"HUNTSVILLE, Ala. -- For the first time, antimatter has been observed occurring naturally on Earth, as scientists using NASA's Fermi Gamma-ray Space Telescope have documented beams of antimatter produced above thunderstorms.
The scientists think the antimatter particles are formed inside thunderstorms in terrestrial gamma-ray flashes associated with lightning. They estimate that about 500 gamma-ray flashes occur daily worldwide, but most go undetected.
"These signals are the first direct evidence that thunderstorms make antimatter particle beams," said Michael Briggs, a member of Fermi's Gamma-ray Burst Monitor team at the University of Alabama in Huntsville. He presented the team's findings last week at the American Astronomical Society meeting in Seattle."