Antimatter found in bands around Earth

A thin belt of antimatter particles surrounding Earth has been detected for the first time, an article in a British astrophysical journal reports.

The published findings in Astrophysical Journal Letters confirm previous theoretical work that predicted antimatter, in the form of anti-protons, could be trapped by Earth's magnetic field.

A small number of anti-protons lie between the Van Allen belts of magnetically trapped "normal" matter, scientist say.

The anti-protons were detected by a satellite launched in 2006 to study the nature of cosmic rays, high-energy particles arriving at Earth from both the sun and from beyond the solar system.

The band is "the most abundant source of anti-protons near Earth", study co-author Alessandro Bruno of the University of Bari in Italy told BBC news.

The magnetic field holds the anti-protons in place until they encounter particles of normal matter in Earth's atmosphere, when they are annihilated in a flash of light, the scientists said.