It sounds like the stuff of science fiction, but scientists are reporting that they have seen antimatter beams emitted from thunderstorms. Jonathan Palmer has the story at BBC News:
A space telescope has accidentally spotted thunderstorms on Earth producing beams of antimatter.
Such storms have long been known to give rise to fleeting sparks of light called terrestrial gamma-ray flashes. But results from the Fermi telescope show they also give out streams of electrons and their antimatter counterparts, positrons.
The surprise result was presented by researchers at the American Astronomical Society meeting in the US.
It deepens a mystery about terrestrial gamma-ray flashes, or TGFs — sparks of light that are estimated to occur 500 times a day in thunderstorms on Earth. They are a complex interplay of light and matter whose origin is poorly understood.
Thunderstorms are known to create tremendously high electric fields — evidenced by lightning strikes.