Space

4. The first British astronaut (5,7)
8. The most recent British man to go in to space (3,5)
9. A natural satellite that orbits a planet (4)
10. Smallest planet, closest to the sun (7)
14. The star at the centre of our solar system (3)
15. A vehicle used to transport humans, technology or other things in to space (6)
16. The planet named after the Roman God of the sea (7)
18. A person trained to serve as a crew member of a space craft (9)
20. An instrument used to view stars and other objects in space from Earth (9)

1. Small rocky objects that orbit the sun (9)
2. gravitationally bound system of stars, gas, dust, and dark matter, and a chocolate bar (6)
3. A region of spacetime where gravity is so strong that nothing can escape from it. (5,4)
5. The third closest planet to the sun (5)
6. The biggest planet (7)
7. Acronym for the National Aeronautics and Space Administration, the American space agency (4)
11. A group of stars which forms an outline or pattern, usually of an animal, person or creature (13)
12. Astronomical objects made of plasma which hold themselves together with the force of their own gravity (4)
13. City in the Midlands which has the National Space Centre (9)
17. The planet known for its large, icy rings (6)
19. The number of moons that Mars has (3)