Across
- 4. The daily disappearance of the sun below the horizon.
- 5. The region beyond the earth’s atmosphere containing the other planets of the solar system, stars, galaxies, etc.
- 7. The force of attraction by which terrestrial bodies tend to fall toward the center of the Earth.
- 8. The planet on which human beings live.
Down
- 1. Any of the eight celestial bodies revolving around the Sun.
- 2. The people who serve on a spacecraft.
- 3. The rise of the sun above the horizon in the morning.
- 4. A vehicle designed for travel in space.
- 6. A person trained for travelling in space.