrestrial planet within the star's habitable zone
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Most SETI searches are done at
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radio wavelenghts
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To date, our serious searches for terrestrial life have been done almost entirely:
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with radio telescopes
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As a radio source, the period of "pulsar Earth" is:
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23 hours, 56 minutes
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Which of these radio waves would fall in the "water hole"?
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19 cm wavelenght
