People，animals and plants all live on the Earth．The Earth turns around itself once 24 hours．This is why there is a day and a night Oil the Earth．The Earth goes around the sun once a year for giving us different seasons．The moon moves around the Earth．The sun is much bigger than the moon．But the moon looks bigger than the sun because it's much nearer to the Earth．The sun is very bright．It gives out a very strong light．The moon looks quite bright，too．But it can't give out any light at all．