Gamma-rays have the smallest wavelengths and the most energy of any other wave in the electromagnetic spectrum. These waves are generated by radioactive atoms and in nuclear explosions. Gamma-rays travel to us across vast distances of the universe, only to be absorbed by the Earth's atmosphere. Different wavelengths of light penetrate the Earth's atmosphere to different depths. Instruments aboard high-altitude balloons and satellites like the Compton Observatory provide our only view of the gamma-ray sky.
             Gamma rays are the most energetic form of light and are produced by the hottest regions of the universe. They are also produced by such violent events as supernova explosions or the destruction of atoms, and by less dramatic events, such as the decay of radioactive material in space. Things like supernova explosions (the way massive stars die), neutron stars and pulsars, and black holes are all sources of celestial gamma rays.
             Gamma ray bursts of GRB fall into one of two categories. Less than two seconds: short, and longer than two seconds: long. They occur isotropically, they are spread evenly over the entire sky. This contradicts the existing perception that burst came from sources within the Milky Way; if they did, the shape of our galaxy should have caused them to bunch up in certain areas of the sky. This uniform distribution led astronomers to conclude that this event was happening throughout the universe. Unluckily, this alone did not supply sufficient information to settle for sure.
             An interesting discovery has been the connection between GRBs and supernovae by the detection of iron in the x-ray spectra of several bursts. Iron atoms are known to be synthesized and dumped into interstellar space by supernova explosions. Additional observations further support the connection between GRBs and supernovae, it has been found that emission lines f...