Solar System Scope is an web-based interactive that lets the user view the Solar System from a Heliocentric view, Geocentric view, or Panoramic view. In the Heliocentric view you can move a planet forward and back in time to see the relative positions of the sun and planets. It looks like many features will be added to Solar System Scope in the future. Any teacher of Earth in Space concepts should check it out.
You may also want to visit and “like” the Solar System Scope Facebook page.