Astronomy final

Astronomy final

Sizes of universe- largest to smallest
The universe, the local supercluster, the local group, the Milky Way Galaxy, our solar system, the sun, Jupiter, earth
Distances from longest to shortest
The distance from the Milky Way Galaxy to the Andromeda Galaxy,
The distance from the sun to the center of the Milky Way Galaxy,
The distance from earth to alpha centauri,
One light year,
The distance across our solar system (Neptune),
One astronomical unit and the avg distance from earth to the sun.
Galaxies farthest to nearest from earth
Star on far side of Andromeda galaxy,
Star on near side of Andromeda Galaxy,
Star on far side of Milky Way galaxy,
Star near center of Milky Way galaxy,
Orion Nebula,
Alpha Centauri,
Pluto,
The sun
Longest time it would take to for light to reach earth- longest to shortest
Star on far side of Andromeda galaxy,
Star on near side of Andromeda galaxy,
Star on far side of Milky Way galaxy,
Star on near side of Milky Way galaxy,
Orion Nebula,
Alpha Centauri,
Pluto,
The Sun
How much they have aged since they admitted light we can see today from aged the most to aged the least
Star on far side of Andromeda galaxy,
Star on near side of Andromeda galaxy,
Star on far side of Milky Way galaxy,
Star on near side of Milky Way galaxy,
Orion Nebula,
Alpha Centauri,
Pluto,
The Sun
What events make up the earth from longest to most recent
The Big Bang theory and the universe begins to expand,
Elements such as carbon and oxygen exist,
Nuclear fusion beings in the sun,
Earliest life on earth,
Dinosaurs go extinct,
Earliest humans.
According to current scientific estimates, when did the Big Bang occur?
About 14 billion years ago
On the cosmic calendar, which compresses the history of the universe into a single year, about when did earth form.
In early September
On the cosmic calendar, which compresses the history of the universe into a single year, about when did life arise on earth.
In September
On the cosmic calendar, which compresses the history of the universe into a single year, about when did early humans first walk on earth?
Just a few hours before midnight on December 31
Which of the following statements best describes what astronomers mean when they say that the universe is expanding?
The avg distance between galaxies is increasing with time
Which of the following correctly lists our “cosmic address” from small to large?
Earth, solar system, Milky Way galaxy, local group, local supercluster, universe.
When we say the universe is expanding, we mean that.
The avg distance between galaxies is growing with time
If stars existed but galaxies did not
We would not exist because we are made of material that required recycling in galaxies
Could we see a galaxy that is 20 billion light years away.
No, because it would be beyond the bounds of our observable universe
An astronomical unit is:
Earth’s avg distance from the sun
The fact the nearly all galaxies are moving away from us, with more distant ones moving faster, helped us to conclude that
The universe is expanding
Define astronomical unit
The avg distance between earth and the sun, which is about 150 million kilometers
Define light year
The distance that light travels in 1 year, which is about 9.46 trillion kilometers
When we look at an object that is 1000 light years away we see it…..
As it was 1000 years ago
Suppose we look at two distant galaxies: galaxy 1 is twice as far away as galaxy 2. In that case…
We are seeing galaxy 1 as it looked at an earlier time in the history of the universe than galaxy 2
Could we see a galaxy that is 20 billion light years away? (Assume that we mean a “look book time” of 20 billion years.)
No, because it would be beyond the bounds of our observable universe.
Suppose we make a scale model of our solar system, with the sun size of a grapefruit. Which of the following best describes what the planets would look like?
The planets are all much smaller than the sun. Four planets are within about 20 meters of the sun, while the rest planets are spread much farther apart
If you could count stars at a rate of about one per second, how long would it take to count all the stars in the Milky Way galaxy
Several thousand years
The total number stars of the observable universe is about….
The same as the number of grains of sand on all beaches on earth
Using the ideas discussed in your textbook, in what sense are we “star stuff”?
Nearly every atom from which we are made was once inside of a star
How are galaxies important to our existence?
Galaxies recycle material from one generation of stars to the next, and without this recycling we could not exist.
If we imagine the history of the universe compressed into one year, dinosaurs became extinct….
Yesterday morning
Relative to the age of the universe, how old is our solar system?
It is about 1/3 of the age of the universe
How do the speeds at which we are moving with earth’s rotation and orbit compare to the speeds of more familiar objects
Earths rotation carries most people around the axis faster than a commercial jet travels, and earths orbit carries us around the Sun faster than the space shuttle orbits earth
Why do the patterns of the stars in our sky look the same from year to year
Because the stars in the constellations are so far away
Where is our solar system located within the Milky Way galaxy
Roughly halfway between the center and the edge of the visible disk of the galaxy
Astronomers infer that the universe is expanding because distant galaxies all appear to…
Be moving away from us, with more distant ones moving faster
Which statements about motion are true……and not true……
Your speed of rotation around earths axis is faster if you live near the equator than if you live near the North Pole, some stars in the Milky Way galaxy are moving toward us and others are moving away from us, except for a few nearby galaxies, all other galaxies are moving away from us
……

The mysterious dark matter is the fastest moving material in the universe

When did humans learn that the earth is not the center of the universe?
Within the past 500 years
Which planet would have seasons most like earth?
Mars
Which of the following planets should have the most extreme seasons?
Uranus
Which planet has essentially no seasons at all?
Jupiter
Which statement best describes how variation in the earth-sun distance affects the season?
The variation in the earth-sun distance over the course of each year has virtually no effect on the season.
What is the cause of seasons?
The tilt of earths axis causes different portions of the earth to receive more or less direct sunlight at different times of year.
Instead of being inclined to earths orbit around the sun, the moons orbit was in the same plane as earths orbit around the sun..approx how many solar eclipses would occur each year
12
What is the actual number of solar eclipses that occur each year is approx.
2
What conditions must exist for a so,ar eclipse to occur?
Phase of the moon must be new and the moon must be passing through earth’s orbital plane.
What conditions must exist for a lunar eclipse to occur?
Phase of the moon must be full and the moon must be passing through earths orbital plane.
Two stars that are in the same constellation
May actually be very far away from each other.
The north celestial pole is 35 degrees above your northern horizon. This tells you that:
You are at latitude 35 degrees north
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
How many arc minutes are una full circle?
21,600 arcminutes
How many arcseconds are in a full circle?
1,296,000 arcseconds
The moons angular size is about 1/2 degree. What is this in arcminutes?
30 arcminutes
What is the moons angular size in arcseconds?
1800 arcseconds
In winter, earths axis points toward the star Polaris. In spring…
The axis also points toward Polaris
If the sun rises precisely due east
It must be the day of either the spring or fall equinox
A week after full moon, the moons phase is
Third quarter
The fact the we always see the same face of the moon tells us that
The moons rotation period is the same as it’s orbital period.
When we see Saturn going through a period of apparent retrograde motion, it means
Earth is passing Saturn in its orbit, with both planets on the same side of the sun.
When it is summer in Australia, the season in the United States is
Winter
Which of the following statements about the celestial sphere is NOT true?
The “celestial sphere” is another name for our universe.

True
The celestial sphere does not exist physically,
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 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?
We could not see it all.
An angle of 1 arcseconds is…
Less than the thickness of a human hair held at arm’s length
When traveling north from the US into Canada, you’ll see the North Star (Polaris) getting..
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
Suppose you are facing north and you see the Big Dipper close to the 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 counter clockwise fro it’s current position
In any particular place on earth, certain constellations are visible in the evening only at certain times of the year because….
Our evening view of space depends on where earth is located in its orbit around the sun
The suns path, as viewed from the equator, is highest in the sky on….
The spring and fall equinoxes
Suppose earths axis tilt was significantly greater than its current 23.5 degrees, but earths rotation 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.

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

If our year were twice as long (that is, if earth took twice as many days to complete each orbit around the sun), but earths rotation period and axis tilt were unchanged, then…
The four seasons would each be twice as long as they are now
How does earths varying distance from the sun affect our seasons.
It doesn’t– earths orbital distance plays no significant role in the seasons.
Suppose you live in the US and you see a crescent moon in your evening sky tonight. What will a friend in South America see tonight?
Your friend will also see a crescent moon.
Suppose it is full moon. What phase of earth would someone on the moon see at this time?
New earth
It’s 6am and the moon is at its highest point in your sky (crossing the meridian). What is the moons phase?
Third quarter
You observe a full moon rising at sunset. What will you see at midnight?
A full moon high in the sky
All of the following statements are true. Which one explains the reason that there is not a solar eclipse at every new moon?
The orbital plane of the moon is tilted slightly (by about 5 degrees) to the ecliptic plane.
For most of history, the lack of observable stellar parallax was interpreted to mean that….
Earth is stationary at the center of the universe