Scientists discover key to dark matter

Astronomers are now able to map dark matter on the largest scale ever observed by studying images from galaxies six billion light years away, thanks to a recent study.

The research was led by Dr Catherine Heymans of the University of Edinburgh and Associate Professor Ludovic Van Waerbeke of the University of British Columbia in Canada.

Their project is known as the Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS).

Dark matter does not emit or scatter light so it cannot be seen directly using a telescope.

The concept was originally conceived to account for differences in calculations of mass between galaxies, clusters of galaxies and the entire universe.

Due to its 'invisible' nature, studies on dark matter have to be done by observing how it affects matter surrounding it.

Dr Catherine Heymans, also a lecturer at the University of Edinburgh's School of Physics and Astronomy, said: "By analysing light from the distant universe, we can learn about what it has travelled through on its journey to reach us.

"We hope that by mapping more dark matter than has been studied before, we are a step closer to understanding this material and its relationship with the galaxies in our universe."

Dark matter was discovered by Fritz Zwicky in 1934. However, not much progress has been made in understanding its properties, leaving it prey to much speculation by popular science-fiction culture.

Professor Ludovic Van Waerbeke, from the University of British Columbia, said: "It is fascinating to be able to 'see' the dark matter using space-time distortion. It gives us privileged access to this mysterious mass in the universe which cannot be observed otherwise.

"Knowing how dark matter is distributed is the very first step towards understanding its nature and how it fits within our current knowledge of physics."

The discovery challenges alternative theories stating that dark matter does not exist.

The findings were presented at the American Astronomical Society meeting in Austin, Texas on Monday 9 January.