1. Lunar Motion & Eclipses

2. Lunar Phases Caused by Moon’s changing position around the Earth See dif. portions of the lit half of Moon Waxing phases: from new moon to full moon, right side of moon becomes illuminated Waning phases: from full to new moon, left side is illuminated & see less of the moon.

3. Phases of the Moon

4. Synchronous Rotation Same side of the Moon faces Earth always Because Moon rotates at the same speed it revolves

5. General Motion Statistics Lunar month: time it takes to go through cycle of phases (29.5 days)Lunar month 27.3 days for moons orbit Rises and sets 50 min. later ea. Day Remember the same side of the moon always faces Earth ?Why?

6. Lunar Month vs. Orbital Period

7. General Motion Statistics Moon’s orbit is tilted ~5 o (reason for infrequent eclipses) Perigee: Moon closest to Earth Apogee: Moon farthest from Earth

8. Moon’s Orbit

9. Tides Bulge of ocean water on both sides of Earth caused by Moon’s gravitational pull Spring tide: Moon & Sun cause higher than normal high tides, and lower low (full & new Moon) Neap tides: Moon at 90 o angle to Sun, difference btwn high and low are not as drastic (Qtr. Phases)

10. Tides and Phases

11. Eclipses Light is blocked from an object, which causes a shadow on it Solar eclipse: Moon’s shadow cast on Earth (can’t see Sun)Solar eclipse Lunar eclipse: Earth’s shadow cast on the Moon (still see moon, but appears reddish in sky)Lunar eclipse

12. Eclipses cont’d Partial eclipse when observer isn’t under the concentrated shadow 2 regions of Moon’s shadow Umbra: Moon’s concentrated shadow ~100mi wide (total eclipse) Penumbra: Moon’s diffuse shadow (partial eclipse)

13. Solar Eclipse

15. Lunar Eclipse