Cool Solar System Exploration Site. The space weight is a great activity to show students how much they weigh on at he moon or a certain planet. You could also do the weight of objects if students do not want to weight themselves.
Planet game-Stencil planet names and point values onto paper bands. The farther away a planet is from the sun, the more points it should have (it'll be harder to throw a rocket into it). Tape the bands onto buckets. Place buckets on rope rings. To make the sun, glue a round piece of yellow paper to cardboard.