Earth’s Motions

Review Sheet

1.  Where is the sun in relation to the earth’s orbit? (Kepler’s 1st law)

2.  What name is given to the shape of the earth’s nearly circular orbit?

3.  What is aphelion? When is the earth at this point in its orbit?

4.  What is perihelion? When is the earth at this point in its orbit?

5.  What causes night?

6.  During which time period do days in the Northern Hemisphere become longer?

7.  During which time period do days in the Northern Hemisphere become shorter?

8.  Which direction does the earth rotate?

9.  Which direction does the earth revolve?

10.  What two forces keep celestial bodies in orbit?

11.  Describe the differences between direct and indirect rays of light.

On the blanks, write whether the observation is a result of Earth’s REVOLUTION or ROTATION.

12.  The sun rises in the morning. ______

13.  The constellations visible in the southern sky in February are different than those

visible in August. ______

14.  The constellation Auriga is right overhead at 8:00 pm. ______

15.  The Coriolis effect causes weather patterns to appear to deflect to the right in the U.S. ______

16.  Pittsburgh’s average low temperature was 28o in March, but 68o in July. ______

17.  It is dark in Pittsburgh, but the sun is still above the horizon in Sacramento, CA. ______

18.  Foucault’s pendulum appeared to change the direction of its path over the course of the day. ______

19.  On the diagram below, label the following:

Autumnal Equinox Winter Solstice (northern hemisphere) Sept. 22nd Vernal Equinox Summer Solstice (northern hemisphere) June 20th March 20th Dec. 21st

20.  What date has the longest daylight hours of the year in the Northern Hemisphere?

21.  What date has the shortest?

22.  When are the daylight hours and nighttime hours equal?

23. How long does it take the earth to make one trip around the sun?

24.  At any given time, how much of the earth is facing the sun? Why?

25.  How long does it take the earth to make one complete rotation?

26.  Day and night depend on the earth’s ______.

27.  The sun seems to move across the sky from _____ to _____.

28.  What factors (MORE THAN ONE) affect the seasonal variations we experience on Earth?

29.  What is precession?

30.  Think back to the object that your mission team chose for further NASA study. How could NASA scientists predict what kind of seasonal variations an observer on that planet/moon/dwarf planet would experience?