Across
- 2. The second element of the Periodic Table
- 5. A collection of stars and planets
- 6. The perceived colour 'shift' when an object moves away from you
- 7. The element on the periodic table with the symbol 'H'
- 9. The effect that describes movement through space
Down
- 1. The perceived colour 'shift' when an object moves towards you
- 3. The 'M' in the equation E=mc^2
- 4. Bright things in the night sky
- 6. Something that emits or receives soundwaves
- 8. The only thing that existed before the Big Bang