Stars On a clear night how many stars can you see 2000 3000 Why is that Light Pollution Ancient cultures grouped the stars by location and named them after heroes animals monsters ID: 1044981
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2. Astronomy Motions of the Stars, the Earth and the Moon.
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4. StarsOn a clear night, how many stars can you see?
5. 2,000 – 3,000
6. Why is that?
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8. Light Pollution
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14. Ancient cultures grouped the stars by location and named them after heroes, animals, monsters….
15. Constellations
16. Earliest known groups:Leo and Taurus -5,000 years ago.There are over 400 named groups of stars.
17. International Astronomical UnionIn 1928 reduced number to 88 official constellations
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19. Asterism:Informally defined groupsExample:Big Dipper – (Ursa Major)Little Dipper – (Ursa Minor)
20. Stars in constellations are often very far from one another but we see them in the same direction in the sky.Big Dipper
21. Celestial Sphere: A huge imaginary sphere around the Earth to which the stars appear to be attached.But in reality the celestial sphere is stationary and the earth is rotating counterclockwiseALL MOTION 15°/HR
22. Stars appear to be moving from east to west.Rise in the east and set in the west.
23. Northern part of the sky around PolarisCounter clockwise rotationMoving west to east
24. The complete circular path can be seen for stars in the northern part of the sky around PolarisCircumpolar constellations never set.
25. STARS APPEAR TO ROTATE AROUND POLARIS
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27. The Earth’s Motions
28. Rotation-the spinning of the Earth on its axis(axis – an imaginary line running through the poles)
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30. The Earth rotates once every 24 hours
31. The Earth rotates once every 23 hours and 56 minutes
32. PrecessionWobbleCompared to a spinning topPeriod (time to complete one circle) is 26,000 years
33. Revolution-The movement of the Earth in its orbit around the Sun
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35. The Earth revolves once every 365 days
36. The Earth revolves once every 365.25 days
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38. Average distance:93,000,000 miles1 Astronomical Unit1 A. U.
39. Reasons for the Seasons
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41. Measure to nearest tenth of a cm
42. Bold lines are separated by10 million miles20 mil40 mil60 mil80 mil
43. 1,075,000,000Distance = (miles)Length (cm)Conversion Factor
44. Date Length (cm) Distance (miles)* Make a data table on back of your graph paper.
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46. Ellipse Vocabulary:Ellipse – a circle based on two center pointsEccentricity – Deviation from an established pattern – circle
47. Focus – center pointMajor Axis – long axis of ellipse, containing the 2 fociMinor Axis – shorter axis of ellipse, perpendicular to major axis
48. Circle – a closed plane curve, where every point is equidistant from a fixed point within the curve
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50. The Moon
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53. Once Believed to influence personal behavior
54. Moonstruck
55. Lunacy
56. Werewolves
57. Distance:240,000 Miles- closest sky object
58. Visits:6 Apollo Moon missions 1969-1972843 pounds of moon rock
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61. Moon MotionRises – Sets – Due to -EastWestEarth’s Motion
62. Rotates once every 27 1/3 daysRevolves once every 27 1/3 days
63. Synchronous Rotation- The earth observes the same side of the moon at ALL TIMES
64. Moon Phases
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70. What we observe from earth
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