3. The Earth and moon viewed from Mercury

4. The Earth viewed from Saturn

5. If you zoom in….

6. The Moon

7. What causes the phases of the moon?

9. What causes tides? to moon Earth

10. What causes tides? to moon Earth How many high tides are there each day? How many low tides are there each day?

11. How did the moon form?

12. Moon Basic Facts: The mass of the moon is about 1/100th that of Earth. The moon has little or no atmosphere. The moon has a low density compared to the Earth. The moon revolves around the Earth once every _______. The moon rotates on its axis once every ________. Therefore it is said to be in ________ rotation.

13. Moon Basic Facts: The mass of the moon is about 1/100th that of Earth. The moon has little or no atmosphere. The moon has a low density compared to the Earth. The moon revolves around the Earth once every month. The moon rotates on its axis once every month. Therefore it is said to be in synchronous rotation. (We only see ONE side of the moon from Earth!)

14. FYI (no need to memorize this): The Earth-moon system is evolving. The moon is moving outwards. The Earth is slowing down. Eventually, the moon will only see one face of the Earth. The timescale for this to occur on is...

15. FYI (no need to memorize this): The Earth-moon system is evolving. The moon is moving outwards. The Earth is slowing down. Eventually, the moon will only see one face of the Earth. The timescale for this to occur on is... 50 billion years

16. The moon and Earth, from Mars Express

17. If the Earth and moon were instead side by side…

18. Four pictures of Earth/moon from Deep Impact satellite

20. The Earth and moon have surprisingly similar compositions! http://www.psrd.hawaii.edu/Dec01/Oisotopes.html

21. How did the moon form?

22. Let’s watch some movies.

23. How did the moon form? Let’s watch some movies.

24. Moon: Basic Geology

26. Lunar Maria: Smoother, darker terrain caused by volcanic activity Does this look like volcanoes on Earth?

27. Lunar Maria: Smoother, darker terrain caused by volcanic activity Does this look like volcanoes on Earth?

28. Lunar lava comes out of fissures

29. Lunar Highlands: Rugged, bright terrain caused by collisions

30. Lunar cratering data has been used to understand the rates of impacts in the solar system. Only on the moon can we get absolute dates. (WHY?)

31. Should we go back? Are manned missions worthwhile? The Apollo program sent people and spacecraft to the moon from 1968-1972. No spacecraft have landed on the moon since.

32. The Moon: Take-away messages The phases of the moon are caused by the relative locations of the Earth, moon and sun. Tides are caused by the gravitational pull of the moon. The moon is in synchronous rotation- we only see one of its faces. The moon was formed by a giant collision, followed by the collection of impact debris. Geology on the moon is controlled by collisions and volcanism (but the volcanism is different from that on Earth) Cratering on the moon can be used to understand collision rates in the solar system.