1. Ch. 28 Sec. 2 The Moon

2. Reaching for the Moon  Soviet Union launched Sputnik I in 1957 –First step into understanding our space  1961, Soviet astronaut Yuri A. Gagarin became first human in space  U.S. Project Mercury launched first American, Alan B. Shepard, in space: 1961  1969, Apollo Program landed Armstrong and Aldrin on the moon: Apollo 11

3. Lunar Properties  Our moon, one of the largest known moons  Only moon for the inner planets  Only moon that is solid and rocky, others are ice  Moon is 27 % of Earth’s radius

4. Lunar Surface  Lunar surface is quite dark –The albedo is only.07% reflective –Albedo is the amount of sunlight reflected –B/c of no atmosphere:  127 o C in sunlight  -173 o C in darkness

5. Lunar Surface  No erosion except that of other impacts  Highlands –Light in color –Mountainous: heavily covered with craters –Impact craters: Ejecta and Rays

6. Lunar Surface  Mare or Maria –Dark smooth plains –Rilles: valley like structures

7. History of Moon  Moon is aged from 3.8 -4.6 bil. Yrs. Old  Moon heavily bombarded in first 800 mil yrs –Resulted in breaking & heating of rocks –Formed loose ground layer known as regolith

8. Moon tectonics  Infer from seismometer data that moon has layers  B/c of known volcano activity & magnetic field, little to no tectonic act. On moon

9. Moon formation Theories  Capture Theory –Beginning of solar system, an object ventured to close to earth –Got caught in the gravity field –Problem: earth and moon of similar elements  If came from somewhere else, would be different elements

10. Moon formation Theories  Simultaneous Formation Theory –Earth and moon formed in general area and the same time –Moon did not have to be slowed down –Problem  Different accounts of Iron on moon than Earth

11. Moon formation Theories  Impact Theory –Gigantic collision on earth that ejected into air –Materials merged together to form the moon –Iron deficient crust and all water would have evaporated on collision

12. Impact Theory