Celestia is a free real-time space simulation that lets you experience our
universe in three dimensions.  Unlike most planetarium software, Celestia
doesn't confine you to the surface of the Earth.  You can travel throughout
the solar system, to any of over 100,000 stars, or even beyond the galaxy.

All travel in Celestia is seamless; the exponential zoom feature lets you
explore space across a huge range of scales, from galaxy clusters down to
spacecraft only a few meters across.  A "point-and-goto" interface makes it
simple to navigate through the universe to the object you want to visit.

Celestia is expandable.  It comes with large catalog of stars, galaxies,
planets, moons, asteroids, comets, and spacecraft.  If that's not enough,
you can download dozens of easy to install add-ons with more objects.

WWW: http://www.shatters.net/celestia/
