What was found by three graduate students — Kirsten Lorentzen of the University of Washington and Robin Millan and Jason Foat of the University of California at Berkeley — has scientists scrambling for an explanation: an intense stream of X-rays, occurring in seven bursts, each separated by only a few minutes and lasting for a total of half an hour. The evidence was clear that the high energy bursts came not from outer space, but from the Earth’s upper atmosphere.
December 9, 1997