1 / 49

STUDY of the EARTH’s Movements

STUDY of the EARTH’s Movements. 6 th Grade Science . What is mathematical shape is the Earth? . Sphere. What does it mean when an object is a sphere? . Sphere : a round, 3-dimensional object . Its surface is the same distance from its center at all points .

melba
Télécharger la présentation

STUDY of the EARTH’s Movements

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. STUDY of the EARTH’s Movements 6th Grade Science

  2. What is mathematical shape is the Earth?

  3. Sphere • What does it mean when an object is a sphere?

  4. Sphere: a round, 3-dimensional object • Its surface is the same distance from its center at all points

  5. What are other examples of spheresbesides the Earth?

  6. Spheres:

  7. There were many people who suspected that the Earth took the shape of a sphere.

  8. Aristotle –around 350 B.C. • Believed that the Earth was a perfect sphere and that all planets orbited around it

  9. Aristotle noticed that the Earth cast a curved shadowon the moon during an eclipse

  10. *Besides Aristotle, many other individuals suspected that the Earth was round. *How did they start suspecting this?

  11. Certain sailors also believed that the Earth was round. Why?

  12. Sailors noticed that in approaching ships, the tops of ships came across the horizon and appeared first

  13. Is the Earth a perfect sphere?

  14. No! • ItBULGESslightly at the equator • It is FLATTENEDat the poles • Not a PERFECT sphere

  15. Did you know that the movements of the Earth cause the day and night and the seasons?

  16. What would you guess causes day and night?

  17. Earth’s Rotation • Rotation: the action of spinning around an axis or center

  18. Earth’s Rotation • How does the Earth’s rotation cause day and night?

  19. As the Earth rotates, part of the Earth faces away from the Sun, and faces dark outer space. This is what causes day and night.

  20. How long does it take for the Earth to rotate once around its axis?

  21. 24 Hours!

  22. While it is day in the United States, it will be night in other parts of the world

  23. You can’t feel the Earth’s rotation, but standing on top of the Earth is like riding a giant spinning top

  24. As the Earth rotates, you can see the Sun come into view at daybreak.

  25. Earth continues to spin, making it seem as if the Sun moves across the sky until it sets at night

  26. During night, your area of the Earth has rotated so that it is on the opposite side of the Sun *We can’t see the Sun anymore, but the Sun is still lighting up the moon.

  27. What is the Earth’s axis?

  28. Earth’s axis: the imaginary vertical line around which Earth spins

  29. The Earth’s axis is tilted 23.5 degrees

  30. Because of this, the Earth is like a spinning top that is spinning slightly to the side.

  31. The tilt of the Earth’s axis is actually very important. What does the tilt of its axis cause?

  32. The tilt of Earth’s axis causes the seasons! It causes the seasons as it is revolvingaround the Sun

  33. REVOLUTION: to revolve is to move in a circular path around something else • Remember that the Earth revolves or orbits the Sun in the shape of an ellipse

  34. Earth’s axial tilt and ellipse-shaped revolution causes the seasons

  35. Find North America: When is it getting the most sunlight?

  36. The Sun shines more brightly on either the Northern and Southern hemisphere depending on the season

  37. Radiation from the Sun • Earth’s axial tilt causes the Sun’s radiation to strike the hemispheres at different angles • In Summer, the Northern Hemisphere is tilted toward the sun, so it is getting more direct sunlight

  38. During winter in North America, the Sun is still shining, but because of axial tilt, North America is facing away from it and not getting very much light.

  39. Daylight hours are longer for the hemisphere that is tilted toward the Sun because that hemisphere has more exposure to light for a longer period of time

  40. What is an Equinox?

  41. Equinox: occurs when the Sun is directly above the Earth’s equator

  42. Equinox: occurs 2 times per year • During an equinox, the number of daylight hours and nighttime hours is nearly equal all over the world • Northern Hemisphere: The Sun reaches the spring equinox on March 20-21, and the fall equinox occurs on September 22-23

  43. What is a Solstice?

  44. Solstice: either the longest day of the year or the shortest day of the year

  45. A Solstice is when the Sun is at its greatest distance from hitting the equator • Summer solstice in the Northern Hemisphere = June 21  longest day of the year • Winter solstice in the Northern Hemisphere = December 21  shortest day of the year

  46. Look at the Yellow Dots. Where are the Solstices?

  47. How long does one Revolution around the Sun take for planet Earth?

  48. 365 ¼ days • 4 Seasons

More Related