Researchers at the Sudbury Neutrino Observatory say they have developed a new technique in the search for dark matter, the invisible substance or group of substances that make up a large percentage of the universe.

The Picasso group, made up of researchers from Canada, the United States and Czech Republic, said the new method will clear out background noise from other particles to give detectors a better shot at finding dark matter signals.

Dark matter is an important part of our picture of the universe - its gravitational influence helps explain why stars at the edges of galaxies appear to move at the same speed as those near the centre, for example.

Because it does not absorb or emit light it is undetectable through direct means. Maps of dark matter have been produced, however, using its gravitational influence on light from distant stars to infer its presence.

While astronomers and physicists believe it is out there, the more vexing question has been: what exactly is it?

One group of candidates is called Weakly-Interacting Massive Particles, or WIMPS. These theoretical particles get their name because they only interact with two of the fundamental forces of nature: gravity and the weak nuclear force.

Because they ignore electromagnetism, WIMPS would be invisible to light or other waves of radiation, and because they ignore the strong nuclear force they would pass through atoms without detection.