Space

2. Shape of the Moon from the Earth when it is in different positions reflecting different amounts of light from the sun.
7. Planets that orbit a star outside of our Solar System.
8. The time it takes for a planet to complete one full rotation on its axis.
10. A moon in orbit around a planet.
13. A collection of stars that make a pattern in the sky.
15. A model of the Solar System with the Sun at the centre.
16. The length of time a planet takes to orbit a star.
17. The imaginary line which a planet spins on.

1. The distance light travels in a year.
3. Changes in temperature during the year as the Earth orbits the Sun
4. Path taken by one object moving around another larger object.
5. Collection of stars held together by gravity.
6. A model of the Solar System with the Earth at the centre.
9. A manmade spacecraft.
11. Lump of rock orbiting the Sun left over from when the Solar System was formed.
12. Any large body that orbits a star in a Solar System.
14. The Sun and the planets and other bodies in orbit around it.