Space scientists have found proof of the existence of a major component of the universe – even though it can never be seen.
They discovered conclusive evidence that the cosmos is filled with something called dark matter by watching the most dramatic event witnessed since the Big Bang.
Observations of a tremendous collision between two large clusters of galaxies revealed dark matter and normal visible matter being wrenched apart.
The Hubble telescope, Nasa’s X-ray observatory in space, Chandra, and some of the biggest observatories on Earth were used to study a colection of galaxies called the Bullet Cluster, or 1E0657-56.
They found a 100 million-degree hot gas cloud was bound up with the galaxies – something that would be impossible without the gravitational pull of an even greater amount of dark matter in the region.
Astronomers believe that visible material such as stars, gas clouds and galaxies make up less than a 20th of the universe. They suspected the presence of a mysterious invisible component by studying the gravitational pull of galaxies on each other which are much stronger than predicted by Einstein.
Dark matter is thought to be responsible and could form as much as 22 per cent of the universe. The remaining 74 per cent is believed to be something even more peculiar – dark energy.
Discovery team leader Doug Clowe, of the University of Arizona, said: “A universe that’s dominated by dark stuff seems preposterous, so we wanted to test whether there were any basic flaws in our thinking. These results are direct proof that dark matter exists.”