1)   GrandTour 4.1
Accurate, flexible wireframe simulator for the Voyager and Giotto space missions, with animation capability. Developed at JPL for science/navigation, and filmed by the BBC/NOVA. Conveniently runs from any Windows/DOS.
Voyager, Giotto, space, mission, simulator, planet, comet,

 2)   MaterialWorlds Simulations 1.5
Live interactive physics simulations let you explore the Solar System (orbits, seasons, gravity, tides, comets and satellites), play snooker and experiment with Laws of Motion, bridge,crash,ideal gas,pendulum clock and siege engine simulations.
virtual reality, science, physics, experiments, simulation, games, solar system, geocentric, astronomy, earth,

 3)   Deep Space Fantasy Screen Saver 1.0
30 Computer artwork images of deep space, alien worlds, stars, planets, black holes, comets, and wormholes.
space, deep space, scifi, science fiction, alien, planet, nebula, nebulae, blackhole, black hole,

 4)   Comet 1.2
The comet screensaver displays a comet swooping over your screen, lighting up your darkened desktop. Options: Fiery Comet, Turbulence and Screen Burn.
screensaver, space, comet,