UNIT 1

UNIT 1 - The Sky

This is a sample exam - similar but NOT IDENTICAL to the midterm! Please note that questions with **** after them or in red are on material you are not yet responisble for.

True/False

Indicate whether the sentence or statement is true or false.

____ 1. The average distance from Earth to the sun is 1 AU.

____ 2. Precession of Earth's axis causes the date at which perihelion of Earth's orbit to occurs to slowly change.

____ 3. The constellations were created by the Greeks.

____ 4. Hipparchus devised the magnitude system in the late 1700s.

____ 5. During an annular eclipse of the sun, the corona of the sun is visible.

____ 6. A total solar eclipse will be visible from the same location on Earth one saros cycle later.

____ 7. The lunar tides on Earth are making the moon recede from Earth.

____ 8. Galileo used a telescope to observe the phases of Jupiter.

____ 9. Aristotle believed that objects falling to the ground fell at a constant speed.

____ 10. Copernicus was the first astronomer to suggest that planets orbited the sun in elliptical orbits..

Multiple Choice

Identify the letter of the choice that best completes the statement or answers the question.

11. How many centimeters are there in one kilometer?

a.	100
b.	1000
c.	10,000
d.	100,000
e.	1x10⁶

12. Scientific notation is used in science because

a.	it makes it easy to write big or small numbers.
b.	all astronomical distances are expressed in metric units.
c.	it makes conversions between units easy.
d.	all of the above
e.	none of the above

13. If the nearest star is 4.2 light-years away, then

a.	the star is 4.2 million AU away.
b.	the light we see left the star 4.2 years ago.
c.	the star must have formed 4.2 billion years ago.
d.	the star must be very young.
e.	the star must be very old.

14. The radius of the moon's orbit is about ________ times larger than the radius of Earth.

a.	0.6
b.	6
c.	60
d.	600
e.	6000

15. The Milky Way Galaxy****

a.	contains about 100 billion stars.
b.	is about 100 light-years in diameter.
c.	is the largest known object in the universe.
d.	all of the above
e.	a and c

16. 2.9 x 10⁷ is the same as

a.	2.9 thousand
b.	29 thousand
c.	290 thousand
d.	2.9 million
e.	29 million

17. 3.0 x 10⁵ times 1.5 x 10⁹ is equal to

a.	4.5 x 10⁴⁵
b.	4.5 x 10¹⁴
c.	2.0 x 10⁴
d.	2.0 x 10¹⁴
e.	2.0 x 10⁴⁵

18. If light takes 8 minutes to reach Earth from the sun and 5.3 hours to reach Pluto, what is the distance from the sun to Pluto?

a.	5.3 AU
b.	40 AU
c.	40 ly
d.	5.3 ly
e.	0.6 ly

19. An observer on Earth's equator would find

a.	Polaris directly overhead.
b.	Polaris 40° above the northern horizon.
c.	that the celestial equator coincides with the horizon.
d.	that the celestial equator passing directly overhead.
e.	that the ecliptic coincides with the horizon.

20. The ________ is the point on the celestial sphere directly above any observer.

a.	north celestial pole
b.	south celestial pole
c.	zenith
d.	celestial equator
e.	asterism

21. The apparent visual magnitude of a star is a measure of the star's

a.	size.
b.	intensity.
c.	distance.
d.	color.
e.	temperature.

22. Which star in the table below would appear the brightest to an observer on Earth?

Star	Apparent Visual
Name	Magnitude
d Dra	3.07
a Cet	2.53
r Per	3.98
Nim	8.07
a CMa	-1.46

a.	a Cet
b.	a CMa
c.	Nim
d.	r Per
e.	d Dra

23. The star Vega has an apparent visual magnitude of 0.03 and the star HR 4374 has an apparent visual magnitude of 4.87. It has been determined that both stars are at the same distance from Earth. What does this information tell us about the two stars?

a.	Vega must be closer to Earth than HR 4374.
b.	Vega must be farther from Earth than HR 4374.
c.	Vega must produce less energy than HR 4374.
d.	Vega must produce more energy than HR 4374.
e.	Vega will appear fainter to us than HR 4374.

24. An observer in the Northern Hemisphere takes a time exposure photograph of the night sky. If the illustration below depicts the photograph taken by the observer, which direction was the camera pointing?

a.	straight north
b.	straight east
c.	straight south
d.	straight west
e.	straight up, directly overhead

25. An observer in the Southern Hemisphere takes a time exposure photograph of the night sky. If the illustration below depicts the photograph taken by the observer, which direction was the camera pointing?

a.	straight north
b.	straight east
c.	straight south
d.	straight west
e.	straight up, directly overhead

26. An observer in the Southern Hemisphere takes a time exposure photograph of the night sky. If the illustration below depicts the photograph taken by the observer, which direction was the camera pointing?

a.	straight north
b.	straight east
c.	straight south
d.	straight west
e.	straight up, directly overhead

27. A solar or lunar eclipse will occur

a.	when the sun is near the line of nodes of the moon and the moon is new or full.
b.	any time the moon is new or full.
c.	when the sun is near the solstice and the moon is new or full.
d.	half way through an eclipse year.
e.	when the sun is near the equinox and the moon is new or full.

28. ___________ occur when the moon is new and when the moon is full.

a.	Neap tides
b.	Spring tides
c.	Total solar eclipses
d.	Annular eclipses
e.	A coppery red moon will

29. On average the moon's umbral shadow is

a.	to bright to produce a total solar eclipse.
b.	to faint to produce a total solar eclipse.
c.	to wide to produce a total solar eclipse.
d.	too long to produce a total solar eclipse.
e.	to short to produce a total solar eclipse.

30. The first quarter moon rises

a.	at about noon.
b.	at sunset.
c.	at sunrise.
d.	at about midnight.
e.	during the second week of each calendar month.

31. Which of the following is not visible during totality of a total solar eclipse?

a.	the corona of the sun.
b.	the chromosphere of the sun.
c.	prominences.
d.	the photosphere of the sun.
e.	all of the above

32. A marble has a diameter of 2 cm. At what distance would the marble have an angular diameter of 1 arc second****

a.	4.1 cm
b.	4.1 miles
c.	4.1 m
d.	4.1 ft
e.	4.1 km

33. A total solar eclipse occurred in Wolf Point, Montana on Feb. 26, 1979. When did (will) this eclipse again be visible in Montana?

a.	within 3 days of August 26, 1979
b.	within 3 days of March 29, 2033
c.	within 3 days of March 9. 1997
d.	within 3 days of March 13, 1979
e.	within 3 days of Jan. 1, 2000

34. A(n) _____________ is a single conjecture that can be tested.

a.	hypothesis
b.	paradigm
c.	natural law
d.	model
e.	theory

35. A(n) ____________ is a description of some natural phenomenon that can't be right or wrong. It is merely a convenient way to think about a natural phenomenon.

a.	hypothesis
b.	paradigm
c.	natural law
d.	model
e.	theory

36. Galileo's telescopic discoveries of mountains on the moon and spots on the sun were controversial because they suggested that the sun and moon

a.	were the same kind of object.
b.	were not perfect.
c.	were inhabited.
d.	orbited each other.
e.	did not orbit Earth.

37. Which of the following was not based on uniform circular motion?

a.	the Rudolphine Tables
b.	the Prutenic Tables
c.	the Alphonsine Tables
d.	the Almagest
e.	the Copernican system

38. A comet near the sun whose orbit is ____________ would never be near the sun again.

a.	elliptical
b.	circular
c.	hyperbolic
d.	apogee
e.	following an inverse square law

39. How much energy is released if 2 kg of matter is converted into pure energy?

a.	2 joules
b.	6 x 10⁸ joules
c.	1.2 x 10⁹ joules
d.	9 x 10¹⁶ joules
e.	1.8 x 10¹⁷ joules

40. What is the escape velocity from the moon for a lunar lander sitting on the moon's surface? The mass of the moon is 7.2 x 10²² kg, its radius is 1738 km.*****

a.	2.3 m/s
b.	23 m/s
c.	2.3 km/s
d.	23 km/s
e.	11 km/s

Completion

Complete each sentence or statement.

41. A(n) __________ is the largest known structure in the universe.

42. Our galaxy is part of a small cluster of approximately 2 dozen galaxies known as the _______________.

43. Star A has an apparent visual magnitude of 6.3 and star B has an apparent visual magnitude of 5.3. Star A is _________ times ________ than star B.

44. A(n) ___________ eclipse occurs when the moon is at its greatest distance from Earth and the moon is new.

45. The __________ month is the period of revolution of the moon to around Earth with respect to the stars.

46. The __________ of the sun is not visible during a total solar eclipse.

47. Uranus' orbital period is 84 years, how far is Uranus from the sun?

48. The ____________ Tables were based on a heliocentric model of the universe and used elliptical orbits for the planets.

49. The _________ is the path along which the planets and sun appear to move in the sky.

50. The _____________ is the critical speed needed to escape the gravitational pull of another body.

Essay

51. Describe the path that a star on the celestial equator follows from the time it rises until it sets for a person at a latitude of 60° N and a person at the equator.

52. Why can neither Venus nor Mercury remain visible throughout the night as the full moon does?

53. Why is the eclipse year shorter than 365.25 days.

unit1_test

Answer Section

TRUE/FALSE

1. T

2. T

3. F

4. F

5. F

6. F

7. T

8. F

9. T

10. F

MULTIPLE CHOICE

11. D

12. A

13. B

14. C

15. A

16. E

17. B

18. B

19. D

20. C

21. B

22. B

23. D

24. C

25. C

26. B

27. A

28. B

29. E

30. A

31. D

32. E

33. B

34. A

35. D

36. B

37. A

38. C

39. E

40. C

COMPLETION

41. filament

42. Local Group

43. 2.5; fainter

44. annular

45. sidereal

46. photosphere

47. 19 AU

48. Rudolphine

49. ecliptic

50. escape velocity

ESSAY

51. Answer not provided.

52. Answer not provided.

53. Answer not provided.