January 11, 2011

NASA Telescope Detects Atmospheric Antimatter

NASA scientists have discovered beams of antimatter being produced by thunderstorms here on Earth--a phenomenon that had never been observed before, the US space agency said on Monday.

It is believed that the antimatter particles were formed in a terrestrial gamma-ray flash, or TGF. According to a NASA press release, about 500 of these lightning-related events occur each day, but most of them are undetected. This one was spotted using NASA's Fermi Gamma-ray Space Telescope.

"These signals are the first direct evidence that thunderstorms make antimatter particle beams," Michael Briggs, a member of Fermi's Gamma-ray Burst Monitor (GBM) team at the University of Alabama in Huntsville (UAH), said during a Monday news briefing at the Seattle-based American Astronomical Society, where the findings were first presented.

According to NASA, the Fermi telescope is designed to monitor gamma rays throughout the universe, and has identified 130 TGFs since 2008. The GBM has detected gamma rays with energy levels exceeding 500,000 electron volts, which officials at the American space program say only occurs when an electron comes into contact with a positron, its antimatter counterpart.

"One of the great things about the Gamma-ray Burst Monitor is that it detects flashes of gamma rays all across the cosmic scale," Julie McEnery, one of the Fermi project scientists, told BBC News Science and Technology Reporter Jason Palmer on Tuesday.

"We see gamma-ray bursts, one of the most distant phenomena we know about in the Universe, we see bursts from soft gamma-ray repeaters in our galaxy, flashes of gamma rays from solar flares, our solar neighborhood - and now we're also seeing gamma rays from thunderstorms right here on Earth," she added.

Briggs also told Palmer that this discovery provides the first evidence "that TGFs produce not just gamma rays but also produce positrons," and Duke University atmospheric electricity expert Steven Cummer told BBC News that the finding was "truly amazing."

"I think this is one of the most exciting discoveries in the geosciences in quite a long time--the idea that any planet has thunderstorms that can create antimatter and then launch it into space in narrow beams that can be detected by orbiting spacecraft to me sounds like something straight out of science fiction," he told Palmer.

"It has some very important implications for our understanding of lightning itself. We don't really understand a lot of the detail about how lightning works. It's a little bit premature to say what the implications of this are going to be going forward, but I'm very confident this is an important piece of the puzzle," Cummer added.

A paper detailing their findings is scheduled to be published in the journal Geophysical Research Letters, the publication of the American Geophysical Union.


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