Some of the most dramatic events in the universe occur when certain stars die — and explode catastrophically in the process. When these star deaths, or supernovae, occur, their brightness can rival the light of a whole galaxy. The galaxy NGC 5468, shown in this Hubble image, has hosted a number of these supernovae the past 20 years.
Luca Parmitano Works to Upgrade a Cosmic Particle Detector
European Space Agency astronaut and current International Space Station Commander Luca Parmitano and crewmate Andrew Morgan (out of frame) performed the third spacewalk to repair the Alpha Magnetic Spectrometer.