Exam
Name___________________________________
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1)
Which of the following statements about parallax is not true?
1)
A)
You can demonstrate parallax simply by holding up a finger and looking at it alternately from
your left and right eyes.
B)
The technique of stellar parallax was used by Hubble to determine that the Andromeda
Galaxy (M 31) is about 2 million light–years away.
C)
Measurement of stellar parallax allows us to determine distances to nearby stars.
D)
Ancient astronomers were unable to measure parallax and used the absence of observed
parallax as an argument in favor of an Earth–centered universe.
E)
The existence of stellar parallax is direct proof that Earth orbits the Sun.
2)
If part of the full moon passes through Earth’s umbra, we will see a(n)
2)
A)
total lunar eclipse.
B)
partial solar eclipse.
C)
penumbral lunar eclipse.
D)
annular eclipse.
E)
partial lunar eclipse.
3)
Which of the following statements about constellations is false?
3)
A)
There are only 88 official constellations.
B)
Most constellations will be unrecognizable hundreds of years from now.
C)
Some constellations can be seen from both the Northern and Southern hemispheres.
D)
Some constellations can be seen in both the winter and summer.
E)
It is possible to see all the constellations from Earth’s equator.
4)
How many arcminutes are in one degree?
4)
A)
360
B)
100
C)
60
D)
10,000
E)
3600
5)
What is the saros cycle?
5)
A)
the annual cycle of the seasons
B)
the 26,000–year cycle of the Earth’s precession
C)
the roughly one–month cycle of lunar phases in the sky
D)
the roughly 18–year cycle over which the pattern of eclipses repeats
6)
Which of the following statements does not use the term angular size or angular distance correctly?
6)
A)
The angular size of the Sun is about the same as that of the Moon.
B)
You can use your outstretched hand against the sky to estimate angular sizes and angular
distances.
C)
The angular distance between those two bright stars in the sky is about 2 meters.
D)
The angular distance between those two houses in the distance is 30 degrees.
7)
What conditions are required for a lunar eclipse?
7)
A)
The phase of the Moon must be full, and the nodes of the Moon’s orbit must be nearly aligned
with Earth and the Sun.
B)
The phase of the Moon must be new, and the nodes of the Moon’s orbit must be nearly
aligned with Earth and the Sun.
C)
The phase of the Moon must be new, and the Moon’s orbital plane must lie in the ecliptic.
D)
The phase of the Moon must be full, and the Moon’s orbital plane must lie in the ecliptic.
E)
The phase of the Moon can be new or full, and the nodes of the Moon’s orbit must be nearly
aligned with Earth and the Sun.
8)
If the Moon is 3rd quarter phase, what shape does it have in the sky?
8)
A)
a full circle
B)
a quarter circle
C)
a half circle
D)
nothing (It is impossible to view a 3rd quarter moon.)
9)
The precession of the Moon’s nodes means that
9)
A)
there are never two solar eclipses in the same year.
B)
there is a solar eclipse every 6 months.
C)
the eclipse seasons occur less than 6 months apart.
D)
the vernal equinox will be in Aquarius in a few hundred years.
E)
there is a lunar eclipse every 6 months.
C
10)
We describe a location on Earth’s surface by stating its ________.
10)
A)
latitude and direction
B)
latitude and longitude
C)
altitude and direction (or azimuth)
D)
meridian and longitude
B
11)
An angle of 1 arcsecond is ________.
11)
A)
slightly more than the width of a basketball held at arm’s length
B)
about the width of a finger held at arm’s length
C)
less than the thickness of a human hair held at arm’s length
D)
about the width of your fist held at arm’s length
C
C
12)
Suppose Earth’s axis tilt was significantly greater than its current 23.5 degrees, but Earth’s rotation
period and orbital period were unchanged. Which statement below would not be true?
12)
A)
Polaris would not be our North star.
B)
The length of each season (for example, the number of days from the summer solstice to the
fall equinox) would be significantly longer than it is now.
C)
The region of Earth where the Sun does not rise on the winter solstice would be larger
(extending farther south) than it is now.
D)
Summers and winters would be more severe (for example, hotter and colder, respectively)
than they are now.
13)
When we look into the band of light in our sky that we call the Milky Way, can we see distant
galaxies? Why or why not?
13)
A)
Yes, there are many other galaxies that we see inside the Milky Way.
B)
No, because the stars, gas, and dust of the Milky Way block us from seeing them.
C)
Yes, they appear as small, fuzzy patches on the other side of our galaxy.
D)
No, because there are only galaxies above and below the plane of the Milky Way.
14)
What is a circumpolar star?
14)
A)
a star that is visible from the Arctic or Antarctic circles
B)
a star that makes a daily circle around the celestial sphere
C)
a star that is close to the south celestial pole
D)
a star that is close to the north celestial pole
E)
a star that always remains above your horizon
15)
What causes the apparent retrograde motion of the planets?
15)
A)
When planets are farther from the Sun, they move slower than when they are nearer the Sun;
it is during this slower period that they appear to move backwards.
B)
Apparent retrograde motion is an illusion created by turbulence in Earth’s atmosphere.
C)
The other planets never really appear to move backward; the background stars shift due to
Earth’s revolution around the Sun.
D)
As Earth passes another planet, its gravitational pull slows down the other planet so that it
appears to be traveling backward.
E)
As Earth passes another planet, the other planet appears to move backward with respect to
the background stars, but the planet’s motion does not really change.
16)
If the Moon is relatively far from Earth, so that its umbra does not reach Earth, someone directly
behind the umbra will see
16)
A)
a penumbral lunar eclipse.
B)
no eclipse.
C)
a partial lunar eclipse.
D)
a partial solar eclipse.
E)
an annular eclipse.
17)
You experience night–time when
17)
A)
the Moon blocks the Sun‘s light.
B)
the Earth revolves 90 degrees in its orbit.
C)
the Earth’s axis precesses.
D)
the side of the Earth you occupy is facing away from the Sun.
18)
If the Sun passes almost in front of the center of our Milky Way Galaxy, it does so
18)
A)
only in 2012, at the end of the Mayan calendar.
B)
once a day.
C)
once a month.
D)
once a year.
19)
Which planet is moving most slowly around the Sun?
19)
A)
Venus
B)
Jupiter
C)
Earth
D)
They are all moving with the same speed around the Sun.
20)
How many arcseconds are in one arcminute?
20)
A)
360
B)
3600
C)
60
D)
100
E)
10,000
21)
Each choice below describes how a few astronomical phenomena are related to time periods.
Which list is entirely correct? (Careful: some lists are partially correct.)
21)
A)
Earth’s rotation defines a day.
The Sun’s rotation defines a week.
The Moon’s rotation defines a month.
Earth’s orbit defines a year.
B)
Earth’s rotation defines a day.
The saros cycle of eclipses defines a month.
Earth’s orbit defines a year.
Earth’s cycle of axis precession takes 26,000 years.
C)
Earth’s rotation defines a day.
The cycle of the Moon’s phases takes about a month.
Earth’s orbit defines a year.
Earth’s cycle of axis precession takes 26,000 years.
D)
Earth’s rotation defines a day.
The cycle of the Moon’s phases takes about a week.
Earth’s orbit defines a year.
Earth’s cycle of axis precession defines a month.
22)
Which of the following situations would result in the longest days during the summer? (Assume an
axis tilt of 0 degrees is an axis perpendicular to the ecliptic plane.)
22)
A)
axis tilt 0 degrees
B)
axis tilt –10 degrees
C)
axis tilt 23.5 degrees
D)
axis tilt 90 degrees
23)
Which of the following statements about the Moon is true?
23)
A)
The side of the Moon facing away from Earth is in perpetual darkness.
B)
The Moon is visible only at night.
C)
If you see a full moon from North America, someone in South America would see a new
moon.
D)
The Moon goes through a cycle of phases because it always has the same side facing Earth.
E)
The Moon’s distance from Earth varies during its orbit.
Answer:
24)
About how many stars are visible to the naked eye on a clear, dark night away from city lights?
24)
A)
a couple thousand
B)
a few dozen
C)
several million
D)
a few hundred billion
Answer:
25)
Which of the following never goes in retrograde motion?
25)
A)
the Sun
B)
Saturn
C)
Mars
D)
Venus
E)
Jupiter
Answer:
Answer:
26)
During the time that a planet is in its period of apparent retrograde motion, ________.
26)
A)
the planet moves backwards (clockwise as viewed from above Earth’s north pole) in its orbit
of the Sun
B)
over many days or weeks, the planet moves westward relative to the stars, rather than the
usual eastward relative to the stars
C)
the planet appears to rise in the west and set in the east, rather than the usual rising in the east
and setting in the west
D)
the planet is getting closer to the Sun in its orbit
27)
Lunar eclipses can occur only during a ________.
27)
A)
third quarter moon
B)
new moon
C)
first quarter moon
D)
full moon
28)
What do astronomers mean by a constellation?
28)
A)
A constellation is any random grouping of stars in the sky.
B)
A constellation is a region in the sky as seen from Earth.
C)
A constellation is a group of stars that are all located in about the same place in space.
D)
A constellation is a group of stars related through an ancient story.
29)
What is the ecliptic?
29)
A)
a half–circle extending from your horizon due north, through your zenith, to your horizon
due south
B)
the path the Sun appears to trace around the celestial sphere each year
C)
the Sun’s daily path from east to west in our sky
D)
the path traced by the Moon’s shadow on Earth during a solar eclipse
30)
You see a crescent Moon setting after the Sun sets. Is it waning or waxing?
30)
A)
can’t distinguish based on the information provided
B)
waxing
C)
waning
31)
What do we mean when we talk about the Milky Way in our sky?
31)
A)
the whitish patch of light we see when we look toward the center of the Milky Way Galaxy
B)
the bright stars of the constellations that lie along the ecliptic in our sky
C)
the patchy band of light that outlines the plane of the Milky Way Galaxy as seen from Earth
D)
the spiral–shaped galaxy in which we live
32)
Suppose you are facing north and you see the Big Dipper close to your northern horizon, with
Polaris (and the Little Dipper) above it. Where will you see the Big Dipper in six hours?
32)
A)
directly above Polaris
B)
still in the same place, below Polaris
C)
to the left of Polaris; that is, 90 degrees clockwise from its current position
D)
to the right of Polaris; that is, 90 degrees counterclockwise from its current position
33)
In which direction does a quarter moon rise?
33)
A)
east
B)
north
C)
south
D)
west
E)
The Moon becomes a quarter moon only after it has risen and changed phase.
Explanation:
34)
If you see Polaris directly overhead at midnight, you must be at
34)
A)
the South Pole.
B)
the North Pole.
C)
the equator.
D)
the Tropic of Cancer.
35)
If the Moon is 3rd quarter phase, when does it rise?
35)
A)
sunset
B)
midnight
C)
noon
D)
sunrise
E)
never
36)
Suppose you use the Southern Cross to determine that the south celestial pole appears 40 degrees
above your horizon. Then you must be located at ________.
36)
A)
latitude 40 degrees south
B)
longitude 40 degrees
C)
latitude 50 degrees south
D)
latitude 40 degrees north
37)
If the Moon rises around 3 A.M., its phase must be
37)
A)
first quarter.
B)
waxing crescent.
C)
third quarter.
D)
full.
E)
waning crescent.
38)
The Greeks rejected the notion that the Earth orbits the Sun. Why?
38)
A)
They believed that the Sun is a God.
B)
They could not measure how big the Earth was.
C)
They could not measure a change in stars’ positions on the sky.
D)
They weren’t as smart as we are.
39)
If the Moon is setting at noon, the phase of the Moon must be
39)
A)
first quarter.
B)
full.
C)
waxing crescent.
D)
waning crescent.
E)
third quarter.
40)
If the Earth’s rotation axis were tilted by 45 degrees instead of 23.5 degrees, what are some of the
implications, and why?
40)
A)
The seasons would be less extreme, because the surface of the Earth would be farther from the
Sun in the summer, and closer to the Sun in the winter.
B)
The seasons would be less extreme, because the Sun’s rays would be less direct in summer,
and more direct in winter.
C)
The seasons would be more extreme, because the Sun’s rays would be more direct in summer,
and less direct in winter.
D)
The seasons would be more extreme, because the surface of the Earth would be closer to the
Sun in the summer, and farther from the Sun in the winter.
41)
Your friend tells you that last night, they saw Mars high in the sky at midnight. You conclude that
41)
A)
Mars must be in retrograde.
B)
Mars must be at its farthest distance from the Earth.
C)
Your friend must be mistaken: Mars can never be seen at midnight.
D)
Mars must be at its closest distance from the Sun.
42)
During a lunar eclipse the Moon’s phase must be
42)
A)
3rd quarter.
B)
full.
C)
new.
D)
1st quarter.
43)
If our year were twice as long (that is, if Earth took twice as many days to complete each orbit
around the Sun), but Earth’s rotation period and axis tilt were unchanged, then ________.
43)
A)
stars would take twice as long to rise and set
B)
the four seasons would each be twice as long as they are now
C)
the Earth would not have seasons
D)
the cycle of precession would take 13,000 years instead of 26,000 years
44)
Suppose it is full moon. What phase of Earth would someone on the Moon see at this time?
44)
A)
new Earth
B)
first quarter Earth
C)
full Earth
D)
Earth does not go through phases as seen from the Moon.
45)
For most of history, the lack of observable stellar parallax was interpreted to mean that ________.
45)
A)
Earth is stationary at the center of the universe
B)
stars must all lie at the same distance from Earth, on the celestial sphere
C)
Galileo’s theories of the universe were essentially correct
D)
stars were too far away for parallax to be measured with available technology
46)
All the following statements are true. Which one explains the reason that there is not a solar eclipse
at every new moon?
46)
A)
The orbital plane of the Moon is tilted slightly (by about 5 degrees) to the ecliptic plane.
B)
The Moon is only about 1/4 as large as Earth in diameter.
C)
The Moon goes through a complete cycle of phases about every 29 1/2 days.
D)
The nodes of the moon’s orbit precess with an 18–year period.
47)
Has Polaris always been the “North Star”?
47)
A)
No, because the Milky Way blocked our line of site to it for a long time.
B)
Yes, because the stars are unchanging.
C)
No, because it is a young star that only formed a few hundred years ago.
D)
No, because the Earth’s axis slowly changes the direction it points.
48)
By locating the north celestial pole (NCP) in the sky, how can you determine your latitude?
48)
A)
The altitude of the NCP is the same as your distance from the North Pole.
B)
The direction of the NCP is the same as your latitude.
C)
The altitude of the NCP is your angular distance from the North Pole.
D)
The altitude of the NCP is the same as your latitude.
E)
The direction of the NCP is the angular distance from the North Pole.
D
49)
Which of the following is not a phase of the Moon?
49)
A)
first–quarter moon
B)
full moon
C)
third–quarter moon
D)
half moon
E)
new moon
D
50)
You observe a full moon rising at sunset. What will you see at midnight?
50)
A)
a full moon high in the sky
B)
a third quarter moon
C)
a first quarter moon
D)
a waning gibbous moon
A
D
51)
At approximately what time would a first quarter moon rise?
51)
A)
midnight
B)
noon
C)
6 P.M.
D)
6 A.M.
E)
9 A.M.
52)
What effect or effects would be most significant if the Moon’s orbital plane were exactly the same as
the ecliptic plane?
52)
A)
Solar eclipses would be much rarer.
B)
Solar eclipses would be much more frequent.
C)
Total solar eclipses would last much longer.
D)
both A and C
E)
both B and C
53)
In addition to the conditions required for any solar eclipse, what must also be true in order for you
to observe a total solar eclipse?
53)
A)
Earth must lie completely within the Moon‘s penumbra.
B)
The Moon’s penumbra must touch the area where you are located.
C)
Earth must lie completely within the Moon’s umbra.
D)
The Moon‘s umbra must touch the area where you are located.
E)
Earth must be near aphelion in its orbit of the Sun.
54)
Suppose you live in the United States and you see a crescent moon in your evening sky tonight.
What will a friend in South America see tonight?
54)
A)
Your friend won’t see the Moon tonight, because it is up only in the morning.
B)
Your friend will also see a crescent moon.
C)
Your friend will see a first quarter moon.
D)
Your friend will see a gibbous moon.
55)
What is the celestial sphere?
55)
A)
The celestial sphere is a model of how the stars are arranged in the sky relative to our Sun,
which is in the middle of the sphere.
B)
It represents a belief in an Earth–centered universe, and hence is no longer considered to have
any use.
C)
The celestial sphere is a representation of how the entire sky looks as seen from Earth.
D)
The celestial sphere is a model that shows the true locations in space of the Sun and a few
thousand of the nearest stars.
56)
Tonight, your telescope shows you RXJ1800, a galaxy, very near in the sky to the bright star Vega.
What can you conclude from this observation?
56)
A)
RXJ1800 and Vega will drift apart from each other on the sky, over a matter of nights.
B)
Vega orbits the center of mass of RXJ1800.
C)
RXJ1800 and Vega will set in the west, at very similar times.
D)
Vega and RXJ1800 must be very close to each other, less than a few light years.
C
57)
The Moon’s orbit around the Earth is tilted by about 5 degrees with respect to Earth’s orbit around
the Sun. As a result, the approximate number of solar eclipses that occur each year is
approximately
57)
A)
0.
B)
2.
C)
24.
D)
12.
B
58)
At approximately what time would a full moon be on your meridian?
58)
A)
9 A.M.
B)
noon
C)
6 P.M.
D)
midnight
E)
6 A.M.
D
C
59)
Why were ancient peoples unable to detect stellar parallax?
59)
A)
They could not see distant stars.
B)
They did not observe for long enough periods of time.
C)
They did not have the ability to measure very small angles.
D)
They did not look for it.
E)
They did detect it, but they rejected the observations.
60)
If we have a new moon today, when we will have the next full moon?
60)
A)
in about 1 month
B)
in about 1 week
C)
in about 6 months
D)
in about 2 weeks
D
61)
When someone on Earth observes the Moon in the first–quarter phase, someone on the Moon
facing Earth observes Earth in the
61)
A)
new Earth phase.
B)
crescent Earth phase.
C)
third–quarter Earth phase.
D)
first–quarter Earth phase.
E)
full Earth phase.
C
62)
Why is it summer in the Northern Hemisphere when it is winter in the Southern Hemisphere?
62)
A)
The Northern Hemisphere is closer to the Sun than the Southern Hemisphere.
B)
The Northern Hemisphere is tilted away from the Sun and receives more indirect sunlight.
C)
The Northern Hemisphere is “on top” of Earth and therefore receives more sunlight.
D)
The Northern Hemisphere is tilted toward the Sun and receives more direct sunlight.
E)
It isn’t; both hemispheres have the same seasons at the same time.
D
C
63)
The Sun’s path, as viewed from the equator, is highest in the sky on ________.
63)
A)
the summer solstice
B)
the spring and fall equinoxes
C)
the winter solstice
D)
the day when Earth is closest to the Sun
64)
The Andromeda Galaxy is faintly visible to the naked eye in the constellation Andromeda. Suppose
instead it were located in the same direction in space as the center of the Milky Way Galaxy (but
still at its current distance). How would it appear to the eye in that case?
64)
A)
It would be much brighter because it would be illuminated by the many stars in the center of
our galaxy.
B)
We could not see it at all.
C)
It would look about the same, but would be in the constellation Sagittarius instead of
Andromeda.
D)
It would look about the same, but it would be harder to pick out because its cloud–like
appearance would make it blend in with the cloud–like appearance of the Milky Way in our
sky.
65)
Which of the following statements about the celestial equator is true at all latitudes?
65)
A)
It extends from your horizon due north, through your zenith, to your horizon due south.
B)
It lies along the band of light we call the Milky Way.
C)
It represents an extension of Earth’s equator onto the celestial sphere.
D)
It cuts the dome of your local sky exactly in half.
E)
It extends from your horizon due east, through your zenith, to your horizon due west.
66)
When are eclipse seasons?
66)
A)
in the spring and fall
B)
in the summer and winter
C)
when the nodes of the Moon’s orbit are nearly aligned with the Sun
D)
during an eclipse
E)
when Earth, the Sun, and the Moon are exactly aligned for an eclipse
67)
What makes the North Star, Polaris, special?
67)
A)
It appears very near the north celestial pole.
B)
It is the star directly on your northern horizon.
C)
It is the brightest star in the sky.
D)
It is the star straight overhead.
E)
It can be used to determine your longitude on Earth.
68)
Suppose you see a photo showing Jupiter half in sunlight and half in shadow (that is, a first quarter
Jupiter). This photo might have been taken by ________.
68)
A)
the Galileo spacecraft that orbited Jupiter in the 1990s
B)
the Keck telescope on Mauna Kea, Hawaii
C)
the Arecibo radio telescope in Puerto Rico
D)
the Hubble Space Telescope (which orbits Earth)
69)
When traveling north from the United States into Canada, you‘ll see the North Star (Polaris) getting
________.
69)
A)
lower in the sky
B)
brighter
C)
dimmer
D)
higher in the sky
70)
What conditions are required for a solar eclipse?
70)
A)
The phase of the Moon must be full, and the nodes of the Moon’s orbit must be nearly aligned
with Earth and the Sun.
B)
The phase of the Moon must be new, and the Moon’s orbital plane must lie in the ecliptic.
C)
The phase of the Moon must be new, and the nodes of the Moon’s orbit must be nearly
aligned with Earth and the Sun.
D)
The phase of the Moon can be new or full, and the nodes of the Moon’s orbit must be nearly
aligned with Earth and the Sun.
E)
The phase of the Moon must be full, and the Moon’s orbital plane must lie in the ecliptic.
Explanation:
71)
“Gibbous” means a nearly full moon. If I see a waxing gibbous moon tonight, what moon phase will
I see in one week?
71)
A)
waning crescent
B)
waxing crescent
C)
waning gibbous
D)
waxing gibbous
72)
In any particular place on Earth, certain constellations are visible in the evening only at certain
times of the year because ________.
72)
A)
during some times of year, some constellations drop below the southern horizon
B)
on any particular night, we can only see stars that are directly opposite (180 degrees away
from) the Sun in the sky
C)
some constellations are circumpolar
D)
our evening view of space depends on where Earth is located in its orbit around the Sun
73)
If the Moon is setting at 6 A.M., the phase of the Moon must be
73)
A)
full.
B)
waning crescent.
C)
new.
D)
first quarter.
E)
third quarter.
74)
RXJ1800, a galaxy, lies very near in the sky to the bright star Vega. What is the best explanation for
them appearing close together?
74)
A)
They coincidentally lie along the same line of sight.
B)
Vega orbits the center of mass of RXJ1800.
C)
Vega must have recently formed in RXJ1800 and been ejected.
D)
Their random motions have caused RXJ1800 and Vega to drift to within a few light–years of
each other.
75)
Which of the following statements about lunar phases is true?
75)
A)
The time from one new moon to the next new moon is the same as the time from first–quarter
moon to third–quarter moon.
B)
The time between new moons is two weeks.
C)
The full moon sometimes rises around midnight.
D)
It is possible to have two full moons during January, but not during February.
E)
It is possible to have two full moons during November, but not during December.
76)
Which of the following correctly describes the meridian in your local sky?
76)
A)
a half–circle extending from your horizon due east, through your zenith, to your horizon due
west
B)
the point directly over your head
C)
a half–circle extending from your horizon due north, through your zenith, to your horizon
due south
D)
a half–circle extending from your horizon due east, through the north celestial pole, to your
horizon due west
C
77)
We cannot see a new moon in our sky because ________.
77)
A)
a new moon is quite near the Sun in the sky
B)
no sunlight is illuminating the Moon
C)
it is above the horizon during the daytime
D)
it is obscured by Earth’s shadow
A
78)
Ancient people who knew the saros cycle could
78)
A)
predict when they’d see the next total solar eclipse in their area.
B)
predict when an eclipse would happen, but not necessarily what type and where it would be
visible.
C)
completely predict every lunar eclipse.
D)
predict what type of eclipse would occur.
E)
completely predict every solar eclipse.
B
D
79)
Stars that are visible in the local sky on any clear night of the year, at any time of the night, are
called ________.
79)
A)
circumpolar
B)
bright
C)
seasonal
D)
celestial
80)
How many arcseconds are in one degree?
80)
A)
3,600
B)
60
C)
100
D)
360
E)
10,000
81)
Which of the following conditions must exist for a solar eclipse to occur?
81)
A)
Moon phase is full, and the Moon is passing through the Earth’s orbital plane.
B)
Moon phase is new, and the Moon is passing through the Earth’s orbital plane.
C)
The only condition is that the phase of the Moon must be new.
D)
The only condition is that the phase of the Moon must be full.
82)
Which of the following statements about stellar parallax is true?
82)
A)
Stellar parallax was first observed by ancient Greek astronomers.
B)
We observe all stars to exhibit at least a slight amount of parallax.
C)
The closer a star is to us, the more parallax it exhibits.
D)
The amount of parallax we see depends on how fast a star is moving relative to us.
E)
It takes at least 10 years of observation to measure a star’s parallax.
83)
If it is midnight in New York, it is
83)
A)
midnight everywhere.
B)
midday in Rio de Janeiro, Brazil.
C)
daytime in Sydney, Australia.
D)
midnight in Sydney, Australia.
E)
midnight in Los Angeles.
84)
If the Moon is setting at noon, then it rose at
84)
A)
6 P.M.
B)
noon.
C)
6 A.M.
D)
midnight.
E)
9 A.M.
85)
If the Moon is rising at midnight, the phase of the Moon must be
85)
A)
first quarter.
B)
waxing crescent.
C)
full.
D)
waning crescent.
E)
third quarter.
86)
Orion is visible on winter evenings but not summer evenings because of
86)
A)
baseball on television.
B)
the location of Earth in its orbit.
C)
the precession of Earth’s axis.
D)
interference from the full moon.
E)
the tilt of Earth’s axis.
87)
Which of these (hypothetical) modifications would cause lunar eclipses to happen once per month?
87)
A)
Change the Moon’s orbital plane so it tilts the opposite way.
B)
Change the orbital plane of the Moon so it lies in the same plane as Earth’s orbit around the
Sun.
C)
Make the Moon orbit the Earth twice as fast.
D)
Relocate the Moon to twice its current distance from the Earth.
88)
Which of the following statements about the celestial sphere is not true?
88)
A)
When we look in the sky, the stars all appear to be located on the celestial sphere.
B)
The Earth is placed at the center of the celestial sphere.
C)
The celestial sphere does not exist physically.
D)
The “celestial sphere” is another name for our universe.
89)
We can’t detect stellar parallax with naked–eye observations. Which of the following would make
parallax easier to observe?
89)
A)
slowing down Earth‘s orbital motion
B)
Speeding up the precession of Earth’s axis
C)
getting away from streetlights
D)
speeding up Earth’s orbital motion
E)
increasing the size of Earth’s orbit
90)
Which of the following statements is true?
90)
A)
Both the Northern and Southern hemispheres receive the same amount of sunlight on the
equinoxes.
B)
The Southern Hemisphere receives the most direct sunlight on the summer solstice.
C)
The Northern Hemisphere receives the most direct sunlight on the summer solstice.
D)
Both the Northern and Southern hemispheres receive the same amount of sunlight on the
solstices.
E)
Both A and C are true.
91)
Which of the following statements about circumpolar stars is true at all latitudes?
91)
A)
They make relatively small circles, traveling clockwise around the north celestial pole.
B)
You cannot see them from the Southern Hemisphere.
C)
Like all other stars, they rise in the east and set in the west.
D)
They are the stars close to the north celestial pole.
E)
They always remain above your horizon.
92)
The point directly over your head is called ________.
92)
A)
the North Star
B)
the meridian
C)
the zenith
D)
the north celestial pole
C
93)
What is stellar parallax?
93)
A)
It is the slight back–and–forth shifting of star positions that occurs as we view the stars from
different positions in Earth’s orbit of the Sun.
B)
It is the daily rise and set of the stars.
C)
It describes the fact that stars are actually moving relative to one another, even though to our
eyes the stars appear fixed in the constellations.
D)
It is the change in the set of constellations that we see at different times of year in the evening
sky.
A
94)
It’s 6 a.m. and the Moon is at its highest point in your sky (crossing the meridian). What is the
Moon’s phase?
94)
A)
new
B)
third quarter
C)
first quarter
D)
full
B
E
95)
During the period each year when we see Mars undergoing apparent retrograde motion in our sky,
what is really going on in space?
95)
A)
Earth is catching up with and passing by Mars in their respective orbits.
B)
Earth and Mars are getting closer together.
C)
Earth and Mars are on opposite sides of the Sun.
D)
Mars is moving around the Sun in the opposite direction from which Earth is moving around
the Sun.
96)
You are standing on Earth’s equator. Which way is Polaris, the North star?
96)
A)
directly overhead
B)
30 degrees up, due West
C)
on the northern horizon
D)
The answer depends on whether it’s winter or summer.
E)
The answer depends on what time of day (or night) it is.
C
97)
How does Earth’s varying distance from the Sun affect our seasons?
97)
A)
It doesn’tEarth’s orbital distance plays no significant role in the seasons.
B)
It makes summer warmer in the Northern Hemisphere than in the Southern Hemisphere.
C)
It causes the seasons to be more extreme than they would be if the Earth’s distance from the
Sun were always the same.
D)
It is responsible for the fact that the seasons are opposite in the Northern and Southern
hemispheres.
A
98)
What happens during the apparent retrograde motion of a planet?
98)
A)
The planet moves through constellations that are not part of the zodiac.
B)
The planet moves backward in its orbit around the Sun.
C)
The planet appears to move eastward with respect to the stars over a period of many nights.
D)
The planet moves backward through the sky.
E)
The planet rises in the west and sets in the east.
C
A
99)
The Moon is nearly tidally locked to the Earth, which means the Moon‘s rotation period is almost
the same as its orbital period. If you were camped at the equator of the Moon, you would
experience (approximately)
99)
A)
sunshine (day) all the time.
B)
sunshine all the time, except when the Earth blocks the Sun.
C)
(14 × 24) hours of darkness followed by (14 × 24) hours of sunshine.
D)
14 hours of darkness followed by 14 hours of sunshine.
100)
If you are located in the Northern Hemisphere, which of the following correctly describes a
relationship between the sky and your location?
100)
A)
The altitude of the north celestial pole equals your latitude.
B)
The altitude of the north celestial pole equals your longitude.
C)
The altitude of the celestial equator equals your latitude.
D)
The longitude of the north celestial pole is circumpolar, and therefore crosses your zenith at
the meridian.
101)
Which of the following best describes why we have seasons on Earth?
101)
A)
The tilt of Earth’s axis causes the northern hemisphere to be closer to the Sun than the
southern hemisphere in summer, and vice versa in winter.
B)
Earth’s elliptical orbit means we are closer to the Sun and therefore receive more intense
sunlight at some times of year than at others.
C)
The varying speed of Earth in its orbit around the Sun gives us summer when we are moving
fastest and winter when we are moving slowest.
D)
The tilt of Earth’s axis causes different portions of the Earth to receive more or less direct
sunlight at different times of year.
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
The choices below are for the following questions. For each question, choose the letter for the real motion that is responsible for the
apparent motion as seen from Earth.
A. Earth rotates once each day.
B. Earth revolves around the Sun once each year.
C. The direction of Earth‘s axis in space precesses with a period of 26,000 years.
D. Stars appear to move randomly in the local solar neighborhood.
E. The universe is expanding.
102)
The Moon rises in the east and sets in the west.
102)
103)
Consider the following statement, and explain whether or not it is sensible: When I looked
into the dark fissure of the Milky Way with my binoculars, I saw what must have been a
cluster of distant galaxies.
103)
The choices below are for the following questions. For each question, choose the letter for the real motion that is responsible for the
apparent motion as seen from Earth.
A. Earth rotates once each day.
B. Earth revolves around the Sun once each year.
C. The direction of Earth‘s axis in space precesses with a period of 26,000 years.
D. Stars appear to move randomly in the local solar neighborhood.
E. The universe is expanding.
104)
In the year A.D. 15,000, Vega will be a better north star than Polaris.
104)
C
105)
Consider the following statement, and explain whether or not it is sensible: Although all
the known stars appear to rise in the east and set in the west, we might someday discover a
star that will appear to rise in the west and set in the east.
105)
106)
Consider the following statement, and explain whether or not it is sensible: My sign is Ursa
Major because the Sun was in Ursa Major when I was born.
106)
A
107)
Consider the following statement, and explain whether or not it is sensible: If you had a
very fast spaceship, you could travel to the celestial sphere in about 100 years.
107)
The choices below are for the following questions. For each question, choose the letter for the real motion that is responsible for the
apparent motion as seen from Earth.
A. Earth rotates once each day.
B. Earth revolves around the Sun once each year.
C. The direction of Earth‘s axis in space precesses with a period of 26,000 years.
D. Stars appear to move randomly in the local solar neighborhood.
E. The universe is expanding.
108)
The Big Dipper will look different 100,000 years from now than it does today.
108)
109)
Suppose you lived on the Moon near the center of the face that we see from Earth. During
the phase of full moon, what phase would you see for Earth? Would it be day or night at
your home?
109)
110)
At what altitude and in what direction in your sky does the north or south celestial pole
appear?
110)
The choices below are for the following questions. For each question, choose the letter for the real motion that is responsible for the
apparent motion as seen from Earth.
A. Earth rotates once each day.
B. Earth revolves around the Sun once each year.
C. The direction of Earth‘s axis in space precesses with a period of 26,000 years.
D. Stars appear to move randomly in the local solar neighborhood.
E. The universe is expanding.
111)
Polaris will no longer be the North Star 1,000 years from now.
111)
112)
Suppose the distance to the Moon were twice its actual value. Could we still have solar
eclipses? If so, what type(s)?
112)
113)
Why is the Moon not completely invisible (it appears as a very deep red color) to the naked
eye during a total lunar eclipse?
113)
114)
Answer each of the following questions for our local sky.
A. Where is the north celestial pole in our sky?
B. Is Polaris a circumpolar star in our sky? Explain.
C. Describe the meridian in our sky.
D. Describe the celestial equator in our sky.
114)
The choices below are for the following questions. For each question, choose the letter for the real motion that is responsible for the
apparent motion as seen from Earth.
A. Earth rotates once each day.
B. Earth revolves around the Sun once each year.
C. The direction of Earth‘s axis in space precesses with a period of 26,000 years.
D. Stars appear to move randomly in the local solar neighborhood.
E. The universe is expanding.
115)
A million years from now, Alpha Centauri will no longer be the nearest star system to our
own.
115)
116)
What would you see if you were on the near side of the Moon during a lunar eclipse?
116)
117)
Suppose you lived on the Moon near the center of the face that we see from Earth. During
the phase of new moon, what phase would you see for Earth? Would it be day or night at
your home?
117)
118)
Consider the following statement, and explain whether or not it is sensible: Last night I
saw Mars move westward through the sky in its apparent retrograde motion.
118)
119)
If Earth’s axis had no tilt, would we still have seasons? Why or why not?
119)
120)
Suppose you lived on the Moon near the center of the face that we see from Earth. At what
phase of the Moon would you see sunset? What phase of Earth would you see at this time?
120)
121)
Consider the following statement, and explain whether or not it is sensible: Last night I
saw Jupiter in the constellation Ursa Major.
121)
122)
Why does the Milky Way appear as a band of light in the sky?
122)
123)
Consider the following statement, and explain whether or not it is sensible: If you lived on
the Moon, you’d see full Earth when we see new moon.
123)
The choices below are for the following questions. For each question, choose the letter for the real motion that is responsible for the
apparent motion as seen from Earth.
A. Earth rotates once each day.
B. Earth revolves around the Sun once each year.
C. The direction of Earth‘s axis in space precesses with a period of 26,000 years.
D. Stars appear to move randomly in the local solar neighborhood.
E. The universe is expanding.
124)
The stars visible at night change over the course of the year.
124)
125)
What would you see on Earth if you were on the near side of the Moon during a solar
eclipse?
125)
The choices below are for the following questions. For each question, choose the letter for the real motion that is responsible for the
apparent motion as seen from Earth.
A. Earth rotates once each day.
B. Earth revolves around the Sun once each year.
C. The direction of Earth‘s axis in space precesses with a period of 26,000 years.
D. Stars appear to move randomly in the local solar neighborhood.
E. The universe is expanding.
126)
The stars visible just after sunset are different from those visible just before sunrise.
126)
127)
The stars of Orion’s belt rise in the east and set in the west.
127)
128)
Suppose you lived on the Moon near the center of the face that we see from Earth. At what
phase of the Moon would you see sunrise? What phase of Earth would you see at this
time?
128)
TRUE/FALSE. Write ‘T’ if the statement is true and ‘F’ if the statement is false.
129)
It is possible to see the third–quarter moon near the western horizon at sunrise.
129)
130)
A lunar eclipse occurs only when the Moon is new.
130)
131)
You can find the tilt of Earth’s axis by measuring the angle between your horizon and the North
Star.
131)
132)
The Moon and the Sun are approximately the same angular size.
132)
133)
A solar eclipse occurs only when the Moon is new.
133)
134)
At midnight it is sometimes possible to observe the crescent moon on the meridian.
134)
135)
If you lived on the Moon, you’d see full Earth when we see new moon.
135)
136)
The Moon and Sun are approximately the same physical size.
136)
137)
The Milky Way can be seen only from the Northern Hemisphere.
137)
138)
It is possible to see the full moon rising just before sunrise.
138)
139)
It is possible to view the Moon in first–quarter phase the day after a total lunar eclipse.
139)
140)
The seasons on Earth are caused by its elliptical orbit around the Sun.
140)
141)
In South Africa, it’s usually quite warm around the time of the December solstice and quite cool
around the time of the Junesolstice.
141)
ESSAY. Write your answer in the space provided or on a separate sheet of paper.
142)
The Sidereal Day: Using your wristwatch and observations of the night sky over the course of a few weeks, how
can you demonstrate to a friend that 24 hours cannot be the true rotation period of the Earth (often called the
sidereal day)? What assumptions do you make in this argument?
143)
Cognitive Dissonance? You are talking to a friend who insists that the seasons are caused by a varying Earth–Sun
distance over the course of a year. What other fact does your friend likely know that completely contradicts this
view of how the seasons are caused? Can you think of other examples of two beliefs that many people feel are
both true but which completely contradict each other? How does science view this situation?
144)
Models in Science: Models play a central role in astronomy and science in general. Two models used extensively
in this chapter are the celestial sphere and the heliocentric (Sun–centered) model for the solar system.
Astronomers clearly believe that the celestial sphere model is false and the heliocentric model is true. Given this,
why do you think astronomers persist in using the celestial sphere model to describe the night sky?
145)
Scientific Reasoning: The scientific method requires that we put any hypothesis about how the universe works to
the test by conducting observations of the natural world. Consider the Greek reaction to the idea of a
heliocentric (Sun–centered) solar system. Why did most Greeks reject this hypothesis in favor of the geocentric
(Earth–centered) model? Do you think that the Greeks were following a scientific form of reasoning to reach this
conclusion? Does the fact that the Greeks reached the wrong conclusion affect your answer?
Answer Key
Testname: C2
Answer Key
Testname: C2
Answer Key
Testname: C2
Answer Key
Testname: C2