Gamma rays have the most energy and smallest wavelengths of any form of light in the electromagnetic spectrum. Extremely energetic events generate them. Our atmosphere absorbs incoming gamma rays, so we detect them with observatories in space.
On January 31, 1993, the Compton Gamma Ray Observatory recorded the "Superbowl Burst," a flood of gamma rays pouring out from an object in space. This image (left) targets the source's location near the constellations Virgo and Corvus.
Gamma-ray bursts can appear anywhere in the sky and then quickly vanish. Some could be caused by collisions between black holes or by neutron star-black hole mergers.