Across
- 1. The distance light travels in a year
- 6. The telescope the helped us discover there could be 100 billion other galaxies in the universe
- 8. the whole cosmic system of matter and energy of which Earth, and therefore the human race, is a part
Down
- 2. A big ball of gas filled with many stars, dust, and dark matter
- 3. The Galaxy where earth and the sun are located
- 4. The heart of our solar system
- 5. the branch of science which deals with celestial objects, space, and the physical universe as a whole.
- 7. An illuminated ball of fiery gas