Children start learning about the solar system--the sun and the eight planets that revolve around it--in elementary school, and there are several educational projects you can do with them in the classroom or at home to reinforce what they are learning.
The mnemonic device "My Very Excellent Mother Just Served Us Nine Peanuts" was once used to help students remember the order of the planets in the solar system (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto). However, Pluto is no longer considered a planet, so children can come up with new mnemonic devices. Give the children pencil and paper and encourage them to write a sentence, poem, song, rap or short story to help them remember the order of the planets.
Cookie Solar System
Bake nine cookies, one for each of the planets and the sun. The cookies should be of different sizes. Use three large cookies to represent the sun, Jupiter and Saturn, two medium-sized cookies for Neptune and Uranus and four smaller cookies for Mercury, Venus, Earth and Mars. Have the children decorate the cookies with coloured icing to look like the planets. You could use liquorice to make Saturn's rings and a hard candy for Jupiter's eye. Put the cookies out in the correct order to reflect the solar system.
Papier-Mache Solar System
Blow up nine balloons--one for the sun and eight for the planets. Make the balloons different sizes, with the largest used for the sun and the smallest for Mercury. You can make some smaller balls for dwarf planets and asteroids if you wish. Cut newspaper into long strips and make papier-mache paste by mixing either two cups of water and one cup of glue or 1 1/2 cups of water and 1/2 cup of flour. Dip the strips of paper into the paste and layer them over the balloons. There should be four or five layers over the balloons. Allow them to dry for 24 hours then have the children paint the balloons to look like the planets and the sun and hang them from the ceiling.
Buy modelling clay in several different colours and have the children make a model of the solar system. Try to include some of the comets, the asteroid field between Mars and Jupiter and dwarf planets, such as Pluto.