1. 27.3 – Sun-Earth-Moon System https://www.youtube.com/watch?v=onj dfrhmBrI

2. *Essential Vocabulary Ecliptic Summer Solstice Winter Solstice Autumnal Equinox Vernal Equinox Synchronous Rotation Neap Tide Spring Tide Solar Eclipse Perigee Apogee Lunar Eclipse Centrifugal Force Precession Nutation

3. Daily Motions Earth’s rotation causes us to see daily rising and setting of the Sun, Moon, and stars – Rises in the East, sets in the West – We observe changes in their location due to the Earth rotating

4. Day Length Solar day – time from one noon to the next noon – Length of a day is approximately 4 minutes longer than it takes the Earth to make one rotation on its axis http://www.uni-heidelberg.de/university/museums/pendel.jpg Foucault pendulum

5. Annual Motions Earth orbits the sun in a slightly elliptical orbit – Plane of Earth’s orbit is called ecliptic plane – This movement causes us to see different constellations in the sky during different times of year

6. Earth’s tilt The Earth’s axis is tilted 23.5° – Axis remains fixed in space – Cycle of seasons is due to this tilt When Northern hemisphere points towards the sun = Summer When Southern hemisphere points towards the sun = Summer

7. Solstices The Sun is at its farthest distance either north or south of the equator ( Below or Above )

8. Summer Solstice around June 21 st In Northern Hemisphere, number of daylight hours reaches its maximum Sun is in the sky continuously with the region of the Arctic Circle

9. Winter Solstice Around December 21 st In Northern Hemisphere, number of daylight hours is at its minimum Sun does not appear in the region within the Arctic Circle

10. Equinox Equal nights Earth’s axis is perpendicular to the Sun’s rays and at noon the Sun is directly overhead at the equator Vernal – March 20, 2013 Autumn – Sept. 23, 2013

12. Phases of the Moon Phases of the Moon The moon does not produce its own light – reflects light of the Sun The shape of the lighted portion of the moon, as seen from Earth, is known as its phases.

13. http://www.afreshhorizon.co.uk/images/moon_phases.jpg Draw Phases!

14. Phases of the Moon New Moon = moon is between Earth & Sun – So we do not see light reflected off of its surface Waxing = lighted area is increasing due to position between Earth & Sun Crescent = “sliver” of moon is visible 1 st Quarter = ½ lit up Gibbous = almost Full

15. Crescent and gibbous moons

16. Phases of the Moon Full Moon Waning = decreasing amount of moon reflecting light due to position Gibbous 3 rd Quarter = opposite half lit up after full moon Crescent New Moon

17. First quarter v’s last quarter moons

18. Earthshine Only during early crescent phases, “dark” part shines dimly, due to reflected light off the Earth

19. OPEN NOTE VOCAB QUIZ 1.__________ linking several telescopes together to act as one. 2.__________ formed when objects from space crashed into the Moon’s surface. 3.__________ loose, ground-up rock 4.__________ the amount of sunlight that the Moon’s surface reflects 5.__________ Nasa technologies passed on to commercial industries

20. Quiz Continued 6.__________ The plane in which Earth orbits the Sun. 7.__________ The Sun is directly overhead at the Tropic of Capricorn 8.__________ The Sun is directly overhead at the Tropic of Cancer 9.__________ The farthest point in the Moon’s orbit to Earth 10._________ Occurs when the Moon passes through Earth’s shadow

21. Synchronous Rotation Moon rotates with a period equal to its orbit period Spins only once each time it goes around the Earth

22. Lunar Motions Lunar Month = complete cycle of phases from one New Moon to the next – Rotation = 29.5 days Moon rises and sets 50 minutes later each day

23. Tides Moon’s gravity pulls on Earth and creates bulges of ocean water As Earth rotates, bulges remain aligned with moon http://www.absoluteaxarquia.com/nightsky/images/tides.gif

24. Spring Tides Spring tides occur during the full moon and the new moon When the moon is full or new, the gravitational pull of the moon and sun are combined. At these times, the high tides are very high and the low tides are very low

25. Neap Tides Neap tides occur during quarter moons During the moon's quarter phases the sun and moon work at right angles, causing the bulges to cancel each other. The result is a smaller difference between high and low tides and is known as a neap tide. Neap tides are especially weak tides

26. Solar Eclipses Solar Eclipses Moon passes directly between Sun and Earth Blocks sunlight Total eclipse only visible in small portion of Earth – Partial eclipse is seen in larger portion For more information see pg. 793

27. A series of photos of a solar eclipse!

28. A total solar eclipse!

29. A partial solar eclipse!

30. This solar eclipse shows flares (storms) on the edges of the sun!

31. Annular eclipses Eclipse with ring of the Sun visible – Moon in apogee Due to the elliptical orbit of Moon causes it to be closer to Earth during parts of its orbit – Perigee – closest point of Moon’s orbit to Earth – Moon appears larger – Apogee – farthest point Moon appears smaller

32. An annular solar eclipse!

33. This is the difference between a perigee and apogee moon!

34. Lunar Eclipses Occurs with Moon passes through Earth’s shadow – Earth is between Moon and Sun Moon faintly visible because Earth’s atmosphere is filtering sun light Lasts about 2 hours

35. Lunar eclipse – time elapsed pictures

36. Umbra and Penumbra Umbra-The completely dark portion of the shadow cast by the earth, moon, or other body during an eclipse Penumbra-A partial shadow, as in an eclipse, between regions of complete shadow and complete illumination

37. http://www.timeanddate.com/e clipse/list.html

38. Time Zones Because of sun’s apparent motion, sun appears highest over different locations at different times World divided into 24 standard time zones – In each zone, noon is when sun is highest over the center of that zone

39. Precession of the Equinoxes What is Nutation? It is a rocking, swaying, or nodding motion in the axis of rotation of a largely axially symmetric object (EARTH) “wobbling” What is Precession? -is a change in the orientation of the rotational axis of a rotating body “orbiting motion” http://www.youtube.com/watch?v=0qHjtp4cdCA

41. Earth average distance of 92,955,820 miles (149,597,890 km) from the sun Third planet from the sun and one of the most unique (WE HAVE LIFE ON EARTH) 4.65 billion years old Largest of the terrestrial planets (bigger than Mercury, Venus, and Mars)

42. What is the shape of Earth? Its shape is an oblate spheroid or ellipsoid, instead of a true sphere -This means that instead of being of equal circumference in all areas, the poles are squished, resulting in a bulge at the equator, and thus a larger circumference and diameter there

43. Time Zones Earth rotates 15 degrees every hour Each time zone is one hour earlier than the zone to its east International Date Line – point where earth changes from one day to the next

45. Daylight Savings Time Change your clocks November 3rd at 2 AM – Fall back an hour – Spring forward an hour (March 10 th ) By changing your clocks, you gain an extra hour of daylight

46. Are calendars tied in with the moon? Day: time it takes Earth to make a full rotation Month: Time it takes the moon to go through one cycle

47. Are calendars tied in with the moon? Year: Time needed for the earth to make one orbit (revolution) around the sun (365.25 days – makes us add a day every four years – leap year) The days of the week were named after the Sun, moon, and the five known planets.