Solve these clues to fill the grid.
- Natural satellite that orbits the Earth
- 3 Across
- Any vehicle self-propelled by a ___ engine
- 4 Across
- Any vehicle self-propelled by a ___ engine (plural)
- 8 Across
- The vast area beyond Earth's atmosphere
- 9 Across
- A person trained to travel in a spacecraft
- 11 Across
- Greek god of light
- 12 Across
- Someone who is the first to think of or make something
- 1 Down
- A bowl-shaped geological formation at the top of a volcano (plural)
- 2 Down
- A former gold coin in the United States worth 10 dollars
- 5 Down
- Study of what happened in the past
- 6 Down
- A North American river
- 7 Down
- The planet we live on
- 10 Down