In this fast-paced game, multi-colored photons rain in from all directions. They come from old stars, new stars, galaxies, and glowing gas.  Spin the Galaxy Evolution Explorer telescope around quickly to collect three photons of the same color and record the beautiful space image one piece at a time. This telescope detects ultraviolet photons best, so those count most. Don't let the sticky non-matching photons pile up too high, or the game will end before your picture is complete.

Play Photon Pile-up at http://spaceplace.nasa.gov/en/kids/galex/photon.

And don't get too addicted!