A star exploded just 625 million years after the Big Bang, but the radiation of this event didn’t reach Earth until last spring. This gamma-ray burst was named GRB 090423. It is the most distant astronomical object yet discovered. Jochen Greiner and his colleagues at the Max Planck Institute for Extraterrestrial Physics in Garching investigate such cosmic ‘ignition sparks’ at the edge of space and time.
