Across
- 4. An optical tool used to see things that are far
- 5. a unit of measurement equal to 149.6 million kilometers
- 9. when two light nuclei merge to form a single heavier nucleus
- 10. a point in space where a given mass is infinitely dense
- 11. a system of millions or billions of solar systems held together by gravity
- 12. A point where matter is infinitely dense
Down
- 1. when something moving away looks red
- 2. The study of celestial bodies, objects, space, etc.
- 3. the change in wave length relative to the motion of between a wave source and the observer
- 6. A huge cloud of dust and gas and it also acts as a nursery for new stars
- 7. a group of stars that make a well known image
- 8. a type of star that is small and has a white color to it