The document summarizes key properties and motions of Earth and the Moon. It describes how Earth rotates on its axis, causing day and night, and revolves around the Sun, causing years. It also explains that the Moon rotates on its axis and revolves around Earth, and that the changing angles of sunlight cause its phases to cycle over 29.5 days.

1. Ch 23 Section I The Earth

2. Properties of the Earth people used to think that Earth was flat and at the centre of the universe

4. Earth is a round 3-dimensional sphere

5. Proof the Earth is round Aristotle saw a curved shadow on moon during an eclipse See top of ship sails first Sailors noticed different stars in the night sky

6. Axis – imaginary vertical line around which earth spins

7. Rotation – the spinning of Earth around its axis that causes day and night Takes 24 hrs. or 1 day

8. Earth has a magnetic field with north and south poles

9. Caused by: 1- the movement of material in core 2- Earth’s rotation Protects us from harmful solar radiation by trapping charged particles

10. Magnetic north vs. geographic north

11. Revolution – Earth’s yearly orbit around the sun

12. Revolution vs. rotation Revolution – trip around Sun Earth orbits around the Sun Earth is a satellite of the Sun Rotation – spinning on axis Cause of night/day

13. Earth’s orbit is an ellipse or elongated, closed curve

14. The Sun is not centered in the ellipse Perihelion : closest point (winter) Aphelion : furthest point (summer)

15. Distance from Sun Earth closest Jan. 3: 147 million kilometers Earth furthest July 4: 152 million kilometers Small difference 5 million kilometers so… Earth is exposed to almost the same amount of Sun year round

16. Earth’s tilt causes the seasons

17. Tilt causes radiation to strike at different angles The more direct the angles receive more radiation

18. Seasons on Earth The height of the sun above the horizon varies with the season.

19. Solstice the day when the sun reaches its greatest distance north or south of the equator Summer solstice: June 21 or 22 in northern hemisphere Sun directly over Tropic of Cancer Winter solstice: December 21 or 22 in northern hemisphere Sun directly over Tropic of Capricorn

20. Equinox the day when the sun is directly over Earth’s equator Daytime and nighttime hours are equal all over the world

21. Vernal (Spring) equinox: March 20 or 21 in northern hemisphere Autumnal (Fall) equinox: September 22 or 23 in northern hemisphere

23. Geocentric – everything revolves around earth

24. Heliocentric – everything revolves around the sun

25. Moon

26. Motions of the moon rotates on its axis takes 27.3 days for one revolution Always the same side facing earth b/c moon rotates and revolves at the same speed

27. The moon seems to shine because it reflects sunlight

28. Games/activities http://www.sciencenetlinks.com/interactives/moon/moon_challenge/moon_challenge.html http:// www.engagingscience.org/games/onlinegames/games.html http://aspire.cosmic-ray.org/labs/moon/lunar_phases_main.html

29. Moon Phases – the different forms the Moon takes in its appearance from Earth

30. New Moon – when the moon is between earth and the sun and cannot be seen

31. Waxing phases more of the illuminated half of the moon that can be seen each night after the new moon

32. First visible thin slice of the moon is a waxing crescent

33. First quarter phase – half the lit side of the moon is visible Waxing gibbous – more than one quarter is visible

34. All of the Moon’s lit side is visible during a full moon

35. Waning phases – less of the illuminated half of the Moon is visible after the full moon.

36. Waning gibbous – starts after a full moon where more than half of the lit side is still visible. Third quarter - half the Moon’s lit side is visible

37. The last visible slice before a new moon is called the waning crescent

38. Phases of the Moon

39. What time period did we get from studying the moon? Completes its moon cycle in 29.5 days Completes revolution in 27.3 days

40. The moon’s orbit is tilted about 5 degrees relative to Earth’s orbit around the sun.

41. visuals http://www.ioncmaste.ca/homepage/resources/web_resources/CSA_Astro9/files/multimedia/unit3/phases_moon/phases_moon.html

42. Eclipses – when the Earth or the moon casts a shadow on the other

43. Solar Eclipse the moon moves directly between the Earth and the Sun, shadowing part of the Earth

44. Penumbra – experiences a partial eclipse Umbra – experiences a total eclipse

45. A total solar eclipse is visible only on a small area of Earth The corona is the silvery part

48. Lunar Eclipse – when Earth’s shadow falls on the moon What color does the moon turn during as eclipse?

49. Does not occur every month because the moon’s orbit is tilted to earth’s orbit.

50. NASA - Total Lunar Eclipse: February 20, 2008

51. The moon is 3,476 km in diameter, a little less than the distance across the contiguous United States.

52. Moon’s gravity is 1/6 of Earth’s gravity because it is less massive

53. The Moon’s surface has many depressions, or craters. formed from meteorites, asteroids, and comets

54. What could destroy the footprint?

55. Cracks in the Moon’s crust caused lava to fill large craters, forming maria, or dark, flat areas Mountainous area called highlands

56. http:// stardate.org/pdfs/teachers/ObservingTheMoon.pdf Shows marias

57. Regolith is the broken rock material on the moon’s surface. Moon rocks are similar to ours and have tiny crystals of pure iron.

58. Data from moonquakes suggest that under the Moon’s crust might lie a solid mantle, then a partly molten mantle and a solid, iron rich, core.

59. Impact Theory of Moon Origin the Moon formed 4.6 billion years ago from Earth material thrown off when a large object collided with Earth

60. Impact Basins or craters, are depressions left by objects striking the Moon (or anything else!!!!!)

61. Arizona Crater 20,000-50,000 years ago Asteroid 80 feet in diameter 1.2 kilometers in diameter

62. Chicxulub, Mexico Now covered by the Yucatan Penninsula Asteroid 6 mi (10 km) Crater diameter 110 miles (180 km) 65 million years ago Cretaceous period

63. Albedo reflectance

64. Albedo of 0

65. Albedo of 1

66. Clementine January 25, 1994 Objective to test lightweight sensors Task was to map the surface of the moon Cost 80 million Bet. 2/26 – 4/22 1.8 million images Carried cameras – infrared to ultraviolet

67. Clementine Northside Farside Nearside Southside

68. Clementine 3 billion metric tons at poles

69. Lunar Prospector Desk sized 1998 Confirmed impact theory

70. Graphic Organizer rotates revolves causing causing Earth

71. Graphic Organizer rotates revolves causing causing Earth On its axis Night and day Around the Sun years