Across
- 4. The _______ effect is the apparent change in frequency of a wave in relation to an observer moving relative to the wave source.
- 6. When the star moves away from us, its spectrum looks slightly redder. This is called ___.
- 8. ________'s Law states that the universe is expanding and that galaxies are moving away from each other.
- 10. When a main sequence star begins to run out of hydrogen fuel, the star becomes a ______
- 12. the distance from the peak of one wave to the peak of the next
- 13. Kepler's _________ Law stated that the planet revolves around the Sun in an elliptical path, with the Sun occupying one of the foci of the ellipse.
- 18. ________'s Law describes how the earth's orbit changes.
- 19. counts the number of waves that pass by a given point over a given period of time
- 21. When a star explodes and dies, the explosion is called a _________
Down
- 1. If a siren is coming towards you, the wavelengths would be ________ than when it is moving away.
- 2. The type of galaxy that has no known shape and contains large amounts of new stars.
- 3. Stars begin their lives as clouds of dust and gas called a__
- 5. The word to describe the path a planet travels around the sun
- 7. The type of galaxy that is football shaped, makes up 60% of the galaxies in the universe, and has little to no star formation
- 9. The contracting cloud that is formed after the nebula
- 11. Stars and gases are held together by
- 14. The type of galaxy that contains very old and new stars.
- 15. A collection of billions of stars
- 16. Kepler's _________ Law states that the closer a planet is to the sun the faster it will orbit.
- 17. ________ and Helium are the two elements that are involved in nuclear fusion
- 20. Nuclear _____ is the process that happens in the core of the stars where the nuclei of the the atoms join together