The universe is a dark, dark place: evidence of 'dark matter' found

Scientists from the University of Arizona have discovered evidence proving that dark matter in the universe actually does exist.

Since the 1930's scientists have theorized the existence of dark matter - so much of it, that there is at least five times more dark matter in the universe than normal matter.

Although it couldn't be ssin, astronomers assumed it must be there because of the way gravity works - though there were some alternative theories.

Now dark matter has been seen. Using NASA's Chandra X-ray Observatory, the researchers took images of two large clusters of galaxies merging. The process is thought to go on all the time, but this view - only 100 million years after the merger - allowed for a close-up peek at the outcome.

The merger showed a distinct separation between the dark and normal matter.

Bending light to form the picture
A galaxy cluster's normal mass is in its hot gas clouds, which are left behind after a merger of this sort, the scientists say.

But when the researchers observed the area around these galaxies, they discovered there was far more mass than the clouds.

To be sure, the team analysed gravitational lensing - when gravity bends light around distant objects, like galaxies - in this area using projected images from three additional observatories: NASA's Hubble Space Telescope, the European Southern Observatory's Wide-Field Imager and one of the two Magellan telescopes.

By viewing the shapes and patterns that were made from the distorted light, the researchers found a mass of non-luminous - or dark - matter that was a far greater mass than the normal matter.

The scientists say that the next step would be to analyse what this dark matter is made of, now that it has been discovered.

The research will be published in the upcoming issue of the Astrophysical Journal Letters.

Photography: San Diego Supercomputer Center

Source: Discovery Channel Reports, August 24 edition