New research has confirmed the old theory that a layer of antimatter particles encircles Earth. The discovery that a band of antiprotons lie in the magnetosphere, which is beyond the Van Allen belt, proves earlier prediction that Earth's magnetic field could trap antimatter.

According to researchers, the new discovery could help science leapfrog several hurdles in its advanced space exploration projects in future. According to them, the antimatter belt could be a fuel powerhouse, trapping enough energy to fuel a spacecraft.

The study, conducted by Italian, Swedish and Russian scientists, is titled "The Discovery of Geomagnetically Trapped Cosmic-ray Antiprotons," and is published in Astrophysical Journal Letters.

The Van Allen belt lies at an altitude of several hundred kilometers above Earth and is a torus of energetic charged particles around Earth, which is held in place by Earth's magnetic field. Most of the particles that form the belt come from solar storms, while other particles are from cosmic rays.

According to Alessandro Bruno of the University of Bari, who is a co-author of the study, the band is the most abundant source of antiprotons near the Earth.

The discovery, which is the first of its kind, can help humanity in manifold ways. It could help scientists explore the stars, and according to researchers, the belt of antimatter could be used as a source of fuel, an idea already being explored by NASA's Institute for Advanced Concepts.

The antimatter particles ringing around earth were discovered using PAMELA -- a cosmic-ray detector attached to a Russian satellite. PAMELA was launched in 2006 to study the nature of high-energy particles from the Sun and from beyond our solar system.

Scientists observed an unusually higher number of antiprotons when the Pamela satellite passed a region called the South Atlantic magnetic anomaly. The finding showed the number of antiprotons in this belt was a few thousand times more than what would normally be detected as a result of particle decay.

This proved that there is an antiproton belt that keeps these antiprotons together. The South Atlantic Anomaly is a region of space where the Van Allen Radiation Belts are the closest to Earth.

"We are talking about of billions of particles," Francesco Cafagna from the University of Bari in Italy told "New Scientist" magazine.

According to Bruno, trapped antiprotons decay during their interaction with molecules in the atmosphere, especially at low altitudes, where mutual annihilation becomes the main mechanism of disintegration.

When matter and antimatter annihilate each other, all their mass is turned into energy, so even a small amount of antimatter can release an enormous amount of energy. One gram of antimatter, annihilating 1 gram of normal matter, can generate as much energy as 23 Space Shuttle external fuel tanks.

"At the high altitudes of several hundred kilometers, the decay rate is significantly lower, allowing the existence of large quantities of antiprotons," said Bruno.