1. Earth’s Moon How did our Moon form? and What’s been happening since?

2. What do you see?

3. Evidence a model must explain Moon is less dense than the rocky planets (Mercury, Venus, Earth, Mars) … it’s “lighter”. Less iron than Earth Moon is unusually big for a satellite Earth/Moon system has a lot of angular momentum (spin + orbital motion) Chemical composition similar to Earth’s mantle A tilted orbit relative to Earth’s path around the Sun How Did the Moon Form?

4. Movie Time! Movie of lunar evolution + tour from LRO Find the video here: http://svs.gsfc.nasa.gov/vis/a010000/a010900/a0 10930/evol_and_tour_ipod_lg.m4v

5. Hypothesis accepted by most planetary scientists since mid-1980s: Wham Moon! The GIANT Impact Hypothesis Explore Activity!

8. 4.5 billion years ago, our Moon forms (lunar rocks and meteorites) Lunar Geologic History

10. The Magma Ocean Explore Activities! Moon Mix!, Recipe for a Moon

12. Magma Ocean / Lunar Highland Rocks Anorthosite (a type of feldspar) – mostly CaAl 2 Si 2 O 8 4.44-4.51 Billion Years Old

13. Explore Activity! Splat!

14. Late Heavy Bombardment “Nice Model” 4.5 billion years ago3.9 billion years ago3.85 billion years ago Intense period of impacts on Moon (and everything else in Solar System) by comets and asteroids

15. Lunar Impact Basins (really big craters) Rim of Imbrium BasinOrientale Basin Big, frequent impacts until 3.8 billion years ago Impact events continue across our solar system today!

16. Lunar Impact Rocks Breccia

17. Lunar Geologic History Filling in the Basins SW Mare Imbrium Mare Imbrium Volcanism after impacts – most before 3 (to 1) billion years ago

18. Explore Activity! Moon Ooze

19. Lunar Basin Rocks Basalt 3.3 Billion Years Old

20. Volcanoes on the Moon There are a few actual volcanoes on the Moon Not nearly as many as Earth! No longer active

21. Dark, smooth Maria Basalt – fine grained dark igneous rock rich in iron and magnesium (heavy stuff that sank in magma ocean) Few hundred meters thick Rocks are 4.3 to 3.1 billion years old … flows as recently as 1 billion years ago Lunar Geologic History - Basins

22. A Brief Summary of Lunar Geologic History Moon Mix! Splat! Moon Ooze Impact Paintings and …

23. Tidal Evolution The Moon is far from the Earth! Why? The Moon is moving away from Earth by 3.8 centimeters each year! On average, the Moon is about 7 feet further away than when I was born  Moon was close to Earth billions of years ago.

24. All quiet except for impacts... Like this one in 2005 that made a 9 foot crater … Explore Activity!  0.15 seconds

26. Lunar Geologic History – Recent Activity Explore Activity! Trails of the Apollo 12 Astronauts