Moons

1. Moons

2. Moons

3. Moons • Many moons in our Solar System • They have craters, volcanoes, possibly underground oceans A radar mapping image made by the Cassini spacecraft of a flyover area on Saturn's giant moon Titan showing an ice volcano

4. Satellites • Natural (not man made) or artificial bodies that revolve around larger bodies such as planets are called satellites • Mercury and Venus have no natural satellites • All other planets have moons (satellites)

5. Our Moon • What are the light colored areas? • What are the dark colored areas?

6. Answers • Highlands that have been impacted by craters (in the past) • Lowlands that were impacted by craters… then filled in with lava from beneath the moons surface (no longer has lava)

7. Mapping the moon • Neil Armstrong, BuzzAldrin, and Michael Collins landed on the Sea of Tranquility on July 20, 1969

8. What is it like on the moon? • No air • No oceans (water) • No clouds • No life • Less gravity • 5/6 (83%) less • If you weigh 100 pounds on Earth  you would weigh 16.6 pounds on the moon • Lots of dust

12. Is the moon far away from Earth? • Yes… and no • It’s the closest object to us in the solar system • Avg. distance from Earth is 380,000 km (236,121 miles) • It takes about 3days in a rocket ship • It would take 3 weeks if you were traveling at 500 mph

13. How big is the moon?

14. How heavy is the moon?

15. Luna: The Moon of the Earth • Solar system is 4.6billion years old • Based this data from lunar rocks brought back from Apollo mission

16. Surface of the Moon • Impact craters on the moon tell the age of the moon • If the surface is young, there hasn't been time for many craters to form • Different parts of the surface of the Moon exhibit different amounts of cratering and therefore are of different ages

17. How did the moon form? • Giant Impact Theory

18. Lunar Origins • Formation of the moon happened in three steps • 1stImpact – large body collided with earth, blasted part of Earth’s mantle in space • 2ndEjection – sent mantle debris from Earth and from impacting body (including its iron core) • 3rdFormation – debris orbited around Earth and began to join together

19. Moon Formation • http://vimeo.com/2015273

20. Phases of the Moon • http://www.sumanasinc.com/webcontent/animations/content/moonphase.html • Waxing – sunlit fraction is getting larger • Waning – sunlit fraction is getting smaller • Moon always gets same amount of sun( same as Earth) • You always see same side of the moon

21. Phases of the Moon • Appearance of the moon from its changing position relative to Earth and the sun • As moon revolves around Earth, amount of sunlight on the side of the moon that faces Earth changes • Called Phases

22. Waxing and Waning • Waxing – sunlit fraction is getting larger • Waning – sunlit fraction is getting smaller • Crescent – croissant shaped or fingernail clipping • Gibbous – bulging outward

23. Phases

24. Tides • Caused by the moons gravity • Pulls on the water toward the moon • High tide • Opposite side also high tide • Moon’s gravity also pulls on the center of the Earth

25. High tide vs Low tide

26. Spring Tides • You always have twohigh tides and twolow tides • Spring Tides have nothing to do with the season. • Spring tides happens when moon is full or new – when sun and moon are aligned • Spring tides = very high and very low tides

27. Spring Tide • When the sun, moon, and Earth are in alignment during a new or full moon • extra-high high tides, and very low, low tides

28. Spring Tide • During each lunar month, two sets of spring and two sets of neap tides occur

29. Neap Tides • Happens when sun and moon are NOT aligned • Happens during quarter phases • Gravitational forces cancel each other out • This canceling of forces causes the tides to not be dramatically low or high

30. Neap Tide • sun and moon are at right angles to each other • the solar tide partially cancels out the lunar tide • produces moderate tides known as neap tides

31. Neap Tide • Caused by the moons gravity • Pulls on the water toward the moon • High tide • Opposite side also high tide • Moon’s gravity also pulls on the center of the Earth

32. Eclipses – two types • Solar • Lunar

33. How does a lunar eclipse happen? • Moon passes directly behind Earth… • …In its shadow • Penumbra- • Lighter part of the shadow • Umbra- • Darkest part of Earth’s shadow

34. Penumbra to Umbra • Total eclipse- • Moon passes completely into the umbra • Partial eclipse- • Moon misses all or part of the umbra Penumbra Umbra

35. Why does the moon appear red? • The moon appears red because light bends around earth. • Red wavelengths of light are the longest… only ones to reach the moon

36. How does a solar eclipse happen? • Solar eclipse- • Moon passes directly between the sun and Earth • Casts a shadow onto Earth’s surface

37. Partial solar eclipse • The moon covers only part of the sun • Can still see the sun

38. Isn’t the moon to small to block the sun? • Total solar eclipse • The moon is 1/400 the size of the sun… • …but it is so much closer to us that it appears large… • …large enough to block the sun

39. Tilted Orbit of the Moon • Why don’t you see solar and lunar eclipses every month? • Moon’s orbit around Earth is tilted by about 5 degrees. • Just enough to place moon out of Earth’s shadow for most full moons and Earth out of the moon’s shadow for most new moons. Smile once in a while Lay off the Steroids. Get some Sun