Ch2 Patterns in the Sky—Motions of Earth Verified Test Bank

Chapter 2: Patterns in the Sky—Motions of Earth and the Moon

LEARNING OBJECTIVES

2.1 Earth Spins on Its Axis

2.1a Identify the locations of the north celestial pole, south celestial pole, celestial equator, zenith, meridian, and horizon on the celestial sphere.

2.1b Estimate the altitude of an object in the sky.

2.1c Explain why the celestial sphere is only a model of the sky and not reality.

2.1d Explain the apparent path of a star on the sky from the time it rises until it sets.

2.1e Explain how the star’s apparent position and motion in the sky change with one’s location on Earth.

2.2 Revolution Around the Sun Leads to Changes During the Year

2.2a Identify the ecliptic, the solstices, and the equinoxes on the celestial sphere.

2.2b Relate Earth’s position around the Sun with the zodiacal constellations observed in the nighttime.

2.2c Explain why Earth’s axial tilt with respect to its orbital plane causes seasons.

2.2d Explain why the tropical year leads to leap years in the calendar.

2.2e Explain how the height of the Sun and the length of a day vary with season and observer latitude.

2.3 The Moon’s Appearance Changes As It Orbits Earth

2.3a Identify the phases of the Moon.

2.3b Predict the phases of the Moon.

2.3c Explain the causes of Moon phases.

2.3d Understand the Moon’s synchronous rotation.

2.4 Shadows Cause Eclipses

2.4a Explain the Sun-Moon-Earth geometries needed to produce solar and lunar eclipses.

Working It Out 2.1

Working It Out 2.1a Relate distance, speed, and time to solve for one variable given the other two.

Chapter 2: Patterns in the Sky—Motions of Earth and the Moon

MULTIPLE CHOICE

1. The direction directly overhead of an observer defines his or her

a. meridian. c. circumpolar plane.

b. celestial pole. d. zenith.

2. What is the altitude of an object in the sky that is seen directly above an observer?

a. 0 c. 90

b. 45 d. 180

3. No matter where you are on Earth, stars appear to rotate about a point called the

a. zenith. c. meridian.

b. celestial pole. d. equinox.

4. All stars denoted on the celestial sphere are

a. equidistant from Earth.

b. actually planetary bodies of the solar system.

c. at varying distances from Earth.

d. not in the Milky Way galaxy.

5. If the star Polaris has an altitude of 55then we know that

a. our longitude is 55. c. our longitude is 35.

b. our latitude is 55. d. our latitude is 35

6. At a latitude of 50, how far above the horizon is the north celestial pole?

a. 0 c. 50

b. 40 d. 90

7. The local meridian is defined as a great circle on the sky on which lie the

a. celestial equator and vernal equinox.

b. north and south celestial poles.

c. zenith and the north and south celestial poles.

d. zenith and east and west directions.

8. If the north celestial pole is located at your zenith, what is your latitude?

a. 0 c. 60

b. 30 d. 90

9. If the north celestial pole is located on your horizon, what is your latitude?

a. 0 c. 60

b. 30 d. 90

10. The north celestial pole and the celestial equator are always separated by what angle?

a. 0 c. 60

b. 30 d. 90

11. The apparent path of the Sun across the celestial sphere during a year is called the

a. prime meridian. c. circumpolar plane.

b. ecliptic line. d. celestial equator.

12. The ecliptic plane is defined by the apparent motion of __________ in the sky.

a. the Moon c. Polaris

b. the Sun d. the stars

13. If you go out at exactly 9 p.m. each evening over the course of 1 month, the position of a given star will move westward by tens of degrees. What causes this motion?

a. Earth’s rotation on its axis

b. the revolution of Earth around the Sun

c. the revolution of the Moon around Earth

d. the revolution of the Sun around Earth

14. The shortest day of the year for a person living in the Northern Hemisphere is the

a. summer solstice. c. winter solstice.

b. vernal equinox. d. autumnal equinox.

15. On which day of the year does the Sun reach its northern-most point in the sky?

a. vernal equinox c. autumnal equinox

b. summer solstice d. winter solstice

16. When the Northern Hemisphere experiences summer, the Southern Hemisphere experiences

a. spring. c. fall.

b. summer. d. winter.

17. Earth’s rotational axis precesses in space and completes one revolution every

a. 200 years. c. 26,000 years.

b. 1,800 years. d. 51,000 years.

18. Leap years occur because

a. Earth’s orbital period around the Sun is decreasing.

b. Earth’s tropical year is 365.24 days.

c. the Gregorian calendar contains only 11 months.

d. Earth speeds up in its orbit when it comes closest to the Sun.

19. How many days are in a tropical year?

a. 365 c. 365.256

b. 365.242 d. 366

20. About every 4 years we add a calendar day to which month?

a. February c. April

b. March d. May

21. The Earth’s axial tilt is 23.5. If the Earth’s axial tilt was 15, which would be true?

a. The seasons would remain the same. c. Winters would last longer.

b. Summers would be warmer. d. Winters would be warmer.

22. Assume you are observing the night sky from a typical city in the United States at a latitude of 40. Use the following figure to determine which constellation of the zodiac would be nearest the meridian at midnight in March.

a. Scorpius c. Aquarius

b. Gemini d. Leo

23. We experience seasons primarily because

a. Earth’s equator is tilted relative to the plane of the Earth’s orbit around the Sun.

b. Earth is closer to the Sun in summer and farther from the Sun in the winter.

c. the length of the day is longer in the summer and shorter in the winter.

d. Earth moves with a slower speed in its orbit during summer and a faster speed during winter.

24. Assume you are observing the night sky from a typical city in the United States at a latitude of 40. Use the following figure to determine which month it is if the zodiac constellation Taurus is on your meridian at midnight.

a. July c. January

b. November d. May

25. The amount of the Earth’s surface receiving sunlight during the day is

a. the same in the Northern and Southern Hemispheres during June.

b. less in the Southern Hemisphere than in the Northern Hemisphere during December.

c. more in the Northern Hemisphere than in the Southern Hemisphere during December.

d. less in the Northern Hemisphere than in the Southern Hemisphere during December.

26. If you went out tonight and looked at the sky at midnight, at what time would you have to observe 6 months from now to find the stars in approximately the same position in the sky? Assume that you could see the stars at any time, day or night.

a. 6 a.m. c. 6 p.m.

b. noon d. midnight

27. The shortest day of the year for a person living in the Southern Hemisphere is the

a. summer solstice (June 21). c. winter solstice (December 21).

b. vernal equinox (March 20). d. autumnal equinox (September 22).

28. For a person who lives at a latitude of 40, when is the Sun directly overhead at noon?

a. only on the summer solstice

b. only on the vernal and autumnal equinoxes

c. never

d. always

29. Assume you are observing the night sky from a typical city in the United States at a latitude of 40. Use the following figure to determine which constellation of the zodiac would be nearest the meridian at 6 p.m. in September.

a. Sagittarius c. Aquarius

b. Gemini d. Leo

30. Assume you are observing the night sky from a typical city in the United States at a latitude of 40. Use the following figure to determine which constellation of the zodiac would be rising at 10 p.m. in May.

a. Pisces c. Gemini

b. Virgo d. Capricornus

31. In consecutive non–leap years, the exact time at which the autumnal or vernal equinoxes occur is

a. later than the times they occurred in the previous year.

b. earlier than the times they occurred in the previous year.

c. exactly the same times they occurred in the previous year.

d. randomly earlier or later than the times they occurred in the previous year.

32. If you travel 40 miles from home to school in 30 minutes, what is your average velocity?

a. 20 mph c. 80 mph

b. 40 mph d. 1.3 mph

33. The Moon undergoes synchronous rotation, which means the

a. rotational period of the Moon equals the orbital period of the Moon around Earth.

b. rotational period of the Moon equals the rotational period of Earth.

c. rotational period of the Moon equals the orbital period of Earth around the Sun.

d. Moon does not rotate as it orbits Earth.

34. Which of the following is true about the Moon?

a. The same side of the moon always faces the Earth.

b. The rotational period of the Moon is 24 hours.

c. The Moon rotates faster than it orbits the Earth.

d. The Moon does not rotate as it orbits Earth.

35. In regard to the phase of the Moon, the term waxing means

a. less than half-illuminated. c. becoming smaller.

b. more than half-illuminated. d. increasing in brightness.

36. If tonight the Moon is in the waxing gibbous phase, in 3 days the Moon will most likely be in the

a. new phase. c. third quarter phase.

b. full phase. d. first quarter phase.

37. If there is a full Moon out tonight, approximately how long from now will it be in the third quarter phase?

a. 3 to 4 days c. 2 weeks

b. 1 week d. 1 month

38. Which of the following is true?

a. Everyone on Earth observes the same phase of the Moon on a given night.

b. The phases of the Moon cycle with a period of approximately 2 weeks.

c. The Moon can only be observed during the night.

d. The Moon rises about 1 hour earlier each night.

39. We observe different phases of the Moon because

a. the Moon passes through different portions of the Earth’s shadow during its orbit.

b. some parts of the Moon reflect and other parts absorb sunlight.

c. the orbital position of the Moon determines which portion and how much of the facing lunar surface is illuminated by sunlight.

d. the Moon emits light in some places and only reflects light in other places.

40. The gibbous is in the “waning” state between the

a. third quarter and new Moon phases. c. first and second quarter phases.

b. new Moon and first quarter phases. d. full Moon and third quarter phases.

41. At what time does a third quarter Moon rise? (Hint: A third quarter Moon occurs approximately 3 weeks after a new Moon.)

a. midnight c. 6 a.m.

b. noon d. 6 p.m.

42. At what time does the waxing gibbous phase rise?

a. 3 p.m. c. 3 a.m.

b. 9 a.m. d. 9 p.m.

43. If a person on Earth currently views the Moon in a waxing crescent phase, in what phase would the Earth appear to a person on the Moon?

a. waxing crescent c. waning gibbous

b. waxing gibbous d. waning crescent

44. What is demonstrated in the following figure?

a. phases of the moon c. synchronous rotation

b. eclipse seasons d. that the Moon doesn’t rotate

45. During which lunar phase do solar eclipses occur?

a. new c. full

b. first quarter d. third quarter

46. During which lunar phase do lunar eclipses occur?

a. new c. full

b. first quarter d. third quarter

47. A partial lunar eclipse occurs when

a. the Sun appears to go behind the Moon.

b. the Moon passes through part of Earth’s umbra.

c. the Moon shadows part of the Sun.

d. Earth passes through part of the Moon’s shadow.

48. Solar and lunar eclipses are rare because the Moon’s orbital plane is tipped by

a. 5.2relative to the plane defined by Earth’s equator.

b. 5.2 relative to Earth’s orbital plane.

c. 23.5 relative to the plane defined by Earth’s equator.

d. 23.5 relative to Earth’s orbital plane.

49. Approximately how often do lunar eclipses occur?

a. about twice per year c. twice per month

b. once per month d. once every 11 years

50. What is the maximum amount of time the Sun can be totally eclipsed by the Moon on a given location?

a. 4 minutes c. 8.3 minutes

b. 7.5 minutes d. 1 hour 40 minutes

1. The following figure is a time exposure of the sky, showing the motion of the stars through the night. What is the name for the stars that never rise or set below the horizon?

2. The center of the Milky Way lies approximately 30° south of the celestial equator. From what latitudes on Earth is it impossible to view the center of our galaxy?

3. On what place(s) on Earth can you stand and have the great circle of the celestial equator be at the same height relative to your horizon for all 360 of its circumference?

4. For the following figure, label the north and south celestial poles, the celestial equator, and the ecliptic.

5. How is the observed height of Polaris above the horizon related to an observer’s latitude? (Hint: Consider three cases of observers located at the equator, the North Pole, and latitude 45.)

6. How is the observed altitude of the celestial equator related to an observer’s latitude of 40 if the observer is facing due south?

7. What would be the effect on the seasons if the tilt of Earth’s axis were 10 rather than 23.5?

8. Earth experiences seasons because of the tilt of its axis. What are the two consequences of this tilt that contribute to the seasons?

1. Variation in the length of daylight.

2. Variation in the directness of the Sun’s rays.

DIF: Medium REF: 2.2

OBJ: 2.2c Explain why Earth’s axial tilt with respect to its orbital plane causes seasons.

MSC: Applying

9. Explain the differences between the length of day during equinoxes and solstices. Does it matter if the observer is in the Northern or Southern Hemisphere?

10. The following figure shows four locations of the Sun on the ecliptic. Label each appropriately with the labels autumnal equinox, vernal equinox, summer solstice, and winter solstice.

11. For an observer in Seattle, Washington, which is located at latitude 47, what is the minimum height above the southern horizon that the Sun will have throughout the year, and approximately when will this occur?

12. On which great celestial circle(s) on the celestial sphere would you find the position of the autumnal equinox?

13. Earth’s orbit has an average radius of approximately 1.5 10⁸ km. What is the average speed of the Earth as a result of the revolution of Earth around the Sun in kilometers per second (km/s) if there are 3.16 10⁷ seconds per year?

14. How does gibbous differ from crescent?

15. The following figure shows the different phases of the Moon. Label each phase of the Moon shown.

16. The following figure shows the different phases of the Moon. Label each phase of the Moon. Approximately what time would the full Moon rise above your horizon? The third quarter Moon? The new Moon? The first quarter Moon?

17. The following figure shows the different phases of the Moon. Label each phase of the Moon. What time would the full Moon be on your meridian? The new Moon?

18. Explain why we always see the same side of the Moon from Earth.

19. If the Moon was full 3 days ago, what phase will it be tonight and when will it rise and set?

20. How does the appearance of the first quarter Moon phase differ from the third quarter Moon phase? Why?

21. The following figure shows a lunar eclipse. What type of lunar eclipse is it?

22. Why can a solar eclipse only occur during a new Moon?