The size of a typical dorm room
The size of a typical campus building
The size of a typical campus
The size of a small city
The size of a western state (e.g.,Colorado)
It was produced in the Big Bang.
It was created by chemical reactions in interstellar space.
It was produced by nuclear fusion in stars.
It was made by our Sun.
It was made by nuclear fission of uranium and other radioactive materials.
An explosion caused by putting together two volatile chemicals
The process of splitting nuclei to produce energy
The process of turning matter into pure energy
The process of combining lightweight nuclei to make heavier nuclei
A process that only occurs in bombs
It's about 4 light-years from here to Alpha Centauri.
It will take me light-years to complete this homework assignment.
A light-year is about 10 trillion kilometers.
It will take the Voyager spacecraft about 20,000 years to travel just 1 light-year.
The Milky Way Galaxy is about 100,000 light-years in diameter.
Earth is the size of a point about 1 meter away from the Sun.
Earth is the size of a golf ball about 1 meter away from the Sun.
Earth is the size of a point about 15 meters away from the Sun.
Earth is the size of a golf ball about 15 meters away from the Sun.
Earth is the size of a marble about 25 miles away from the Sun.
Hydrogen and oxygen
Hydrogen and helium
Carbon and nitrogen
Oxygen and carbon
Nearly equal portions of all the elements
Size of a typical planet
Size of a typical star
Size of a typical galaxy
Size of Pluto's orbit
Distance to the nearest star (other than our Sun)
The length of a football field
A spiral galaxy with a disk about 100,000 light-years in diameter and containing between 100 billion and 1 trillion stars
A spiral galaxy with a disk about a billion kilometers in diameter and containing between 100 million and 1 billion stars
A spiral galaxy with a disk about 100,000 light-years in diameter and containing about 100,000 stars
A spherically shaped collection of stars including our solar system and about a dozen other solar systems, stretching about 4 light-years in diameter
A spherically shaped collection of about 1 million stars that is about 100 light-years in diameter
About half the year
About a month about a month about a month
A few hours
A few seconds
Less than a millionth of a second
Not moving at all
10 thousand years
230 thousand years
1 million years
100 million years
230 million years
It contains between 100 billion and 1 trillion stars.
Our solar system is located very close to the center of the Milky Way Galaxy.
The galaxy is about 100,000 light-years in diameter.
One rotation of the galaxy takes about 200 million years.
Counting the number of stars.
Determining the amount of gas and dust.
Studying how stars are distributed in the Milky Way.
Studying the rotation of the galaxy.
Weighing various parts of the Milky Way.
All raisins would be moving away from you at the same speed.
More distant raisins would be moving away from you faster.
More distant raisins would be moving away from you more slowly.
It depends: If you lived in a raisin near the left side of the cake, you'd see other raisins moving away from you, but they'd be coming toward you if you lived in a raisin near the right side of the cake.
It lies along the band of light we call the Milky Way.
It represents an extension of Earth's equator onto the celestial sphere.
It cuts the dome of your local sky exactly in half.
It extends from your horizon due east, through your zenith, to your horizon due west.
It extends from your horizon due north, through your zenith, to your horizon due south.
Daytime in Sydney, Australia.
Midnight in Sydney, Australia.
Midnight in Los Angeles.
Midday in Rio de Janeiro, Brazil.
It is the brightest star in the sky.
It is the star straight overhead.
It appears very near the north celestial pole.
It is the star directly on your northern horizon.
It can be used to determine your longitude on Earth.
30 degrees up, due West
On the northern horizon
The answer depends on whether it's winter or summer.
The answer depends on what time of day (or night) it is.
The Northern Hemisphere is closer to the Sun than the Southern Hemisphere.
The Northern Hemisphere is "on top" of Earth and therefore receives more sunlight.
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.
It isn't: both hemispheres have the same seasons at the same time.
Both the Northern and Southern hemispheres receive the same amount of sunlight on the equinoxes.
Both the Northern and Southern hemispheres receive the same amount of sunlight on the solstices.
The Northern Hemisphere receives the most direct sunlight on the summer solstice.
The Southern Hemisphere receives the most direct sunlight on the summer solstice.
Both A and C are true.
There are only 88 official constellations.
Some constellations can be seen from both the Northern and Southern hemispheres.
Some constellations can be seen in both the winter and summer.
It is possible to see all the constellations from Earth's equator.
Most constellations will be unrecognizable hundreds of years from now.
The Moon goes through a cycle of phases because it always has the same side facing Earth.
If you see a full Moon from North America, someone in South America would see a new moon.
The Moon's distance from Earth varies during its orbit.
The Moon is visible only at night.
The side of the Moon facing away from Earth is in perpetual darkness.