Deck 2: Discovering the Universe for Yourself

Question 1

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)

A)(14 × 24)hours of darkness followed by (14 × 24)hours of sunshine.
B)sunshine (day)all the time.
C)sunshine all the time, except when the Earth blocks the Sun.
D)14 hours of darkness followed by 14 hours of sunshine.

Answer 1

A

Question 2

How many arcminutes are in one degree?

A)360
B)60
C)3600
D)10,000
E)100

Answer 2

B

Question 3

Which of the following best describes why we have seasons on Earth?

A)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.
B)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.
C)The tilt of Earth's axis causes different portions of the Earth to receive more or less direct sunlight at different times of year.
D)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.

Answer 3

C

Question 4

What do astronomers mean by a constellation?

A)A constellation is a group of stars related through an ancient story.
B)A constellation is a group of stars that are all located in about the same place in space.
C)A constellation is a region in the sky as seen from Earth.
D)A constellation is any random grouping of stars in the sky.

Question 5

RXJ1800, a galaxy, lies very near in the sky to the bright star Vega. What is the best explanation for them appearing close together?

A)They coincidentally lie along the same line of sight.
B)Vega must have recently formed in RXJ1800 and been ejected.
C)Their random motions have caused RXJ1800 and Vega to drift to within a few light- years of each other.
D)Vega orbits the center of mass of RXJ1800.

Question 6

What conditions are required for a lunar eclipse?

A)The phase of the Moon must be full, and the Moon's orbital plane must lie in the ecliptic.
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 full, 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 new, and the Moon's orbital plane must lie in the ecliptic.

Question 7

If the Moon is relatively far from Earth, so that its umbra does not reach Earth, someone directly behind the umbra will see

A)a partial solar eclipse.
B)a penumbral lunar eclipse.
C)no eclipse.
D)an annular eclipse.
E)a partial lunar eclipse.

Question 8

Ancient people who knew the saros cycle could

A)completely predict every solar eclipse.
B)completely predict every lunar eclipse.
C)predict when they'd see the next total solar eclipse in their area.
D)predict what type of eclipse would occur.
E)predict when an eclipse would happen, but not necessarily what type and where it would be visible.

Question 9

You experience night- time when

A)the Earth revolves 90 degrees in its orbit.
B)the side of the Earth you occupy is facing away from the Sun.
C)the Earth's axis precesses.
D)the Moon blocks the Sun's light.

Question 10

For most of history, the lack of observable stellar parallax was interpreted to mean that .

A)stars must all lie at the same distance from Earth, on the celestial sphere
B)stars were too far away for parallax to be measured with available technology
C)Galileo's theories of the universe were essentially correct
D)Earth is stationary at the center of the universe

Question 11

All the following statements are true. Which one explains the reason that there is not a solar eclipse at every new moon?

A)The orbital plane of the Moon is tilted slightly (by about 5 degrees)to the ecliptic plane.
B)The Moon goes through a complete cycle of phases about every 29 1/2 days.
C)The nodes of the moon's orbit precess with an 18- year period.
D)The Moon is only about 1/4 as large as Earth in diameter.

Question 12

Which of the following statements about circumpolar stars is true at all latitudes?

A)You cannot see them from the Southern Hemisphere.
B)They always remain above your horizon.
C)They make relatively small circles, traveling clockwise around the north celestial pole.
D)They are the stars close to the north celestial pole.
E)Like all other stars, they rise in the east and set in the west.

Question 13

During the period each year when we see Mars undergoing apparent retrograde motion in our sky, what is really going on in space?

A)Earth and Mars are on opposite sides of the Sun.
B)Mars is moving around the Sun in the opposite direction from which Earth is moving around the Sun.
C)Earth is catching up with and passing by Mars in their respective orbits.
D)Earth and Mars are getting closer together.

Question 14

Stars that are visible in the local sky on any clear night of the year, at any time of the night, are called .

A)seasonal
B)celestial
C)circumpolar
D)bright

Question 15

"Gibbous" means a nearly full moon. If I see a waxing gibbous moon tonight, what moon phase will I see in one week?

A)waxing gibbous
B)waxing crescent
C)waning crescent
D)waning gibbous

Question 16

If the Moon is rising at midnight, the phase of the Moon must be

A)waning crescent.
B)third quarter.
C)full.
D)waxing crescent.
E)first quarter.

Question 17

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?

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.

Question 18

How many arcseconds are in one degree?

A)360
B)60
C)10,000
D)100
E)3,600

Question 19

What conditions are required for a solar eclipse?

A)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.
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 full, and the nodes of the Moon's orbit must be nearly aligned with Earth and the Sun.
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 must be new, and the Moon's orbital plane must lie in the ecliptic.

Question 20

What is a circumpolar star?

A)a star that is close to the north celestial pole
B)a star that is visible from the Arctic or Antarctic circles
C)a star that is close to the south celestial pole
D)a star that makes a daily circle around the celestial sphere
E)a star that always remains above your horizon

Question 21

Which of these (hypothetical)modifications would cause lunar eclipses to happen once per month?

A)Change the Moon's orbital plane so it tilts the opposite way.
B)Make the Moon orbit the Earth twice as fast.
C)Change the orbital plane of the Moon so it lies in the same plane as Earth's orbit around the Sun.
D)Relocate the Moon to twice its current distance from the Earth.

Question 22

You observe a full moon rising at sunset. What will you see at midnight?

A)a third quarter moon
B)a first quarter moon
C)a waning gibbous moon
D)a full moon high in the sky

Question 23

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

A)24.
B)12.
C)2)
D)0)

Question 24

Which of the following statements about stellar parallax is true?

A)The amount of parallax we see depends on how fast a star is moving relative to us.
B)Stellar parallax was first observed by ancient Greek astronomers.
C)It takes at least 10 years of observation to measure a star's parallax.
D)We observe all stars to exhibit at least a slight amount of parallax.
E)The closer a star is to us, the more parallax it exhibits.

Question 25

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?

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

Question 26

If the Moon is setting at noon, then it rose at

A)midnight.
B)6 A.M.
C)noon.
D)9 A.M.
E)6 P.M.

Question 27

We can't detect stellar parallax with naked- eye observations. Which of the following would make parallax easier to observe?

A)slowing down Earth's orbital motion
B)increasing the size of Earth's orbit
C)Speeding up the precession of Earth's axis
D)speeding up Earth's orbital motion
E)getting away from streetlights

Question 28

Suppose it is full moon. What phase of Earth would someone on the Moon see at this time?

A)new Earth
B)full Earth
C)first quarter Earth
D)Earth does not go through phases as seen from the Moon.

Question 29

An angle of 1 arcsecond is .

A)less than the thickness of a human hair held at arm's length
B)about the width of your fist held at arm's length
C)about the width of a finger held at arm's length
D)slightly more than the width of a basketball held at arm's length

Question 30

If the Earth's rotation axis were tilted by 45 degrees instead of 23.5 degrees, what are some of the implications, and why?

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 more extreme, because the Sun's rays would be more direct in summer, and less direct in winter.
C)The seasons would be less extreme, because the Sun's rays would be less direct in summer, and more 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.

Question 31

Which of the following statements does not use the term angular size or angular distance correctly?

A)The angular distance between those two bright stars in the sky is about 2 meters.
B)You can use your outstretched hand against the sky to estimate angular sizes and angular distances.
C)The angular size of the Sun is about the same as that of the Moon.
D)The angular distance between those two houses in the distance is 30 degrees.

Question 32

What is stellar parallax?

A)It is the change in the set of constellations that we see at different times of year in the evening sky.
B)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.
C)It is the daily rise and set of the stars.
D)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.

Question 33

We describe a location on Earth's surface by stating its _.

A)meridian and longitude
B)latitude and direction
C)latitude and longitude
D)altitude and direction (or azimuth)

Question 34

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?

A)Your friend will see a first quarter moon.
B)Your friend will see a gibbous moon.
C)Your friend won't see the Moon tonight, because it is up only in the morning.
D)Your friend will also see a crescent moon.

Question 35

Why were ancient peoples unable to detect stellar parallax?

A)They did not have the ability to measure very small angles.
B)They did not observe for long enough periods of time.
C)They could not see distant stars.
D)They did not look for it.
E)They did detect it, but they rejected the observations.

Question 36

What is the saros cycle?

A)the roughly 18- year cycle over which the pattern of eclipses repeats
B)the annual cycle of the seasons
C)the roughly one- month cycle of lunar phases in the sky
D)the 26,000- year cycle of the Earth's precession

Question 37

At approximately what time would a full moon be on your meridian?

A)midnight
B)6 P.M.
C)9 A.M.
D)6 A.M.
E)noon

Question 38

If you are located in the Northern Hemisphere, which of the following correctly describes a relationship between the sky and your location?

A)The longitude of the north celestial pole is circumpolar, and therefore crosses your zenith at the meridian.
B)The altitude of the celestial equator equals your latitude.
C)The altitude of the north celestial pole equals your latitude.
D)The altitude of the north celestial pole equals your longitude.

Question 39

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?

A)Vega orbits the center of mass of RXJ1800.
B)RXJ1800 and Vega will drift apart from each other on the sky, over a matter of nights.
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.

Question 40

Which of the following statements about the celestial sphere is not true?

A)When we look in the sky, the stars all appear to be located on the celestial sphere.
B)The celestial sphere does not exist physically.
C)The "celestial sphere" is another name for our universe.
D)The Earth is placed at the center of the celestial sphere.

Question 41

If the Moon is 3rd quarter phase, when does it rise?

A)sunrise
B)never
C)midnight
D)sunset
E)noon

Question 42

In which direction does a quarter moon rise?

A)south
B)east
C)west
D)north
E)The Moon becomes a quarter moon only after it has risen and changed phase.

Question 43

What makes the North Star, Polaris, special?

A)It can be used to determine your longitude on Earth.
B)It appears very near the north celestial pole.
C)It is the star directly on your northern horizon.
D)It is the brightest star in the sky.
E)It is the star straight overhead.

Question 44

What causes the apparent retrograde motion of the planets?

A)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.
B)Apparent retrograde motion is an illusion created by turbulence in Earth's atmosphere.
C)As Earth passes another planet, its gravitational pull slows down the other planet so that it appears to be traveling backward.
D)The other planets never really appear to move backward; the background stars shift due to Earth's revolution around the Sun.
E)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.

Question 45

If the Moon is 3rd quarter phase, what shape does it have in the sky?

A)a half circle
B)a full circle
C)a quarter circle
D)nothing (It is impossible to view a 3rd quarter moon.)

Question 46

If we have a new moon today, when we will have the next full moon?

A)in about 6 months
B)in about 1 week
C)in about 2 weeks
D)in about 1 month

Question 47

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.)

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.

Question 48

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.)

A)axis tilt - 10 degrees
B)axis tilt 23.5 degrees
C)axis tilt 0 degrees
D)axis tilt 90 degrees

Question 49

Orion is visible on winter evenings but not summer evenings because of

A)the location of Earth in its orbit.
B)interference from the full moon.
C)baseball on television.
D)the tilt of Earth's axis.
E)the precession of Earth's axis.

Question 50

Which of the following statements about the celestial equator is true at all latitudes?

A)It represents an extension of Earth's equator onto the celestial sphere.
B)It lies along the band of light we call the Milky Way.
C)It extends from your horizon due east, through your zenith, to your horizon due west.
D)It extends from your horizon due north, through your zenith, to your horizon due south.
E)It cuts the dome of your local sky exactly in half.

Question 51

We cannot see a new moon in our sky because .

A)it is above the horizon during the daytime
B)it is obscured by Earth's shadow
C)no sunlight is illuminating the Moon
D)a new moon is quite near the Sun in the sky

Question 52

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?

A)third quarter
B)new
C)full
D)first quarter

Question 53

What do we mean when we talk about the Milky Way in our sky?

A)the spiral- shaped galaxy in which we live
B)the patchy band of light that outlines the plane of the Milky Way Galaxy as seen from Earth
C)the whitish patch of light we see when we look toward the center of the Milky Way Galaxy
D)the bright stars of the constellations that lie along the ecliptic in our sky

Question 54

When someone on Earth observes the Moon in the first- quarter phase, someone on the Moon facing Earth observes Earth in the

A)full Earth phase.
B)new Earth phase.
C)third- quarter Earth phase.
D)crescent Earth phase.
E)first- quarter Earth phase.

Question 55

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?

A)It would look about the same, but would be in the constellation Sagittarius instead of Andromeda.
B)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.
C)We could not see it at all.
D)It would be much brighter because it would be illuminated by the many stars in the center of our galaxy.

Question 56

What is the ecliptic?

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

Question 57

Which planet is moving most slowly around the Sun?

A)Venus
B)Jupiter
C)Earth
D)They are all moving with the same speed around the Sun.

Question 58

Which of the following statements about the Moon is true?

A)The Moon goes through a cycle of phases because it always has the same side facing Earth.
B)The side of the Moon facing away from Earth is in perpetual darkness.
C)If you see a full moon from North America, someone in South America would see a new moon.
D)The Moon is visible only at night.
E)The Moon's distance from Earth varies during its orbit.

Question 59

The Sun's path, as viewed from the equator, is highest in the sky on .

A)the spring and fall equinoxes
B)the day when Earth is closest to the Sun
C)the winter solstice
D)the summer solstice

Question 60

When traveling north from the United States into Canada, you'll see the North Star (Polaris)getting .

A)dimmer
B)lower in the sky
C)brighter
D)higher in the sky

Question 61

Which of the following statements about lunar phases is true?

A)The time between new moons is two weeks.
B)The full moon sometimes rises around midnight.
C)It is possible to have two full moons during January, but not during February.
D)It is possible to have two full moons during November, but not during December.
E)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.

Question 62

If the Moon is setting at 6 A.M., the phase of the Moon must be

A)full.
B)third quarter.
C)waning crescent.
D)first quarter.
E)new.

Question 63

At approximately what time would a first quarter moon rise?

A)6 A.M.
B)midnight
C)noon
D)9 A.M.
E)6 P.M.

Question 64

Which of the following is not a phase of the Moon?

A)third- quarter moon
B)full moon
C)first- quarter moon
D)half moon
E)new moon

Question 65

Which of the following correctly describes the meridian in your local sky?

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 east, through the north celestial pole, to your horizon due west
D)a half- circle extending from your horizon due north, through your zenith, to your horizon due south

Question 66

Lunar eclipses can occur only during a .

A)new moon
B)full moon
C)third quarter moon
D)first quarter moon

Question 67

If you see Polaris directly overhead at midnight, you must be at

A)the South Pole.
B)the North Pole.
C)the Tropic of Cancer.
D)the equator.

Question 68

The precession of the Moon's nodes means that

A)there is a solar eclipse every 6 months.
B)the eclipse seasons occur less than 6 months apart.
C)there is a lunar eclipse every 6 months.
D)there are never two solar eclipses in the same year.
E)the vernal equinox will be in Aquarius in a few hundred years.

Question 69

Which of the following statements is true?

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.

Question 70

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 .

A)the Keck telescope on Mauna Kea, Hawaii
B)the Arecibo radio telescope in Puerto Rico
C)the Galileo spacecraft that orbited Jupiter in the 1990s
D)the Hubble Space Telescope (which orbits Earth)

Question 71

What happens during the apparent retrograde motion of a planet?

A)The planet appears to move eastward with respect to the stars over a period of many nights.
B)The planet moves through constellations that are not part of the zodiac.
C)The planet moves backward through the sky.
D)The planet moves backward in its orbit around the Sun.
E)The planet rises in the west and sets in the east.

Question 72

What is the celestial sphere?

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.

Question 73

If part of the full moon passes through Earth's umbra, we will see a(n)

A)annular eclipse.
B)total lunar eclipse.
C)partial lunar eclipse.
D)partial solar eclipse.
E)penumbral lunar eclipse.

Question 74

During a lunar eclipse the Moon's phase must be

A)new.
B)3rd quarter.
C)1st quarter.
D)full.

Question 75

In any particular place on Earth, certain constellations are visible in the evening only at certain times of the year because _.

A)our evening view of space depends on where Earth is located in its orbit around the Sun
B)during some times of year, some constellations drop below the southern horizon
C)on any particular night, we can only see stars that are directly opposite (180 degrees away from)the Sun in the sky
D)some constellations are circumpolar

Question 76

The point directly over your head is called _ .

A)the north celestial pole
B)the meridian
C)the zenith
D)the North Star

Question 77

How many arcseconds are in one arcminute?

A)360
B)60
C)100
D)10,000
E)3600

Question 78

Which of the following statements about constellations is false?

A)Some constellations can be seen in both the winter and summer.
B)Some constellations can be seen from both the Northern and Southern hemispheres.
C)There are only 88 official constellations.
D)Most constellations will be unrecognizable hundreds of years from now.
E)It is possible to see all the constellations from Earth's equator.

Question 79

If it is midnight in New York, it is

A)midnight in Los Angeles.
B)midnight everywhere.
C)midnight in Sydney, Australia.
D)midday in Rio de Janeiro, Brazil.
E)daytime in Sydney, Australia.

Question 80

Has Polaris always been the "North Star"?

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.