BATSE mission gamma ray burst map. This map shows 2704 gamma ray bursts (GRBs) detected by NASA's Burst and Transient Source Experiment (BATSE) mission carried on the Compton Gamma Ray Observatory in Earth orbit from 1991 to 2000. The GRBs are shown as coloured dots across the whole sky, with the length and brightness (fluence) colour-coded (key at bottom). Purple are short, weak GRBs, while red are long, bright GRBs, and grey dots lack data to calculate the fluence. GRBs are extremely high-energy events that can be seen far across the universe. They may be the result of neutron stars being torn apart by black holes.