A great mystery was set in motion a few years ago when a spacecraft designed to measure gamma-ray bursts -- the most powerful explosions in the Universe -- found that Earth was actually emitting some flashes of its own.
So? Terrestrial GRB were common back a few decades back during the age of above-ground nuclear tests. Indeed, the first cosmic GRB were detected by the VELA test-monitoring satellites. The fact that lightning flashes can created small GRB is interesting and should be studied more, but doesn't detract from the significance of investigating the origin of cosmic GRB.
Articles, opinions and rants from an astrophysicist: Cosmic Journeys