NASA’s new GBM telescope has detected beams of antimatter produced above thunderstorms on Earth by energetic processes similar to those found in particle accelerators. Scientists think the antimatter particles are formed in a terrestrial gamma-ray flash (TGF), a brief burst produced inside thunderstorms that has a relationship to lighting that is not fully understood. As many as 500 TGFs may occur daily worldwide, but most go undetected.
During one TGF, which occurred on December 14, 2009, the NASA Fermi spacecraft was located over Egypt, while an active storm was in Zambia, 2,800 miles to the south. The distant storm was below Fermi’s horizon, so Fermi could not see the storm from its position in orbit, thus any gamma-rays it produced could not have been detected directly. The antimatter particles from the storm travelled up along the Earth’s magnetic field lines and struck the spacecraft. The beam continued past Fermi to a distant point, where its motion was reversed, and then it hit the spacecraft again. Researcher Michael Briggs says, "These signals are the first direct evidence that thunderstorms make antimatter particle beams."