An instrument aboard the International Space Station has discovered what may be evidence of the mysterious "dark matter." The material makes up more than a quarter of the universe, but has never been seen.
An international research team said Wednesday said they had found what might be the first physical trace left by dark matter while studying cosmic rays recorded on the International Space Station (ISS). The data was collected by the Alpha Magnetic Spectrometer (AMS), the most sensitive physics spectrometer ever sent to space.
Finding evidence of dark matter, the existence of which has been theorized for 80 years, would solve one of the biggest mysteries in physics as well as open up the investigation of possible multiple universes, researchers said. Previously, dark matter had only been observed indirectly through its effect on visible matter and the phenomenon is not explained by the standard model of physics.
Efforts to find evidence of dark matter underground or in laboratories have thus far been unsuccessful. The team had therefore been looking for dark matter collisions in space because they would be expected to leave a footprint of positrons.
The research team behind the 2.5 billion euro AMS, which was made by a 16-nation team and delivered to the ISS in 2011 on the US space shuttle Endeavour's final flight, said their findings seem to indicate "evidence of a new physics phenomena."
Of the 25 billion cosmic ray events the AMS has studied thus far, "an unprecedented number, 6.8 million, were unambiguously identified as electrons and their antimatter counterpart, positrons," said CERN, the Geneva-based European Organization for Nuclear Research.
Spokesman Samuel Ting said the CERN-built AMS particle detector will in the coming months "be able to tell us conclusively whether these positrons are a signal for dark matter or if they have some other origins."
Ting said his team's evidence "supports the existence of dark matter but cannot rule out" other origins for the positron particles, such as pulsars.
"There is no question we are going to solve this problem," said Ting, a Nobel laureate and professor at the Massachusetts Institute of Technology, adding that dark matter "is one of the most important mysteries of physics today."
dr/jm (AFP, Reuters, AP)