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Featured Tool:
All the planets orbit the Sun in the same direction. In what direction do moons orbit their parent planets? Find out by using the Satellite Viewer!



Saturn Ratings

  • Astronomy Classroom
  • Explore the Possibilities
  • Solar System Calculators
  • Solar System Viewers
  • Working With Orbits
  • Orbital Integrators
  • Extragalactic
  • Index of all Tools


  • Thursday's
    Astro Fact:
    Did you know that Europa, one of Jupiter's moons, may have an ocean of liquid water beneath its icy surface? More...
    visits to the Astronomy Workshop since January 1st, 2000. 

    Materials for Students and Instructors.

    Created by Dr. Douglas P. Hamilton and students at U. Maryland. We gratefully acknowledge support from NSF (1998-2003) and NASA (2003-2010). About Us