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Questions and Answers
The Sun and Moon, however, used no ______ (both have almost uniform motion about the sky).
epicycles
For Mercury and Venus, Ptolemy needed to lock the centers of their ______ to the direction of the Sun.
epicycles
The stars appeared to be fixed on a celestial sphere rotating once each day about an axis through the geographic poles of ______.
Earth
The greatest angular displacements for Mercury and Venus set their orbital sizes relative to Earth’s orbital size by forming right angle ________.
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Earth seems to be unmoving from the perspective of an earthbound observer; it feels solid, stable and ______.
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The observed time for a planet to move from opposition to quadrature yields a right-angle ________.
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Planetary orbital periods correlate with the distance from the ________.
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Galileo Galilei was one of the first people to point the telescope at the sky and made it ________.
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The eccentricity of a circle is ____, while a line would have an eccentricity of 1.
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The closest approach of a planet to the Sun is known as the ____, a distance equal to a (1 - e).
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Kepler's Second Law of Planetary Motion states that a line connecting the planet with the Sun sweeps over an area at a ____ rate.
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In consequence, when a planet moves closer to the Sun, its orbital velocity must ____, and vice versa.
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