Moon

1. Moon Ch-25

2. Exploration of the moon • Moon is only 386000 km away • Need to aim at where it will be • Off by seconds will mean it misses the moon and goes into orbit around the sun • Slow down to obtain lunar orbit by using retro rockets

3. First object in space Sputnik First to the moon luna 1 Did a flyby then into orbit around the sun luna 2 Crashed into the moon first object to reach the moon luna 3 Orbited and returned pictures first pictures of the far side of the moon How did we do itSoviets

4. Pioneer series Pioneers 1,2,3 Unsuccessful Pioneer 4 Flyby of moon 1961 kennedy Speech “land an astronaut on the moon and return him safely to Earth” We had not even put a man in space yet Soviets had orbited Yuri Gagarin 1 orbit 108 minutes Soviets sent up Gherman Titov 17 orbits 25 hours USA

5. Two Prong Approach • #1 Build something to land on the moon • #2 Build something to get a human into space

6. Landing on the Moon • Ranger probes • purpose send back pictures of the moon then crash into it • Ranger 4 did it • first American object on the moon • Ranger 7,8 &9 finished the job • Surveyor probes • purpose land on the moon and determine conditions

7. Mercury missions Mercury 3 Alan Shepard Flight was suborbital but proved we could launch and bring them back Mercury 6 John Glenn 3 orbits 5 hours Gemini missions 1965-1966 (2 people) Proved we could stay up long enough to get to the moon Proved we could dock with another spacecraft Putting Man into Space

8. Going to the moon • Apollo missions (1969) • Neil Armstrong & Edwin Alden jr. first to walk on the moon • went six times • Spacecraft was 110 meters tall and weighed 3 million kilograms • only 6000 kilograms return

9. Three Theories as to the Origin of the Moon • Formed at the same time and from same material • Capture theory • Was formed elsewhere and captured by Earth’s gravity • Spinning Theory • Earth’s was spinning so fast that some of it was thrown into space • Collision theory • 4.5 billion yrs ago an object the size of a planet collided with Earth knocking a piece off • hit off center

10. Development of the Moon • Continued to grow from meteoroid impacts (4.5 –4 bill yrs ago) • Impacts would melt the surface leaving huge magma fields • Allowed the lighter material to float to the top • Impact would form craters & Mountains

11. Impacts slowed (4 – 3 bill yrs ago) • Earth and moon had swept through most of the object in their orbital paths • Lava flows up through some of the cracks in the craters to fill the basins • Darker in color • Interior cooled to inactive status • Still being bombarded by micrometeoroids • Little atmosphere does not allow them to burn up

12. Moon Properties • Rotation rate equal revolution rate • same side is always facing Earth • Diameter = 3476 km • ¼ Earth’s • Mass = 1/18 Earth’s • Density = 3.3 gr/cm3 • Earth = 5.5 gr/cm3 • Gravity =1/6 Earth

13. Lunar Landscape • Maria • Thought to be seas (Dark in color) • basaltic magma filled basins • youngest lunar rocks at 3.1 – 3.8 bill yrs • Mascons • A Maria with higher gravity readings • denser material below • Rilles • Trenches that formed from flowing lava • hard crust forms then roof caves in

14. Highlands • Light colored • Mountains and craters (some up to 5 km) • thrust up by impacts • older 4 – 4.5 bill yrs old • Craters • Pits created by meteoroids (2100 km across) • Rims are large cliffs (some 1000’s of meters)

15. Rays • Streaks that radiate out from a crater • Length depends on • size of object • larger = larger • speed of object • faster = larger • angle of object • shallower = larger

16. Regolith • lunar soil • no water • dust and rock particles • grayish brown in color

17. Motion of the Moon • Rises in the east sets in the west • Apparent motion due to earth’s rotation • Rises & sets 50 minutes later each day • ex) rise today at 3:00 tomorrow at 3:50 • Revolution = 27 1/3 days • Lunar month is 29.5 days • difference in time is because of earth’s movement in it’s orbit

18. Orbit of the Moon • Off by 5 degrees • Causes eclipses at different times • Elliptical • Apogee • farthest away (moon appears small) • Perigee • Closest (Moon appears large)

19. Phases of the Moon • Half of the moon is always lit • Terms • waxing – lit part getting larger • Waning – lit part getting smaller

20. Eclipses • When an object is in the shadow of another • Types of shadows • Umbra - darkest part • Penumbra - lightest part • Types of eclipses • lunar eclipse • the moon is blocked out by the shadow from the earth • must be at full moon

21. Lunar Eclipse SUN EARTH MOON

22. Solar eclipse • the sun is blocked out by the moon • must be at new moon • Two types • Partial - in the penumbra • Total - in the umbra

23. Solar Eclipse Partial eclipse (Penumbra) EARTH Moon Total eclipse (Umbra) Partial eclipse (Penumbra)

24. Effects of the Moon • Tides • A bulge of water pulled around the planet • Rise and fall with the moon • 50 min later each day • Every spot has four tides a day • 2 high and 2 low • Each lasts 6 hours and 12.5 minutes

25. Types of Tides • Spring tide • high high tides and low low tides • caused by the moon and sun lining up to create a larger than average pull • new and full moon phases • Neap Tide • Low high tides and high low tides • Caused by the sun and moon pulling at right angles • Quarter phases

26. Spring Tides Moon Earth Sun Sun Moon Earth

27. Neap Tides Moon Earth Sun