1. Wednesday October 24, 2012 (Earth’s Moon)

2. The Launch Pad Wednesday, 10/24/12 Name the three leading hypotheses for lunar formation and denote the one that is now the most widely accepted. On what basis is this one the most accepted? The Moon was formed at the same time as Earth, and from the same accretion disk material. The Moon is a captured asteroid or dwarf planet. A Mars-sized impactor collided with Earth and dug out material from which the Moon formed. The collision theory is the most widely accepted based upon the composition of the Apollo Moon rocks.

3. The Launch Pad Wednesday, 10/24/12 Name the three phases of lunar evolution in the correct chronological order. highlands maria rayed craters

4. Announcements Happy Fall

5. Assignment Currently Open Summative or Formative? Date IssuedDate Due Date Into GradeSpeed Final Day Quiz 6S110/5 10/26 Quiz 7S210/12 10/26 WS – Dwarf Planets F310/1810/2210/24 Quiz 8S310/19 11/2 WS – Trans- Neptunian Regions of the Solar System F410/2210/26 WS – Our Solar System F510/2310/2510/26

6. Recent Events in Science Expedition 33/34 Launches to the ISS http://www.nasa.gov/mission_pages/station /living/index.html Read All About It! Three new crew members are on their way to join their Expedition 33 crewmates onboard the International Space Station. They launched aboard the Soyuz TMA-06M spacecraft on Tuesday from the Baikonur Cosmodrome, Kazakhstan. Flight Engineers Kevin Ford, Oleg Novitskiy and Evgeny Tarelkin will orbit the Earth for two days before docking to the Poisk module at 8:35 a.m. Thursday. The new trio will join Commander Suni Williams and Flight Engineers Aki Hoshide and Yuri Malenchenko who’ve been residing at the orbital laboratory since July 17. http://www.nasa.gov/multimedia/videogallery/index.html ?media_id=154404551 Watch the Video

7. Earth’s Moon Our Moon has a diameter of 2,160 miles, which is unusually large compared to its parent planet, the Earth. The density of the Moon is about 3.3 times that of water, which is comparable to Earth’s crustal rocks. Perhaps the Moon has a small iron core, but not nearly as extensive as that of Earth's core.

8. Since the Moon has only 1/6 of the mass of the Earth, it has only 1/6 of Earth’s gravitational attraction. The Moon has no atmosphere, and is no longer tectonically active. The Moon’s surface has been bombarded by micrometeorites from space, which gradually made the landscape smooth. Earth’s Moon

9. There are two basic types of terrain on the lunar surface: The highlands are the bright, densely cratered regions which make up most of the Moon’s surface. Highlands make up all of the far side of the Moon, and are much older than the maria regions. The maria (singular, mare - Latin for “sea”) are the darker regions on the near-side of the Moon. They are fairly smooth lowlands, and originated from asteroid impacts causing magma to flood the impact craters. Earth’s Moon

10. Major Topographic Features on the Lunar Surface Figure 22.6

11. The Moon’s craters are the most obvious features on the lunar surface. Most of these craters were produced by impactors, which splashed out lunar material referred to as “ejecta.” Occasionally craters will have prominent “rays.” Rays are usually associated with younger craters. Earth’s Moon

12. Crater Tycho crater) Rays

13. Lunar regolith (what we call soil here on Earth) is gray, unconsolidated debris that covers all lunar terrains. Regolith is composed of Igneous rocks: breccia and glass beads. On the surface there is a thin layer of fine lunar dust, which Neil Armstrong referred to as being like a “powder.” The “soil-like” layer is produced by eons of meteoric bombardment. Earth’s Moon

14. Moon “phases” are caused by the changing angle from which we here on Earth view the sunlit half of the Moon. Highlands

15. Moon Phases Highlands

16. The Fate of the Moon

17. Imagine yourself riding a bicycle on a track built around a Merry- go-Round. You are riding in the same direction that it is turning. If you have a lasso and rope one of the horses, you would gain speed and the Merry-Go-Round would lose some. In this analogy, you and your bike represent the Moon, the Merry-Go-Round is the rotating Earth, and your lasso is gravity. In orbital mechanics, a gain in speed results in a higher orbit.

18. The Fate of the Moon The Moon is gradually receding from the Earth, at a rate of about 4 cm per year. This is caused by a transfer of Earth's rotational momentum to the Moon's orbital momentum as tidal friction slows the Earth's rotation. That increasing distance means a longer orbital period, or month, as well.

19. The Fate of the Moon The slowing rotation of the Earth results in a longer day as well as a longer month. Once the length of a day equals the length of a month, the tidal friction mechanism would cease. For example, once your speed on the track matches the speed of the horses, you can't gain any more speed with your lasso trick. That's been projected to happen once the day and month both equal about 47 (current) days, billions of years in the future. If the Earth and Moon still exist, the distance will have increased to about 135% of its current value. http://www.speed- light.info/speed_of_light_12000.htm http://www.youtube.co m/watch?v=ZpUFLNd WycM Watch the video. Check out this website!