... scientists using NASA’s Fermi Gamma-ray Space Telescope discovered a previously unknown phenomenon that occurs above thunderstorm clouds.
It turns out that in addition to producing rain and lightning, thunderstorm clouds also produce antimatter. The discovery is the first time antimatter has been found to be created naturally on Earth. Antimatter particles are created within a terrestrial gamma-ray flash (TGF) which is produced inside thunderstorms in association with lightning. These TGFs occur around 500 times a day, but the vast majority go undetected. Gamma rays contain a high amount of energy and occur when particles of antimatter strike normal matter. TGFs with energies of 511,000 electron volts have been detected by Fermi.
The Fermi spacecraft was originally designed to detect high-energy events in space. Scientists have now found that the spacecraft can be a valuable in detecting high-energy events occurring on Earth as well. [emphasis mine]