Astronomy Picture of the Day . A GRB 000301C Symphony . ... STIS , HST , NASA Explanation: Telescopic instruments in Earth and space are still tracking a tremendous explosion that occurred across the universe. A nearly unprecedented symphony of international observations began abruptly on March 1 when Earth-orbiting RXTE , Sun-orbiting Ulysses , and asteroid-orbiting NEAR all detected a 10-second burst of high-frequency gamma radiation . ... GRB 990510: Another Unusual Gamma Ray Burst . ...