Name: __________________________  Date: _____________

1.	The declination of a star in our sky is defined as	
A)	the angle between the position of the center of the Galaxy and the star, measured along the galactic plane.	
B)	the angle between the celestial equator and the star, measured along a great circle passing through both celestial poles.	
C)	the angle between the Sun and the star, measured along the ecliptic plane.	
D)	the angle between the great circle passing through the star and both celestial poles and the equivalent great circle through the vernal equinox, measured along the celestial equator.	

2.	The angle between your zenith and your horizon is	
A)	57.3°.	
B)	90°.	
C)	45°.	
D)	180°.	

3.	The Sun rises due east in the sky when viewed	
A)	from any site along the Earth's equator at midsummer and midwinter.	
B)	from any site on the equator on every day of the year.	
C)	from any site on the Earth on the first day of summer and the first day of winter.	
D)	from any site on the Earth, but ONLY on the first day of spring and the first day of fall.	

4.	Which of the following lines or points is always directly over your head, no matter where on the Earth you go?	
A)	The celestial equator	
B)	The ecliptic	
C)	The zenith	
D)	90° north declination	

5.	Two celestial coordinates, which together describe a star's position precisely in our sky, are	
A)	longitude and latitude.	
B)	sidereal time and latitude.	
C)	right ascension and declination.	
D)	right ascension and sidereal time.	

6.	The nightly motion of objects across our sky from horizon to horizon is caused by	
A)	the motion of the solar system around the Galaxy.	
B)	the revolution of the Earth around the Sun.	
C)	the rotation of the whole celestial sphere of stars around the fixed Earth.	
D)	the rotation of the Earth on its axis.	

7.	As an observer moves toward increasing latitude, the number of circumpolar stars	
A)	increases if the location of the observer is east of the Greenwich Meridian but decreases if the location is west of this meridian.	
B)	remains approximately constant.	
C)	decreases.	
D)	increases.	

8.	An observer on the equator will be able to see what fraction of the overall sky over a period of one year?	
A)	50%	
B)	100%	
C)	A variable amount, depending upon the person's longitude	
D)	Somewhat less than 100% except in a leap year	

9.	Where would you have to be in order to see the north celestial pole directly over your head (i.e., in your zenith)?	
A)	On the equator	
B)	At the North Pole of the Earth	
C)	At a position about 1° away from the South Pole, to account for precession	
D)	At the South Pole of the Earth	

10.	Leap years, containing an extra day, are necessary because	
A)	the Earth's speed of revolution along its elliptical orbit varies throughout the year.	
B)	365 days is not exactly divisible by four.	
C)	the rotation rate of the Earth varies, leading to days of different length during the year.	
D)	the length of a year is not an exact number of days.	

11.	The ecliptic can be defined as	
A)	the extension of the Earth's equator onto the sky.	
B)	the plane that is perpendicular to the Earth's spin axis.	
C)	the path traced out by the Moon in our sky in one month against the background stars.	
D)	the path traced out by the Sun in our sky over one year against the background stars.	

12.	The ecliptic crosses the celestial equator	
A)	at two points, known as equinoxes.	
B)	on the meridian.	
C)	at two points, known as solstices.	
D)	at one point only, known as the vernal equinox.	

13.	What will the right ascension of the Sun be on June 21 of this year?	
A)	6 hours 0 minutes	
B)	0 hours 0 minutes	
C)	12 hours 0 minutes	
D)	18 hours 0 minutes	

14.	If the Earth's spin axis were to be perpendicular to the plane of its orbit (the ecliptic), seasonal variations on the Earth would	
A)	be nonexistent.	
B)	remain the same as they are at present.	
C)	have the same severity but each season would last twice as long.	
D)	be much more severe.	

15.	From the Earth's North Pole, how long will the Sun remain above the horizon once it first appears at the beginning of spring?	
A)	Less than 1 hour	
B)	Just a few minutes	
C)	About 6 months	
D)	Exactly 12 hours	

16.	When the Sun is at one of the equinoxes,	
A)	the day is longer than the night in one hemisphere of the Earth and shorter in the other hemisphere.	
B)	day and night are of equal length only for people on the equator.	
C)	people on the equator have perpetual daylight.	
D)	day and night are of equal length everywhere on the Earth.	

17.	At the summer solstice in the northern hemisphere, the Sun	
A)	reaches its highest angle in the sky for the whole year.	
B)	is at its lowest angle above the southern horizon at midday, for the whole year.	
C)	is on the celestial equator.	
D)	is nearest to the Earth.	

18.	Precession is	
A)	the slow coning motion of the spin axis of the Earth, similar to that of a spinning top.	
B)	the gradual reversal of the Earth's magnetic field.	
C)	the motion of the Earth along its orbital path during a year.	
D)	the daily spinning motion of the Earth, producing the apparent motion of the Sun and the stars.	

19.	Why do we see different phases of the Moon?	
A)	Because the illuminated half of the Moon becomes more or less visible from Earth as the Moon orbits the Earth	
B)	Because the Moon's distance from the Earth changes as it moves in its elliptical orbit, thereby changing its apparent brightness	
C)	Because the Earth's shadow gradually moves over the Moon's surface as the Moon orbits the Earth	
D)	Because the Moon's rotation brings more or less of the illuminated hemisphere into view from the Earth	

20.	At approximately what time will the new Moon rise?	
A)	Sunset	
B)	Close to sunrise	
C)	Midday	
D)	Midnight	

21.	When will the first-quarter Moon rise, approximately?	
A)	6 A.M.	
B)	Midnight	
C)	6 P.M.	
D)	Noon	

22.	When does a full Moon rise, approximately?	
A)	At noon	
B)	At midnight	
C)	At sunrise	
D)	At sunset	

23.	Why is the period between two successive full Moons NOT equal to the Moon's orbital period, or sidereal month?	
A)	Because the Earth-Moon system is also orbiting the Sun	
B)	These two time intervals are not related because full Moon time depends on the Moon's rotation period about its own axis.	
C)	Because the Moon's orbit is inclined at about 5° to the Earth's orbital plane	
D)	Because the Moon's orbit is elliptical, and the Moon therefore moves irregularly around the Earth	

24.	A solar eclipse occurs on the Earth when	
A)	the Moon casts a shadow on the Earth.	
B)	the Earth casts a shadow on the Moon.	
C)	the Sun passes in front of the Moon.	
D)	the Moon passes behind the Sun.	

25.	What is the phase of the Moon during a total solar eclipse?	
A)	Crescent	
B)	First quarter	
C)	Full	
D)	New	

26.	In view of the elliptical orbits of the Earth and the Moon, which of the following conditions will result in the longest period of totality during a total solar eclipse?	
A)	The Earth is closest to the Sun when the Moon is farthest from the Earth.	
B)	The Earth is closest to the Sun when the Moon is closest to the Earth.	
C)	The Earth is farthest from the Sun when the Moon is farthest from the Earth.	
D)	The Earth is farthest from the Sun when the Moon is closest to the Earth.	

Answer Key

1.	B	
2.	B	
3.	D	
4.	C	
5.	C	
6.	D	
7.	D	
8.	B	
9.	B	
10.	D	
11.	D	
12.	A	
13.	A	
14.	A	
15.	C	
16.	D	
17.	A	
18.	A	
19.	A	
20.	B	
21.	D	
22.	D	
23.	A	
24.	A	
25.	D	
26.	D