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• Midnight• Noon13. The true orbital period of a planet around the Sun, compared to thebackground stars, is called its• synodic period.• sidereal period.• rotation period.14. A friend from New York City tells you that she saw Venus high in thesky at midnight on Christmas Day in 2004. Why do you know that she iswrong?• Venus is always too faint to be seen in the winter from the northern hemisphere.• The orbit of Venus is close to the ecliptic, and therefore it cannot be seen from the latitude of New York City.• Venus is an inferior planet and always sets before midnight because it remains close to the Sun in our sky.15. Suppose that on some particular day the straight line from the Sunto the Earth continues on to pass through Mars and ultimately throughsome particular star in the sky. (Drawing a diagram might be helpful.)One synodic period later, Mars will again be lined up• with the star and the Sun, but not with the Earth.• with the Earth and the star, but not with the Sun.• with the Earth and the Sun, but not with the star.16. The synodic period for a planet is different from its siderealperiod because• the Earth (and hence the observer) moves.• the planet's speed varies as it moves around the Sun in its orbit.• the planet's orbital distance from the Sun is different from that of the Earth from the Sun.17. Tycho Brahe's major contribution to the development of modernastronomy was• the detailed and precise measurement of the positions of stars and planets in our sky.• a detailed and successful description of how a star can explode.• the first telescope observations of the variation of apparent shapes and sizes of planets, particularly Venus andMercury.18. The shape of the Earth's orbit around the Sun is• elliptical, with the Sun at the center of the ellipse.