This image made by the NASA/ESA Hubble Space Telescope shows M66, the largest of the Leo Triplet galaxies. It has asymmetric spiral arms and an apparently displaced core most likely caused by the gravitational pull of the other two members of the trio. 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)