Across
- 3. a system of millions or billions of stars
- 4. artificial body orbit a planet
- 8. a metric of length equal to 1,000 meters
- 9. describes how long a wave is
- 11. the planet we live in
- 13. event with potential to cause harm
- 14. type of astrophotography
- 17. the classification of living organisms
- 18. small rocky body
- 19. a body of ice and dust
- 20. used to measure the distance between planets
- 21. natural satellite of earth
- 22. massive self-luminous celestial body of gas
- 23. a tool astronomers use to see faraway
- 24. used to measure the distance between earth and sun
- 25. the rate of when something occurs
Down
- 1. emission of energy in space
- 2. small planet
- 5. a celestial body moving in a orbit of a star
- 6. collection of planets that orbit a star
- 7. a cloud of gas and dust
- 10. the force that pull objects together
- 12. includes all of spaces
- 15. the range of wavelengths or frequencies
- 16. a variation that transfers energy