NASA
Nasa: Kepler's Third Law
This site from NASA states Kepler's third law of motion and extends it to develop an equation for the velocity of an orbiting planet.
Science and Mathematics Initiative for Learning Enhancement (SMILE)
Smile: Paper Mache Solar System
This site from the Illinois Institute of Technology provides a set of directions for the creation of a solar system model out of paper mache. Includes orbital distances and planet diameters for the nine planets. Great idea for a student...