Discovery Education has eight projects on the Solar System that you can do with a class or a single child. Many of them are also great projects for a science fair or a report. This website also has games to play and some ideas on how to get your students or children interested in space as well as a quiz to make sure that the material has been mastered.
Cool Science Projects has some suggestions on various projects for a science fair as well as some background material on the Solar System.
Enchanted Learning has a number of Solar System crafts that are simple enough for young children probably in kindergarten or grades 1 through 3. There are also coloring pages about the Solar System that can be printed.
The AOK Corral has a project painting a glow in the dark Solar System, which is a great twist on an old classic. You can take the idea of using the glow in the dark paint a step further and create a glow in the dark mural for a kid’s room.
How Stuff Works has some great projects for kids including one on how to make your own planetarium and learning how to create your own astrolabe.
A to Z Home’s Cool Homeschooling has a ton of links to great projects and experiments you can try. Some of these links let you figure out your weight on other planets. You can also get information on all the planets in the Solar System.
One of the best resources for your space needs is NASA. NASA has materials for children including games to play and projects for science fairs as well as information on the planets and all the other objects in the Solar System. They also have materials for children of different ages and even resources for college students. NASA even has information on how to get a guest speaker from NASA at your school.
Universe Today has articles on what the Solar System is and all the planets.
For more information check out an overview of the Solar System and the Solar System for kids.
Astronomy Cast has episodes on all the planets including Jupiter.