Thu July 5, 2012 8:05pm
IT should have been there. But it's never been seen. But, now, scientists believe they have found "dark matter" weaving through space between galaxies.
Scientists report discovering wisps of dark matter - which have a gravitational influence on galaxies but have never been seen - forming filaments linking galaxies and clusters across mostly empty space.
Dark matter is believed to make up roughly 85 per cent of all mater in the universe, but has proven extremely difficult to observe.
Exactly what dark matter is remains unknown.
A team led by Jorg Dietrich at the University Observatory in Munich, Germany, reports detecting dark matter in a filament near a supercluster of stars called Abell 222/223 about 2.7 billion light years away.
The dark matter was shown to exist by calculating how much normal hot gas was in the region as compared to how much gravitational influence there was on light from distant galaxies behind the filament. The gas was shown to provide only 10 per cent of the mass, with the remainder being dark matter.
The discovery of these dark-matter filaments, about 58 million light-years from end to end, are predicted to contain more than half of all matter in the Universe, was published online Wednesday by the journal Nature.