Thunderstorms Make Antimatter as Well as Noise

A high-powered, space-based particle detector has found the first evidence of antimatter being produced naturally on Earth — in thunderstorms. We generally think of antimatter as cosmic rays that are produced by the sun or during a nuclear reaction. But it is used commonly in medical brain scans. Until recently, scientists had never captured any sign of natural antimatter being produced terrestrially.

At this week’s American Astronomical Society meeting in Seattle, astrophysicist Michael Briggs unveiled his findings. NASA’s Fermi telescope caught thunderstorms ejecting bursts of antimatter into space. Now scientists believe that the antimatter was created during a terrestrial gamma-ray flash (TGF).

Gamma Ray Burst Sets off TGF along Earth's Magnetic Field during a Big Thunderstorm

The phenomenon has something to do with lightning although scientists don’t quite understand why antimatter is made in the process. But the process goes something like this.

A TGF produces high-speed electrons and positrons, (the antimatter equivalent of electrons) which then ride the arc of Earth’s magnetic field where they intercept the orbiting telescope.

The Fermi Gamma-ray Space Telescope, which has been circling the Earth for less than three years, is designed to monitor gamma rays, the highest energy form of light. When antimatter collides with a particle of normal matter, both particles immediately annihilate and transformed into gamma rays. In the case of thunderstorms, the gamma-ray burst is called a TGF.

While TGFs create beams of electrons and positrons, not all thunderstorms produce TGFs. Though most aren’t detected by the space telescope, NASA believes that about 500 TGFs occur every day around the world.

Most of the time, we think of antimatter as something that exists only in the deepest corners of the cosmos or in science fiction.

The universe is filled with matter — everything that has mass is matter. But scientists don’t know what happened to all the antimatter. Conventional wisdom holds that matter and antimatter should have been created in equal amounts. But when one comes into contact with the other, they annihilate instantly. Yet the universe is filled with matter but has no large source of antimatter.

Now we see there is at least one natural way to produce antimatter here on Earth — giant thunderstorms.