Mission to Mars

5. A moon, planet or machine that orbits a planet or star.
8. A regular oval shape. (The shape of the orbit of objects in space).
10. The study of space including stars, planets, comets and galaxies
11. A non-contact force that attracts objects to each other
12. Any form of water that falls to the Earth’s surface, such as rain, snow, sleet or hail
15. A change in state from a liquid to a gas.
17. The imaginary line through the centre of the Earth between the South and North Poles
18. A change in state from a gas to a liquid (can occur when a gas comes into contact with a cold surface).
21. To obscure or block out (usually refers to the moon or sun being blocked out)

1. The amount of matter in an object (measured in kg or g)
2. Moving in an orbit around a celestial body
3. Velocity The steady speed of a falling object, reached when the upward push of air resistance is balanced by the downward pull of gravity.
4. A spacecraft sent out to collect science information
6. The solid, rocky part of the earth.
7. A group of stars forming a recognisable pattern (traditionally named after a mythological figure)
9. pollution The brightening of the sky by street lights and other human made sources that makes it hard to observe the stars and planets.
13. The gaseous part of the Earth
14. Turning around on an axis.
16. A celestial body moving in an elliptical orbit around a star.
19. The area around an object where a force acts (eg gravitational field, electrostatic field or magnetic field)
20. The force of gravity pulling on a mass (measured in Newtons)
22. The closest star to Earth.