Thunderstorms Proven To Create Antimatter

radioweather writes "Scientists using NASA's Fermi Gamma-ray Space Telescope have detected beams of antimatter from thunderstorms in the form of positrons hurled into space. Scientists think the antimatter particles were formed in a terrestrial gamma-ray flash, a brief burst produced inside thunderstorms and shown to be associated with lightning. '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. He presented the findings at a news briefing at the American Astronomical Society meeting in Seattle."

Re:Death ray?

[TheRaven64]

Harvesting antimatter is incredibly hard. It's not like you can just stuff it in a shoe box. You need to make sure that it doesn't come into contact with any normal matter. This means putting it in a vacuum and using magnetic fields to make sure that it doesn't touch the sides of the container. Scientists only managed to make a stable antimatter container for the first time a few months back.

Re:So, here's a question...

[AlecC]

I doubt strongly that they are being formed "without a matter counterpart". That would violate a number of cherished conservation rules. A positron/electron pair is formed when a gamma ray of sufficient energy passes close to a nucleus. But it would be difficult to detect the new electrons in the maelstrom of displaced electrons that is a thunderstorm, whereas the positrons are extremely distinctive,

Sprites / elves?

[popoutman]

This is most likely related to the phenomena known as Sprites, Jets or Elves, that have been captured coming from the tops of thunderclouds. Better explanations here http://www.sky-fire.tv/index.cgi/spritesbluejetselves.html [sky-fire.tv]

Re:So, here's a question...

[toppavak]

Indeed, the positrons are not escaping into space, even at an altitude of 100km, the mean free path in atmosphere is on the order of cm. TFA has it right although slightly distorted (the summary is totally off). The generation of the positron / electron pair results in an annihilation event quite rapidly as the positron travels away from its generation point. What is being observed in orbit is the 511.4 keV photon (gamma ray) that is generated as a consequence of the annihilation. Hence why a gamma ray observatory was able to detect the events.

Re:What gave them the idea?

[GammaRay Rob]

Terrestrial Gamma Flashes have been detected by orbiting instruments for some time; at least since 1991,iirc. What's new here is the definite signature of positron annihilation; this can only be done with a sufficiently large detector looking at the right energy. The Burst Monitor on Fermi was designed to catch the medium energies of gamma-ray bursts (as well as low- and high energies), so this was a nice add-on to the main science.