Get kids to explain the difference between a planet and a star
Ask kids if they know what stars are made of? e.g. Gases such as helium and hydrogen
Ask kids what they think planets might be made of? Do they think they're all made of the same thing? e.g. Jupiter, Saturn and Uranus are made of trapped helium, hydrogen and water. Mercury, Venus and Mars are made of rock.
Ask kids what the difference between stars and planets is? e.g. Stars create light but planets are dark and only reflect the sun's light.