A thin band of antimatter particles called antiprotons enveloping the Earth has been spotted for the first time.
The find, described in Astrophysical Journal Letters, confirms theoretical work that predicted the Earth’s magnetic field could trap antimatter.
The team says a small number of antiprotons lie between the Van Allen belts of trapped “normal” matter.
The researchers say there may be enough to implement a scheme using antimatter to fuel future spacecraft.
The antiprotons were spotted by the Pamela satellite (an acronym for Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics) - launched in 2006 to study the nature of high-energy particles from the Sun and from beyond our Solar System - so-called cosmic rays.
Among Pamela’s goals was to specifically look for small numbers of antimatter particles among the far more abundant normal matter particles such as protons and the nuclei of helium atoms.
The team says that this is evidence that bands of antiprotons, analogous to the Van Allen belts, hold the antiprotons in place - at least until they encounter the normal matter of the atmosphere, when they “annihiliate” in a flash of light.
The band is “the most abundant source of antiprotons near the Earth”, said Alessandro Bruno of the University of Bari, a co-author of the work.
Dr Bruno said that, aside from confirming theoretical work that had long predicted the existence of these antimatter bands, the particles could also prove to be a novel fuel source for future spacecraft - an idea explored in a report for Nasa’s Institute for Advanced Concepts.