| A | B |
|---|
| blueshift | galaxies moving quickly toward an observer appears bluer than normal |
| redshift | galaxies moving quickly away from an observer appears redder than normal |
| doppler effect | as light or sound moves toward and past an observer, the pitch changes |
| Ptolemy | early astronomer who believed the earth was at the center of the universe |
| Kepler | Early astronomer who believed all planets revolve around the sun and their orbits are elliptical |
| elliptical | oval in shape |
| constellations | patterns of stars |
| frame of reference | the viewpoint of objects - how you see the objects |
| light year | the distance light travels in a year - 5.676 trillion miles |
| Galileo | early astronomer who was one of the first people to use a telescope and observe the moon |
| Copernicus | Early astronomer who stated that the sun was the center of the universe - not a popular theory at the time |
| radio telescopes | a device that detects radio waves from deep space |
| electromagnetic spectrum | radio waves, microwaves, infrared, visible light, ultraviolet, xrays, gamma rays |
| Hubble telescope | sensitive telescope launched in space in 1990 |
| 4.6 billion years | age of the earth |
| 15-20 billion years | age of the universe |
| 5 billion years | age of our sun |
| Aristotle | supported the geocentric model |
| light | fastest thing in the universe |
| stars | have made ALL the elements in the universe |
