天文学英文版PPT资料.ppt

Epicycles are used in a geocentric model to explain the eastward motion of Mars. westward motion of Mars. phases of Venus. appearance of Venus in the early morning or late evening sky. phases of the moon. Epicycles are used in a geocentric model to explain the eastward motion of Mars. westward motion of Mars. phases of Venus. appearance of Venus in the early morning or late evening sky. phases of the moon. When Jupiter is at opposition (see diagram), it is overhead (i.e., on the meridian) at 6:00 A.M. 12:00 noon. 6:00 P.M. midnight. never at night. When Jupiter is at opposition (see diagram), it is overhead (i.e., on the meridian) at 6:00 A.M. 12:00 noon. 6:00 P.M. midnight. never at night. A planet in an elliptical orbit around the Sun moves most rapidly when it is at aphelion. at perihelion. halfway between perihelion and aphelion. closer to aphelion than perihelion. None of the above; it has a constant speed. A planet in an elliptical orbit around the Sun moves most rapidly when it is at aphelion. at perihelion. halfway between perihelion and aphelion. closer to aphelion than perihelion. None of the above; it has a constant speed. Kepler’s three laws were initially derived from fundamental physics laws. were initially found from observation and are empirical rules that describe how the planets move. were handed down from the ancient Greeks. were discovered by Kepler in ancient Babylonian texts. are now known to be grossly incorrect. Kepler’s three laws were initially derived from fundamental physics laws. were initially found from observation and are empirical rules that describe how the planets move. were handed down from the ancient Greeks. were discovered by Kepler in ancient Babylonian texts. are now known to be grossly incorrect. Two planets are in circular orbits around similar stars. Each is the same distance from its parent star. One planet is Jupiter’s size, whereas the other is Earth’s size. Which of the following