Across
- 2. The regularly repeated elliptical course of a celestial object or spacecraft about a star or planet
- 5. A celestial body moving in an elliptical orbit round a star
- 6. The force that attracts a body towards the center of the earth, or towards any other physical body having mass
- 8. A space entirely devoid of matter
- 10. A strong gravitational force that light can not escape from
Down
- 1. A fixed luminous point in the night sky which is a large, remote incandescent body like the sun
- 3. A cylindrical projectile that can be propelled to a great height or distance
- 4. All existing matter and space considered as a whole; the cosmos
- 7. A system of millions or billions of stars, together with gas and dust, held together by gravitational attraction
- 9. The natural satellite of the earth, visible by reflected light from the sun