ASTR CHAPTER 2 Q&A'S

What do astronomers mean by a constellation? -A constellation is any random grouping of stars in the sky -.A constellation is a group of stars that are all located in about the same place in space. -A constellation is a region in the sky as seen from Earth. -A constellation is a group of stars related through an ancient story.

-A constellation is a region in the sky as seen from Earth.

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

When we see Saturn going through a period of apparent retrograde motion, it means -Saturn and Earth must be on opposite sides of the Sun. -Saturn is temporarily moving backward in its orbit of the Sun. -Earth is passing Saturn in its orbit, with both planets on the same side of the Sun.

-Earth is passing Saturn in its orbit, with both planets on the same side of the Sun.

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.) -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. -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. -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. -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.

-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.

Polaris is 10 degrees above your horizon. Where are you? -Latitude 80 degrees north -Latitude 80 degrees south -Latitude 10 degrees south -Latitude 10 degrees north

-Latitude 10 degrees north

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.

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 representation of how the entire sky looks as seen from Earth. -It represents a belief in an Earth-centered universe, and hence is no longer considered to have any use. -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.

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

Which of the following statements about the celestial sphere is not true? -The Earth is placed at the center of the celestial sphere. -The celestial sphere is another name for our universe. -When we look in the sky, the stars all appear to be located on the celestial sphere. -The celestial sphere does not exist physically.

-The celestial sphere is another name for our universe.

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

-The patchy band of light that outlines the plane of the Milky Way Galaxy as seen from Earth.

What is the ecliptic? -The path the Sun appears to trace around the celestial sphere each year -The path traced by the Moon's shadow on Earth during a solar eclipse -The Sun's daily path from east to west in our sky -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

We see two stars separated by one degree on the celestial sphere. What can we infer about these stars? -They were born about the same time. -They are very close together in space. -They have similar luminosities. -They rise and set at about the same time.

-They rise and set at about the same time.

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

-We could not see it at all.

As Earth goes around the Sun each year, Earth's rotation axis in the North points -in the direction of the celestial pole, near Polaris, throughout the year. -tipped toward the galactic center, 23-1/2 degrees. -in a direction that traces a cone of radius 23-1/2 degrees, crossing through Polaris and Vega. -tipped toward the Sun, 23-1/2 degrees.

-in the direction of the celestial pole, near Polaris, throughout the year.

If the Sun rises precisely due east: -you must be located at Earth's equator. -it must be the day of either the spring or fall equinox. -it must be the day of the summer solstice.

-it must be the day of either the spring or fall equinox.

The North Celestial Pole is 35∘∘ above your northern horizon. This tells you that you are at: -latitude 35∘∘ N. -longitude 35∘∘ E. -latitude 35∘∘ S.

-latitude 35∘∘ N.

Two stars that are in the same constellation: -must both be part of the same cluster of stars in space. -must both have been discovered at about the same time. -may actually be very far away from each other.

-may actually be very far away from each other.

In winter, Earth's axis points toward the star Polaris. In spring: -the axis also points toward Polaris. -the axis points toward Vega. -the axis points toward the Sun.

-the axis also points toward Polaris.

What is the ecliptic? -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 daily path from east to west in our sky -the path traced by the Moon's shadow on Earth during a solar eclipse

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

Beijing and Philadelphia have about the same latitude but very different longitudes. Therefore, tonight's night sky in these two places: -will look about the same. -will have completely different sets of constellations. -will have partially different sets of constellations.

-will look about the same.

If Earth's rotation slowed down so that it completed exactly one rotation about its axis in 100 hours, what would be the typical time interval between sunrise and sunset? 100 hours 24 hours 50 hours 25 hours

50 hours

What do astronomers mean by a constellation? A constellation is a group of stars that are all located in about the same place in space. A constellation is any random grouping of stars in the sky. A constellation is a region in the sky as seen from Earth. A constellation is a group of stars related through an ancient story.

A constellation is a region in the sky as seen from Earth.

Which of the following celestial objects do not rise in the east and set in the west? (Assume that all of these objects are visible from your location on Earth, and that none of them are circumpolar.) the Moon stars the Sun galaxies All of these objects rise in the east and set in the west.

All of these objects rise in the east and set in the west.

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 1 week In about 6 months

In about 2 weeks

What is stellar parallax? -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 daily rise and set of the stars. -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 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.

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 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 -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.

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

If you are located in the Northern Hemisphere, which of the following correctly describes a relationship between the sky and your location? The altitude of the north celestial pole equals your longitude. The altitude of the north celestial pole equals your latitude. The altitude of the celestial equator equals your latitude. The longitude of the north celestial pole is circumpolar, and therefore crosses your zenith at the meridian.

The altitude of the north celestial pole equals your latitude.

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

The angular distance between those two bright stars in the sky is about 2 meters.

What is the saros cycle? The roughly 18-year cycle over which the pattern of eclipses repeats The annual cycle of the seasons The roughly one-month cycle of lunar phases in the sky The 26,000-year cycle of the Earth's precession

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

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. -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.

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

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? To the left of Polaris; that is, 90 degrees clockwise from its current position Directly above Polaris Still in the same place, below Polaris To the right of Polaris; that is, 90 degrees counterclockwise from its current position

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

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

a couple thousand

We cannot see a new moon in our sky because _________. it is above the horizon during the daytime a new moon is quite near the Sun in the sky it is obscured by Earth's shadow no sunlight is illuminating the Moon

a new moon is quite near the Sun in the sky

About how many stars are visible to the naked eye on a clear, dark night away from city lights? a few hundred billion a few dozen approximately two thousand several million

approximately two thousand

Stars that are visible in the local sky on any clear night of the year, at any time of the night, are called _________. bright circumpolar seasonal celestial

circumpolar

If a star's distance from Earth increased, its parallax shift would __________. SHOW HINT increase decrease not change

decrease

Lunar eclipses can occur only when the phase of the Moon is _________. third quarter new full first quarter

full

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

higher in the sky

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

latitude 40 degrees south

We describe a location on Earth's surface by stating its _________. latitude and longitude latitude and direction altitude and direction (or azimuth) meridian and longitude

latitude and longitude

An angle of 1 arcsecond is _________. about the width of your fist held at arm's length slightly more than the width of a basketball held at arm's length about the width of a finger held at arm's length less than the thickness of a human hair held at arm's length

less than the thickness of a human hair held at arm's length

The fact that we always see the same face of the Moon tells us that the Moon looks the same on both sides. rotates with the same period that it orbits Earth. does not rotate.

rotates with the same period that it orbits Earth.

The Moon always shows nearly the same face to Earth because ________. the Moon rotates once in the same amount of time that it takes Earth to orbit the Sun once sunlight always hits the same face of the Moon the Moon rotates once in the same amount of time that it takes the Moon to orbit Earth once the Moon does not rotate

the Moon rotates once in the same amount of time that it takes the Moon to orbit Earth once

If there is going to be a total lunar eclipse tonight, then you know that: the Moon's phase is full. the Moon's phase is new. the Moon is unusually close to Earth.

the Moon's phase is full.

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

the zenith

A week after full moon, the Moon's phase is: first quarter. third quarter. new.

third quarter.

When it is summer in Australia, the season in the United States is winter. summer. spring.

winter