Mysterious 'dark matter' is mapped at last - a 'cosmic web' spanning a billion light years

• Substance undetectable by normal telescopes
• Huge mass detected by its gravity 'bending' light
• Astronomers scanned 10 million galaxies

'Dark matter' is a theoretical - and controversial - substance which is undetectable by telescopes on earth, but thought by some scientists to account for up to three quarters of the mass of the whole universe.

But scientists have mapped it for the first time, detecting dark matter by the 'ripples' it causes in space and time.

Scientists studied 10 million galaxies in four regions of the sky using a 340 megapixel camera in Hawaii, looking for dark matter by the distortion of light from galaxies behind it - the gravity from dark matter 'bends' the light on its journey to us

Read more: http://www.dailymail.co.uk/sciencetech/article-2084363/Mysterious-dark-matter-mapped--showing-cosmic-web-spanning-billion-light-years.html