Today in school, we'll be making models of the Solar System. I found the projects here. I'll post pictures of how they turned out once we're finished.
One nice thing about the internet is how much information you can use to homeschool your children. There is so much free information out there that monetary issues shouldn't really come into play when it comes to a decision to homeschool. I even found an astronomy course for children online (though I do need to be careful to point them towards sites that aren't contradictory to our Catholic faith, such as ones that don't misrepresent what went on with Gallileo).