
On Aug. 6 at 22:30 UTC (6:30 p.m. EDT) NASA's Aqua satellite passed over Hurricanes Iselle (right) and Julio (left) approaching Hawaii. This image was created using three satellite passes.
NASA's Fermi Gamma-ray Space Telescope is designed to detect the brightest explosions in the universe - gamma-rays emitted from sources like supermassive black holes or stars that go supernova. But gamma-rays, which are invisible to the naked eye and last only a few thousandths of a second, can also come from sources on Earth.
On Monday (Aug. 4) at 4:19 a.m. EDT (0819 GMT), when Julio was still a fledgling tropical storm hundreds of miles off the coast of Mexico, Fermi witnessed what's known as a terrestrial gamma-ray flash (TGF) above the clouds, according to NASA. [Elves, Sprites & Blue Jets: Photos of Earth's Weirdest Lightning]















Comment: Read Pierre Lescaudron and Laura Knight-Jadczyk's new book, which offers plenty of explanations from the winning Electric Universe model; demystifying increasingly common phenomena such as lightning, earthquakes, volcanic activity, sinkholes and other earth changes!