New light on 'dark matter'

Scientists said they might be close to tracking down the mysterious "dark matter" which makes up more than a quarter of the universe but has never been seen.

A final identification of what made up the enigmatic material would solve one of the biggest mysteries in physics and open up new investigations into the possibility of multiple universes and other areas, researchers said.

Members of an international team had picked up what might be the first physical trace left by "dark matter" while studying cosmic rays recorded on the international space station, said the head of the Europe- and US-based research project, Samuel Ting.

He told a seminar at the CERN research centre, near Geneva, that the team had found a surge of positron particles that might have come from "dark matter".

In the coming months, he said, the CERN-built AMS particle detector on the space station "will be able to tell us conclusively whether these positrons are a signal for dark matter or if they have some other origin".

"Dark matter", once the stuff of science fiction, "is one of the most important mysteries of physics today", Ting said.

Its existence has long been recognised because of the way it pushes visible stars and planets around.

But efforts in laboratories on Earth and in deep underground caverns to find concrete evidence that it is there, and to establish what it is, have so far proven fruitless.