Astronomy Chapter 2

In South Africa, it's usually quite warm around the time of the December solstice and quite cool around the time of the June solstice. T or F

True

You can find the tilt of Earth's axis by measuring the angle between your horizon and the North Star. T or F

True

If the Moon is rising at midnight, the phase of the Moon must be A) full. B) first quarter. C) third quarter. D) waning crescent. E) waxingcrescent.

C

If the Moon is setting at 6 A.M., the phase of the Moon must be A) first quarter. B) third quarter. C) full. D) new. E) waningcrescent.

C

Orion is visible on winter evenings but not summer evenings because of A) interference from the full moon. B) the tilt of Earth's axis. C) the location of Earth in its orbit. D) the precession of Earth's axis E) baseball on television

C

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 ________. A) latitude 40 degrees north B) latitude 50 degrees south C) latitude 40 degrees south D) longitude 40 degrees

C

What happens during the apparent retrograde motion of a planet? A) The planet rises in the west and sets in the east. B) The planet appears to move westward with respect to the stars over a period of many nights. C) The planet moves backward through the sky. D) The planet moves through constellations that are not part of the zodiac.

C

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

C

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

C

When traveling north from the United States into Canada, you'll see the North Star (Polaris) getting ________. A) brighter B) dimmer C) higher in the sky D) lower in the sky

C

By locating the north celestial pole (NCP) in the sky, how can you determine your latitude? A) The altitude of the NCP is the same as your latitude. B) The altitude of the NCP is your angular distance from the North Pole. C) The direction of the NCP is the same as your latitude. D) The direction of the NCP is the angular distance from the North Pole. E) The altitude of the NCP is the same as your distance from the North Pole.

A

If it is midnight in New York, it is daytime in Sydney, Australia. midnight in Sydney, Australia. midnight in Los Angeles. midday in Rio de Janeiro, Brazil. midnight everywhere.

A

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) some constellations are circumpolar D) on any particular night, we can only see stars that are directly opposite (180 degrees away from) the Sun in the sky

A

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) to the right of Polaris; that is, 90 degrees counterclockwise from its current position B) to the left of Polaris; that is, 90 degrees clockwise from its current position C) directly above Polaris D) still in the same place, below Polaris

A

We can't detect stellar parallax with naked-eye observations. Which of the following would make parallax easier to observe? A) increasing the size of Earth's orbit B) speeding up Earth's orbital motion C) slowing down Earth's orbital motion D) Speeding up the precession of Earth's axis E) getting away from streetlights

A

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

A

What is the celestial sphere? A) The celestial sphere is a representation of how the entire sky looks as seen from Earth. B) The celestial sphere is a model that shows the true locations in space of the Sun and a few thousand of the nearest stars. C) 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. D) It represents a belief in an Earth-centered universe, and hence is no longer considered to have any use.

A

What is the ecliptic? A) the path the Sun appears to trace around the celestial sphere each year B) the Sun's daily path from east to west in our sky C) the path traced by the Moon's shadow on Earth during a solar eclipse D) a half-circle extending from your horizon due north, through your zenith, to your horizon due south

A

Which of the following never goes in retrograde motion? A) the Sun B) Venus C) Mars D) Jupiter E) Saturn

A

Your friend tells you that last night, they saw Mars high in the sky at midnight. You conclude that A) Mars must be in retrograde. B) Your friend must be mistaken: Mars can never be seen at midnight. C) Mars must be at its farthest distance from the Earth. D) Mars must be at its closest distance from the Sun.

A

If part of the full moon passes through Earth's umbra, we will see a(n) total lunar eclipse. penumbral lunar eclipse. partial lunar eclipse. partial solar eclipse. annular eclipse.

C

About how many stars are visible to the naked eye on a clear, dark night away from city lights? A) a few dozen B) a couple thousand C) several million D) a few hundred billion

B

All the following statements are true. Which one explains the reason that there is not a solar eclipse at every new moon? A) The nodes of the moon's orbit precess with an 18-year period. B) The orbital plane of the Moon is tilted slightly (by about 5 degrees) to the ecliptic plane. C) The Moon is only about 1/4 as large as Earth in diameter. D) The Moon goes through a complete cycle of phases about every 29 1/2 days.

B

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

B

The Sun's path, as viewed from the equator, is highest in the sky on ________. A) the winter solstice B) the spring and fall equinoxes C) the summer solstice D) the day when Earth is closest to the Sun

B

What conditions are required for a solar eclipse? A) 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. B) 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. C) 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. D) The phase of the Moon must be new, and the Moon's orbital plane must lie in the ecliptic. E) The phase of the Moon must be full, and the Moon's orbital plane must lie in the ecliptic.

B

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

B

Which of the following statements does not use the term angular size or angular distance correctly? A) The angular distance between those two houses in the distance is 30 degrees. B) The angular distance between those two bright stars in the sky is about 2 meters. C) The angular size of the Sun is about the same as that of the Moon. D) You can use your outstretched hand against the sky to estimate angular sizes and angular distances.

B

Which planet is moving most slowly around the Sun? A) Earth B) Jupiter C) Venus D) They are all moving with the same speed around the Sun.

B

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

B

You are standing on Earth's equator. Which way is Polaris, the North star? A) 30 degrees up, due West B) on the northern horizon C) directly overhead D) The answer depends on whether it's winter or summer. E) The answer depends on what time of day (or night) it is.

B

During the period each year when we see Mars undergoing apparent retrograde motion in our sky, what is really going on in space? A) Mars is moving around the Sun in the opposite direction from which Earth is moving around the Sun. B) Earth and Mars are getting closer together. C) Earth is catching up with, and passing by, Mars in their respective orbits. D) Earth and Mars are on opposite sides of the Sun.

C

During the time that a planet is in its period of apparent retrograde motion, ________. A) the planet moves backwards (clockwise as viewed from above Earth's north pole) in its orbit of the Sun B) 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 C) over many days or weeks, the planet moves westward relative to the stars, rather than the usual eastward relative to the stars D) the planet is getting closer to the Sun in its orbit

C

Has Polaris always been the "North Star"? A) Yes, because the stars are unchanging. B) No, because it is a young star that only formed a few hundred years ago. C) No, because the Earth's axis slowly changes the direction it points. D) No, because the Milky Way blocked our line of site to it for a long time.

C

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 ________. A) stars would take twice as long to rise and set B) the cycle of precession would take 13,000 years instead of 26,000 years C) the four seasons would each be twice as long as they are now D) the Earth would not have seasons

C

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

C

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) If you see a full moon from North America, someone in South America would see a new moon. C) The Moon's distance from Earth varies during its orbit. D) The Moon is visible only at night. E) The side of the Moon facing away from Earth is in perpetual darkness.

C

Why is it summer in the Northern Hemisphere when it is winter in the Southern Hemisphere? A) The Northern Hemisphere is closer to the Sun than the Southern Hemisphere. B) The Northern Hemisphere is "on top" of Earth and therefore receives more sunlight. C) The Northern Hemisphere is tilted toward the Sun and receives more direct sunlight. D) The Northern Hemisphere is tilted away from the Sun and receives more indirect sunlight. E) It isn't; both hemispheres have the same seasons at the same time.

C

If you see Polaris directly overhead at midnight, you must be at A) the equator. B) the South Pole. C) the Tropic of Cancer. D) the North Pole.

D

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? Earth must lie completely within the Moon's umbra. Earth must lie completely within the Moon's penumbra. Earth must be near aphelion in its orbit of the Sun. The Moon's umbra must touch the area where you are located. The Moon's penumbra must touch the area where you are located.

D

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

D

What causes the apparent retrograde motion of the planets? A) As Earth passes another planet, its gravitational pull slows down the other planet so that it appears to be traveling backward. B) 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. 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, the other planet appears to move backward with respect to the background stars, but the planet's motion does not really change. E) Apparent retrograde motion is an illusion created by turbulence in Earth's atmosphere.

D

At approximately what time would a full moon be on your meridian? A) 6 A.M. B) 9 A.M. C) noon D) 6 P.M. E) midnight

E

What conditions are required for a lunar eclipse? A) 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. B) 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. C) 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. D) The phase of the Moon must be new, and the Moon's orbital plane must lie in the ecliptic. E) The phase of the Moon must be full, and the Moon's orbital plane must lie in the ecliptic.

E

What effect or effects would be most significant if the Moon's orbital plane were exactly the same as the ecliptic plane? 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

E

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

E

Which of the following statements is true? A) Both the Northern and Southern hemispheres receive the same amount of sunlight on the equinoxes. B) Both the Northern and Southern hemispheres receive the same amount of sunlight on the solstices. C) The Northern Hemisphere receives the most direct sunlight on the summer solstice. D) The Southern Hemisphere receives the most direct sunlight on the summer solstice. E) Both A and C are true.

E