Question | Answer |
What did people around the world connect to the patterns they saw in the sky? | stories about imaginary beings |
What has greatly increased out knowledge about the universe? | new tools and scientific theories |
What causes objects in space to be grouped together in difference ways? | Gravity |
What is Earth's diameter? | 13,000 km (8,000 miles) |
What is an orbit? | Path of an object in space as it moves around another object because of gravity |
What is the solar system? | the sun, planets, and various smaller bodies |
The only star in our solar system | Sun |
What galaxy is our solar system a part of? | Milky Way |
What is a galaxy? | Millions of stars held together by their own gravity. |
Why does our galaxy appear to us as a hazy band of light? | because most of the stars are so far away |
What is the universe? | Everything - space and all matter and energy in it |
What is a constellation? | Group of stars that form a pattern in the sky |
What relationship exists among the stars in a constellation? | They often appear to be grouped together when viewed from Earth but are actually far apart from one another |
Why can't you see all of the constellations at once? | Earth blocks half of space from your view |
What star does the North Pole point to? | North Star (or Polaris) - Directly over your head |
What can you use Polaris to figure out? | Directions or location |
What can't you see a star's movement? | Because you're so far away |
What does the Greek word for "planet" mean? | Wanderer |
Why is it easy to see the movements of Mars and Venus? | The two closest to the Earth |
What led early astronomers to believe that Earth was at the center of the universe? | Because it appears that the sky was moving around Earth |
What did astronomers eventually discover? | Earth and other planets orbit the sun |
How many stars are in the entire universe? | More than we can count |
The rotation of Earth makes constellations __ | Appear to change positions |
Polaris seems to stay in the same place because __ | It is straight above the North Pole |
Other stars near the North Pole seem to __ | move in a circle around Polaris |
earth, galaxy, solar system, universe
What is the correct order from largest to smallest? | Universe, galaxy, solar system Earth |
The Milky Way is one of about __ | 100 billion galaxies |
What have astronomers determined to be found throughout the universe by looking at the spectra of light from stars and galaxies? | The same elements are found throughout the universe and the same physical forces and processes are everywhere. |
What is the closest galaxy to us? | Andromeda Galaxy |
How long does it take the light from the galaxy closest to us take to reach the Earth? | 2 million years |
Why can astronomers learn about the past by looking at distant galaxies? | They can see how the universe developed over the past. |
A change in the observed wavelength or frequency of a wave that occurs when the source of the wave or the observer is moving. | Doppler Effect |
The Doppler Effect occurs with __ as well as __. | light, sound |
Light from a galaxy moving toward Earth will have a __ shift in the spectrum. | blue |
Light from a galaxy moving away from Earth will have a __ shift in the spectrum. | red |
In what way are galaxies moving? | the universe is expanding which moves the galaxies apart |
How are galaxies moving in relation to each other? | the father away they are the faster they are moving |
What did astronomers conclude about all of the matter in the universe? | the universe itself is expanding |
The moment in time when the universe started to expand out of an extremely hot, dense state | the Big Bang |
When did the Big Bang occur? | 14 billion years ago |
What is one important source of evidence for the Big Bang? | microwave radiation |
What happened to the matter and energy as the universe rapidly expanded? | It went through a series of changes |
What is one way that scientists are learning about the development of the universe? | Performing experiments in particle accelerators |
What do these huge machines do? | expose matter to extreme conditions |
When did the earliest stages of the universe's development occur? | tiny fraction of a second |
How long did it take for the first elements to form? | 300,000 years |
When did stars, planets, and galaxies begin to appear? | within the next billion years |