Unformatted text preview: is greatest when it is furthest from the Sun (C) is constant throughout its orbit (D) is greatest when it is midway between its aphelion and perihelion (E)is greatest when it is undergoing retrograde motion 10. Lunar eclipses can occur (A) once every month (B) when the Moon passes the celestial equator (C) when the Moon is in between the Earth and the Sun (D) only when the Sun is at the vernal or autumnal equinox (E) when the Moon crosses the ecliptic 11. Ocean tides are primarily caused by (A) the centrifugal force caused by the Earth’s rotation (B) the fact that the Moon’s orbit about Earth is elliptical, not circular (C) the fact that the Earth’s orbit about the Sun is elliptical, not circular (D) The precession of the Earth’s rotational axis. (E) the difference in strength of the gravitational force between the Moon and opposing sides of the Earth 12. A parsec is (A) the amount of time it takes for light to travel from the Sun to the Earth (B) the distance from which one astronomical unit subtends an angle of one arcsecond (C) the amount of time it takes for the Moon to make one full orbit with respect to...
View Full Document
- Spring '08
- Astronomy, 23 Hours, 31 years, 105 km, 104 km, 63 years