astronomy 2

At latitude 50 degrees North, the celestial equator crosses the meridian at altitude:

40 degrees in the South

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 a region in the sky as seen from Earth. A constellation is any random grouping of stars in the sky. A constellation is a group of stars related through an ancient story.

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

You observe a full Moon rising at sunset. What will you see at midnight? A full moon high in the sky A third-quarter moon A waning gibbous moon A first-quarter moon

A full moon high in the sky

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

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

Which of the following is not true about a scientific theory?

A theory is essentially an educated guess.

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

Earth is catching up with and passing by Mars in their respective orbits

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

Earth is stationary at the center of the universe

Earth is closer to the Sun in January than in July. Therefore, in accord with Kepler's second law:

Earth travels faster in its orbit around the Sun in January than in July.

Each choice 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 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 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 month. Earth's orbit defines a year. Earth's cycle of axis precession takes 26,000 years.

If we have a new moon today, when we will have the next full moon? In about two weeks In about a month In about one week In about six months

In about two weeks

How does Earth's varying distance from the Sun affect our seasons? It doesn't; Earth's orbital distance plays no significant role in the seasons. 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 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 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 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.

Which of the following was not a major advantage of Copernicus's Sun-centered model over the Ptolemaic model?

It made significantly better predictions of planetary positions in our sky

According to Kepler's third law:

Jupiter orbits the Sun at a faster speed than Saturn.

Two stars that are in the same constellation:

May actually be very far from each other

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

A newly discovered planet orbits a distant star with the same mass as the Sun at an average distance of 106 million kilometers. Its orbital eccentricity is 0.4. Part A: Find the planet's orbital period. Part B: Find the planets nearest orbital distance from its star Part C: Find the planet's farthest orbital distance from its star

Part A: 7.16 months Part B: 0.43 AU Part C: 0.99 AU

Part A: The dwarf planet Eris orbits the Sun every 557 years. What its average distance (semi major axis) from the Sun? Part B: How does its average distance compare to that of Pluto?

Part A: Eris's semi major axis = 67.7 AU Part B: aEris/aPluto = 1.72

Halley's comet orbits the Sun every 76.0 years and has an orbital eccentricity of 0.97 . Part A: Find its semi major axis distance. Part B: Find its perihelion distance. Part C: Find its aphelion distance. Part D: Does Halley's comet spend most of its time near its perihelion distance, its aphelion distance, or halfway between?

Part A: Semi major axis distance = 17.9 AU Part B: 0.537 AU Part C: 35.3 AU Part D: Near its aphelion distance

Part A: The Shadow cast by a simple stick or obelisk allowed ancient people to: Part B: Why wasn't the sun-centered model of Copernicus immediately adopted after he proposed it? Part C: An original observation of Galileo's that helped to overturn the ancient Earth-centered model was: Part D: Which of the following are the three key hallmarks of science? (3)

Part A: Tell the time of day Part B: It was not noticeably more accurate than the old Ptolemaic model Part C: The phases of Venus Part D: 1) science progresses through the creation and testing of models of nature that explain the observations as simply as possible. 2) models must make testable predictions that will force us to revise or abandon the model if they do not agree with observations. 3) modern science seeks explanations for observed phenomena that rely solely on natural causes

Part A: Choose the correct description of the path of the Sun at a latitude of 40 degrees North for the March and September equinoxes. Part B: Choose the correct description of the path of the Sun at a latitude of 40 degrees North for the summer (June) solstice. Part C: Choose the correct description of the path of the Sun at a latitude of 40 degrees North for the winter (December) solstice

Part A: The sun rises due east, reaches an altitude of 50 degrees South on the meridian, and sets due west Part B: On the June solstice, the Sun rises more than 23.5 degrees north of due east, reaches an altitude of 73.5 degrees on the meridian in the south, and sets more than 23.5 degrees north of due west. Part C: On the December solstice, the Sun rises more than 23.5 degrees south of due east, reaches an altitude of 26.5 degrees on the meridian in the south, and sets more than 23.5 south of due west.

In winter, Earth's axis points toward the star Polaris. In spring, the axis points toward...

Polaris

What does the fact that we always see the same face of the Moon tells us about?

The Moon rotates with the same period that it orbits Earth

Summarize the development of the Greek geocentric model through Ptolemy. How did the Ptolemaic model account for apparent retrograde motion?

The Ptolemaic model was able to explain retrograde motion by having the planets move backward on their circular orbits on which they went around Earth

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 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. The altitude of the celestial equator equals your latitude.

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 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. 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.

What is the celestial sphere? 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 model that shows the true locations in space of the Sun and a few thousand of the nearest stars. 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 the celestial sphere is not true? When we look in the sky, the stars all appear to be located on the celestial sphere. The Earth is placed at the center of the celestial sphere. The celestial sphere does not exist physically. The celestial sphere is another name for our universe.

The celestial sphere is another name for our universe.

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

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.

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

The orbital plane of the Moon is tilted slightly (by about 5 degrees) to the ecliptic plane.

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

What is the ecliptic? 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 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

In the Greek geocentric model, the retrograde motion of a planet occurs when:

The planet actually goes backward in its orbit around Earth

What is the saros cycle? 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 The annual cycle of the seasons

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

Beijing and Philly have about the same latitude but different longitudes. What can be said about the tonight's night sky in these two places?

The sky will look about the same.

Last night I saw Jupiter right in the middle of the Big Dipper. (Hint: Is the Big Dipper part of the Zodiac?) Choose the correct explanation why the statement makes sense (or is clearly true) or does not make sense (or is clearly false)

The statement does NOT make sense because Jupiter, like all the planets, is always found very close to the ecliptic in the sky. The ecliptic passes through the constellations of the zodiac, so Jupiter can only appear to be in one of the zodiac constellations - and the Big Dipper is not part of the zodiac.

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

I live in the United States, and during my first trip to Argentina I saw many constellations that I'd never seen before. Choose the correct explanation why the statement makes sense (or is clearly true) or does not make sense (or is clearly false)

This statement makes sense, because the constellations visible in the sky depend on latitude. Since Argentina is in the Southern Hemisphere, the constellations visible there include many that are not visible from the U.S.

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

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

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 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 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 would be in the constellation Sagittarius instead of Andromeda.

We could not see it at all.

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

Winter

The South Celestial pole is 40 degrees above your Southern Horizon. What does it tell you?

You're at latitude 40 degrees South

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 also see a crescent moon. Your friend will see a gibbous 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.

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 several million a couple thousand

a couple thousand

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

a new moon is quite near the Sun in the sky

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

a.

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 40 degrees north latitude 50 degrees south

atitude 40 degrees south

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 getting closer together. b. Earth is catching up with and passing by Mars in their respective orbits. c. Mars is moving around the Sun in the opposite direction from which Earth is moving around the Sun. d. Earth and Mars are on opposite sides of the Sun.

b.

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. Earth is stationary at the center of the universe c. Galileo's theories of the universe were essentially correct d. stars were too far away for parallax to be measured with available technology

b.

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. the Earth would not have seasons b. the four seasons would each be twice as long as they are now c. the cycle of precession would take 13,000 years instead of 26,000 years d. stars would take twice as long to rise and set

b.

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 also see a crescent moon. c. Your friend will see a gibbous moon. d. Your friend won't see the Moon tonight, because it is up only in the morning.

b.

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 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.

b.

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

b.

You observe a full moon rising at sunset. What will you see at midnight? a. A waning gibbous moon b. A full moon high in the sky c. A first quarter moon d. A third quarter moon

b.

It's 6 am and the Moon is at its highest point in your sky (crossing the meridian). What is the Moon's phase? a. new b. full c. third quarter d. first quarter

c.

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 Arecibo radio telescope in Puerto Rico b. the Hubble Space Telescope (which orbits Earth) c. the Galileo spacecraft that orbited Jupiter in the 1990s d. the Keck telescope on Mauna Kea, Hawaii

c.

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

c.

At the North Pole on the summer solstice, the Sun:

circles the horizon at altitude 23 1/2 degrees

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

circumpolar

Tycho Brahe's contribution to astronomy included:

collecting data that enabled Kepler to discover the laws of planetary motion.

All the following statements are true. Which one explains the reason that there is not a solar eclipse at every new moon? a. The Moon is only about 1/4 as large as Earth in diameter. 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 orbital plane of the Moon is tilted slightly (by about 5 degrees) to the ecliptic plane.

d.

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

d.

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

d.

Suppose it is full moon. What phase of Earth would someone on the Moon see at this time? a. full Earth b. first quarter Earth c. Earth does not go through phases as seen from the Moon. d. new Earth

d.

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. Still in the same place, below Polaris b. Directly above 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

d.

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 50 degrees south b. latitude 40 degrees north c. longitude 40 degrees d. latitude 40 degrees south

d.

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

d.

A star's path through your sky depends on your latitude and the star's:

declination

A star that is located 30 degrees north of the celestial equator has:

declination = 30 degrees

Lunar eclipses can occur only during a _________. full moon new moon third-quarter moon first-quarter moon

full moon

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

higher in the sky

When we say that a planet has a highly eccentric orbit, we mean that:

in some parts of its orbit it is much closer to the Sun than in other parts.

If the Sun rises precisely due east,

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

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

latitude and longitude

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

Galileo's contribution to astronomy included:

making observations and conducting experiments that dispelled scientific objections to the Sun-centered model.

Suppose it is full Moon. What phase of Earth would someone on the Moon see at this time? full Earth Earth does not go through phases as seen from the Moon. new Earth first-quarter Earth

new Earth

In any particular place on Earth, certain constellations are visible in the evening only at certain times of the year because _________. during some times of year, some constellations drop below the southern horizon some constellations are circumpolar our evening view of space depends on where Earth is located in its orbit around the Sun on any particular night, we can only see stars that are directly opposite (180 degrees away from) the Sun in the sky

our evening view of space depends on where Earth is located in its orbit around the Sun

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

the Galileo spacecraft that orbited Jupiter in the 1990s

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 December solstice the March and September equinoxes the June solstice

the March and September equinoxes

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

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

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

the four seasons would each be twice as long as they are now

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

the zenith

A week after full moon, the Moon's phase is:

third quarter

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