ASTRON C10 Lecture Notes - Lecture 7: Lunar Phase

• School: Berkeley
• Department: Astronomy
• Course: ASTRON C10
• Professor: Filippenko Alex

Document Summary

Moon phases are caused by a changing relative geometry between the sun, the earth, and the moon a. Half of the moon is always sunlit but we see phases because we don"t always see the side that"s lit up, we see the side that faces us i. It is the side that"s lit up in a full moon but none at all in a new moon b. c. Moon and earth aren"t exactly linear because that would make it an eclipse. The dark side of the moon isn"t totally dark a. b. Sunlight is reflected from earth then from the moon back to the earth. The sun"s diameter is 390 times bigger than moon"s, but its also 390 times farther away from the earth a. b.