Across
- 2. Something that scientists have observed as always behaving in the same way (3 letters)
- 5. A person who travels in space (9 letters)
- 9. Puzzle:
- 11. A section of a rocket or spacecraft that has its own engine (5 letters)
- 12. Units of measurement for determining energy (6 letters)
Down
- 1. Thread of a particular substance that are combined to form materials (7 letters)
- 3. The height of an object above Earth's surface or sea level (8 letters)
- 4. The loads carried by spacecraft, such as passengers, cargo, or satellites (8 letters)
- 6. The amount of matter that an object contains (4 letters)
- 7. An invisible force that pulls two objects towards each other (7 letters)
- 8. A machine used to travel in space (6 letters)
- 10. The programs that run on a computer, telling it how to complete certain tasks (8 letters)