Across
- 1. A region of space having such a strong gravitational effect that no light can escape. (5,4)
- 6. Planet closest to the sun.
- 7. A self-luminous object that shines through the release of energy produced by nuclear reactions at its core.
- 8. Largest moon in our Solar System.
- 9. First man on the moon (last name).
- 10. The physical force attracting two bodies.
Down
- 2. Person trained to travel in a spaceship.
- 3. The sixth planet from the sun in the solar system, circled by a system of broad flat rings.
- 4. A regularly repeated elliptical course around a celestial body, such as the sun.
- 5. Largest planet in the Milky Way.