1. Planet Earth Part One: The Measurement of Time

2. The planet we live on is called Earth.

3. It is one of nine planets in our Solar System.

4. The word Solar means, “of or having to do with the sun.”

5. These nine planets orbit around the sun.

6. Each orbit equals one full trip around the sun.

7. Notice that the Earth’s orbit around the sun is not a perfect circle.

8. Earth’s orbit around the sun is called an “elliptical” orbit because it does form a perfect circle.

9. There are two points in Earth’s orbit of the sun that are significant.

10. They are the “Perihelion” and the “Aphelion”

11. “Perihelion” comes from two words, “ Peri” meaning around and “Helios” meaning sun.

12. The “Perihelion” is the point in Earth’s orbit when it comes closest to the sun.

13. Aphelion is made up from two words, “Apo” meaning from and “Helios” meaning sun.

14. The “Aphelion” is the point in the Earth’s orbit when it is furthest away from the sun.

15. When do you think we experience our summers, when we are at the Perihelion or the Aphelion?

16. You’re right! We experience summer when the Earth is at aphelion.

17. Even though the Earth is at the point farthest from the sun our hemisphere is tilted towards the sun and we receive more direct sunlight.

18. We experience our winter season when Earth is at it’s perihelion because our hemisphere is tilted away from the sun and we receive less direct sunlight.

19. We call the time it takes the Earth to complete an orbit around the sun a year.

20. There are twelve months in our year.

21. Four Seasons in our year: Summer, Fall, Winter, and Spring.

22. There are three hundred and sixty- five days in our year.

23. We have fifty-two weeks in our year 52

24. Each week has seven days

25. Each day has twenty-four hours.

26. Each hour has sixty minutes.

27. Each minute has sixty seconds.

28. Are there any questions?

29. 1.) What planet do we live on? a.) Mercury b.) Saturn c.) Earth d.) Pluto

30. 2.) How many planets are in our solar system? a.) Nine b.) Seven c.) Twelve d.) Five

31. 3.) What does the word “Solar” mean? a.) Soul b.) Son c.) Sold d.) Sun

32. 4.) The nine planets in our Solar System orbit around the? a.) Middle b.) Son c.) Sun d.) Center

33. 5.) Each orbit equals ? a.) One trip around the track. b.) One trip around the world. c.) One trip around the sun. d.) One trip to the principal’s office

34. 6.) Is Earth’s orbit around the sun a perfect circle? a.) Yes b.) No c.) I don’t know

35. 7.) The shape of Earth’s orbit is called…? a.) Circular b.) Eclipse c.) Square d.) Elliptical

36. 8.) The prefix “peri” means: a.) Sun b.) From c.) Around d.) At the side of

37. 9.) The prefix “apo” means: a.) Sun b.) From c.) Around d.) At the side of

38. 10.) The prefix “helios” means: a.) Sun b.) From c.) Around d.) At the side of

39. 11.) The point in the Earth’s orbit when it comes closest to the sun is called? a.) Bellerophon b.) Periodontist c.) Aphelion d.) Perihelion

40. 12.) The point in the Earth’s orbit when it is farthest from the sun is called? a.) Bellerophon b.) Periodontist c.) Aphelion d.) Perihelion

41. 13.) When do we experience our summers? a.) At Aphelion b.) At Perihelion

42. 14.) When do we experience our winters? a.) At Aphelion b.) At Perihelion

43. 15.) We experience summers at aphelion because…? a.) Our hemisphere is tilted away from the sun and not getting direct sunlight. b.) Our hemisphere is tilted toward the sun and getting more direct sunlight.

44. 16.) We experience winters at perihelion because…? a.) Our hemisphere is tilted away from the sun and not getting direct sunlight. b.) Our hemisphere is tilted toward the sun and getting more direct sunlight.

45. 17.) What do we call the time it takes the Earth to complete an orbit around the sun? a.) A Decade b.) A Year c.) A Century d.) A Season

46. 18.) How many months are in a year? a.) Four b.) Sixty c.) Twelve d.) Fifty-two

47. 19.) How seasons are there in a year? a.) Four b.) Sixty c.) Twelve d.) Fifty-two

48. 20.) What are the names of the four seasons? a.) _____________________c.) ______________________ b.) _____________________d.) ______________________

49. 21.) How many days are there in a year? a.) Three Hundred and sixty-five b.) Sixty c.) Twelve d.) Fifty-two

50. 22.) How many weeks are there in a year? a.) Four b.) Sixty c.) Twelve d.) Fifty-two

51. 23.) How many days are there in a week? a.) Four c.) Twelve b.) Sixtyd.) Seven

52. 24.) How many hours are in a day? a.) Four c.) Twenty-four b.) Sixtyd.) Seven

53. 25.) How many minutes are in an hour? a.) Four c.) Twenty-four b.) Sixtyd.) Seven

54. 26.) How many seconds are there in a minute? a.) Four c.) Twenty-four b.) Sixtyd.) Seven