A small portion of the Veil Nebula - the shattered remains of a supernova that exploded some 5,000-10,000 years ago. The different colors indicate emission from different kinds of atoms excited by the shock: blue shows oxygen, green shows sulfur, and red shows hydrogen. Credit: NASA/ESA/Hubble Heritage/(STScI/AURA)-ESA/Hubble Collaboration/Digitized Sky Survey 2
