Star Trek fans know that apparently in the future space propulsion is produced through the combination of matter and antimatter. The problem with antimatter though is that it’s scarce and most scientists agree the only way to produce it on Earth is through artificial means. At least, that was the belief until 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. Most of the TGFs detected by Fermi were the result of it being immediately above a thunderstorm, though in four other cases the storms were relatively far away. Those distant storms were detected as a result of TGFs producing high-speed electrons and positrons, an electron’s antimatter counterpart, which rode Earth’s magnetic field to strike the spacecraft.Read more at NASA.