Compare objects as large as the solar system and as small as atoms.
Put things back into correct categories.
Watch an animation of the parts that the space shuttle will deliver.
Try to build the perfect solar system.
Spin the Galex telescope to collect three photons of the same color.
Voyager 1 is carrying a message to anyone or anything out in space.› View Flash →
Hit Earth with a solar event.
Test gases and solids to see their spectra.
Drag the viewfinder to find black holes.