AST 2002 Lecture Notes - Lecture 5: Apparent Retrograde Motion, Lunar Phase, The Moons
Document Summary
Why do we see phases of the moon: lunar phases are a consequence of the moon"s 29. 5-day orbit around earth. Phases of the moon: 29. 5-day cycle: half of the moon is illuminated by the sun and half is dark, we see a changing combination of the bright and dark faces as the moon orbits earth, waxing. Gets fuller and rises later each day: waning. Answer: noon: first quarter moon is between new and full moons. What causes eclipses: the earth and moon cast shadows, when either passes through the other"s shadow, we have an eclipse. What causes lunar eclipses: lunar eclipse: when the moon passes through the shadow cone of earth, lunar eclipses can occur only at full moon. We see the light of all the sunsets on earth. Ast 2002: solar eclipses happen when the moon blocks the sun"s shadow from earth, solar eclipses can occur only at new moon, solar eclipses can be partial, total, or annular.