Ast Ch 2

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 latitude 40 degrees north. latitude 50 degrees south. longitude 40 degrees. latitude 40 degrees south.

latitude 40 degrees south.

We can describe a position on Earth's surface by stating its altitude and direction. latitude and direction. latitude and longitude. meridian and longitude. altitude and azimuth.

latitude and longitude.

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

on the northern horizon

When are eclipse seasons? when Earth and the Sun are aligned with one another when the nodes of the Moon's orbit are nearly aligned with the Sun during an eclipse in the spring and fall in the summer and winter

when the nodes of the Moon's orbit are nearly aligned with the Sun

What is the Saros cycle? the 18-year cycle over which the pattern of eclipses repeats the roughly 6-month period between eclipse seasons the period between total solar eclipses the period between a total solar eclipse and a total lunar eclipse the period between eclipses

the 18-year cycle over which the pattern of eclipses repeats

At approximately what time would a full Moon be on your meridian? noon 6 A.M. midnight 9 A.M. 6 P.M.

Midnight

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

We could not see it at all.

How many arcseconds are in 1°? 100 60 10,000 3,600 360

3,600

What causes the apparent retrograde motion of the planets? The other planets never really appear to move backward; the background stars shift due to Earth's revolution around the Sun. 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. 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 actually change. Apparent retrograde motion is an illusion created by turbulence in Earth's atmosphere. As Earth passes another planet, its gravitational pull slows down the other planet so that it appears to be traveling backward.

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 actually change.

For most of history, the lack of observable stellar parallax was usually interpreted to mean that stars were too far away for parallax to be measured with available technology. Earth is stationary at the center of the universe. Galileo's theories of the universe were essentially correct. stars must all lie at the same distance from Earth, on the celestial sphere.

Earth is stationary at the center of the universe.

In which direction does a quarter Moon rise? north The Moon becomes a quarter Moon only after it has risen and changed phase. west east south

East

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

It appears very near the north celestial pole.

How does Earth's varying distance from the Sun affect our seasons? It makes summer warmer in the Northern Hemisphere than in the Southern Hemisphere. It is responsible for the fact that the seasons are opposite in the Northern and Southern hemispheres. It causes the seasons to be more extreme than they would be if the Earth's distance from the Sun were always the same. It doesn't—Earth's orbital distance plays no significant role in the seasons.

It doesn't—Earth's orbital distance plays no significant role in the seasons.

What is stellar parallax? 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. It is the daily rise and set of the stars. It is the change in the set of constellations that we see at different times of year in the evening sky. 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.

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.

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? Yes, they appear as small, fuzzy patches on the other side of our galaxy. No, because there are only galaxies above and below the plane of the Milky Way. Yes, there are many other galaxies that we see inside the Milky Way. No, because the stars, gas, and dust of the Milky Way block us from seeing them, however we can see close galaxies. No, we cannot see any other galaxies from Earth.

No, because the stars, gas, and dust of the Milky Way block us from seeing them, however we can see close galaxies.

At approximately what time would a first quarter Moon rise? noon 6 A.M. midnight 9 A.M. 6 P.M.

Noon

What effect or effects would be most significant if the Moon's orbital plane were exactly the same as the ecliptic plane? Solar eclipses would be more frequent and shorter. Solar eclipses would last much longer. Solar eclipses would be rarer and longer. Solar eclipses would be much rarer. Solar eclipses would be much more frequent.

Solar eclipses would be much more frequent.

Why are lunar eclipses more commonly seen than solar eclipses? The tilt of the Moon's axis is smaller than the Earth's. The Moon goes around the Earth faster than the Earth goes around the Sun. Lunar eclipses occur at night and are easier to see. The Earth casts a bigger shadow than the Moon. The Moon is much closer to the Earth than the Sun.

The Earth casts a bigger shadow than the Moon.

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

The Moon's umbra must touch the area where you are located.

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

The Northern Hemisphere is tilted toward the Sun and receives more direct sunlight.

Which of the following statements is true? Both the Northern and Southern hemispheres receive the same amount of sunlight on the solstices. None of these. The Northern Hemisphere receives the most direct sunlight on the summer solstice. The Southern Hemisphere receives the most direct sunlight on the summer solstice. Neither hemisphere receives sunlight on the solstice

The Northern Hemisphere receives the most direct sunlight on the summer solstice.

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

The altitude of the NCP is the same as your latitude.

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

The celestial sphere is a representation of how the entire sky looks as seen from Earth.

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

The closer a star is to us, the more parallax it exhibits.

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

The closer a star is to us, the more parallax it exhibits.

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? 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. Polaris would not be our North star. The region of Earth where the Sun does not rise on the winter solstice would be larger (extending farther south) than it is now. Summers and winters would be more severe (for example, hotter and colder, respectively) than they are now.

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.

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

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.

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

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.

Which of the following never appears to exhibit retrograde motion? Mars the Sun Venus Jupiter Saturn

The sun

Which of the following best describes why we have seasons on Earth? The tilt of Earth's axis causes the northern hemisphere to be closer to the Sun than the southern hemisphere in summer, and visa versa in winter. The tilt of Earth's axis causes different portions of the Earth to receive more or less direct sunlight at different times of year. 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. 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.

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

Which of the following statements about circumpolar stars is true at all latitudes? Like all other stars, they rise in the east and set in the west. You cannot see them from the Southern Hemisphere. They make relatively small circles, traveling clockwise around the north celestial pole. They are the stars close to the north celestial pole. They always remain above your horizon.

They always remain above your horizon.

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? Your friend will see a first quarter Moon. Your friend will see a gibbous Moon.! Your friend will also see a crescent Moon. Your friend won't see the Moon tonight, because it is up only in the morning.

Your friend will also see a crescent Moon.

Which of the following correctly describes the meridian in your local sky? a half-circle extending from your horizon due north, through your zenith, to your horizon due south a half-circle extending from your horizon due east, through your zenith, to your horizon due west a half-circle extending from your horizon due east, through the north celestial pole, to your horizon due west the point directly over your head

a half-circle extending from your horizon due north, through your zenith, to your horizon due south

Which of the following best describes the modern definition of a constellation? a collection of stars that are near one another in space a region of the celestial sphere a Greek mythological figure a pattern of bright stars in the sky a group of stars that all lie at about the same distance from Earth

a region of the celestial sphere

What is a circumpolar star? a star that makes a daily circle around the celestial sphere a star that always remains above your horizon and appears to rotate around the celestial pole a star that is visible from the Arctic or Antarctic circles a star that is close to the north celestial pole a star that is close to the south celestial pole

a star that always remains above your horizon and appears to rotate around the celestial pole

Why do we see essentially the same face of the Moon at all times? because the other face points toward us only at new Moon, when we can't see the Moon because the Sun illuminates only one half at a time because the Moon's rotational and orbital periods are equal because the Moon has a nearly circular orbit around Earth because the Moon does not rotate

because the Moon's rotational and orbital periods are equal

If the Moon is setting at 6 A.M., the phase of the Moon must be waning crescent. new. full. third quarter. first quarter.

full

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

higher in the sky.

If we have a new Moon today, when we will have the next full Moon in about 2 weeks in about a month in about 6 months in about 1 week

in about 2 weeks

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

increasing the size of Earth's orbit

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

over many days or weeks, the planet moves westward relative to the stars, rather than the usual eastward relative to the stars.

During a Lunar Eclipse, if part of the full Moon passes through Earth's umbra, we will see a(n) partial solar eclipse. total lunar eclipse. penumbral lunar eclipse. partial lunar eclipse. annular eclipse.

partial lunar eclipse.

During a Lunar Eclipse, 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.

partial lunar eclipse.

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

the path the Sun appears to trace around the celestial sphere each year

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

the spring and fall equinoxes.

The point directly over your head is called the meridian. the north celestial pole. the zenith. the North Star.

the zenith.

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? first quarter third quarter new full

third quarter

If the Moon is rising at midnight, the phase of the Moon must be first quarter. third quarter. waning crescent. full. waxing crescent.

third quarter.

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

to the right of Polaris; that is, 90 degrees counterclockwise from its current position