Across
- 3. The path of an object that is moving around a second object or point
- 5. Turning of a body on its axis
- 7. The change in frequency of a wave (or other periodic event) for an observer moving relative to its source
- 11. Unit of distance, equal to the distance of the Earth from the Sun, about 150 million kilometers
- 12. The cutting off of light from one celestial body by another
- 14. A small body of ice and dust in orbit around the Sun
- 15. A large group of stars
Down
- 1. The luminous phenomenon seen when a meteoroid enters the atmosphere
- 2. An extremely distant, and thus old, celestial object whose power output is several thousand times that of our entire galaxy
- 4. All the matter and energy out there
- 6. A thin flow of energetic and gas charged particles that stream from the Sun
- 8. The distance light travels in a vacuum in one year
- 9. Movement of a planet around the Sun; more generally, orbital motion about a point
- 10. The shape an object takes in orbit
- 13. The sun's outer atmosphere