Hubble Space Telescope Photo Gallery

This image made by the NASA/ESA Hubble Space Telescope shows the tattered remains of a supernova explosion known as Cassiopeia A. It is the youngest known remnant from a supernova explosion in the Milky Way. The Hubble Space Telescope marks its 25th anniversary. A full decade in the making, Hubble rocketed into orbit on April 24, 1990, aboard space shuttle Discovery. (NASA, ESA, Hubble Heritage STScI/AURA-ESA/Hubble Collaboration via AP)