... Callisto's surface shows its age. ... Stars Without Galaxies . ... Galaxies are made up of stars, but are all stars found within galaxies? Using the Hubble Space Telescope, researchers exploring the Virgo Cluster of galaxies have found about 600 red giant stars adrift in intergalactic space. ... In the top panel you can choose from a myriad of distant galaxies revealed in a deep Hubble Space Telescope image of a narrow slice of the cosmos toward the constellation Hercules. ...