Though we have come a long way with our knowledge about how the Universe came into being, there is still one mystery that hasn't been solved - that of the mysterious, invisible particles known as 'Dark Matter', which some scientists believe, make up 85% of our Universe.

Over the years, there have been many debates about whether it really exists. Now scientists are trying to put the debate to rest once and for all, by building a deep underground laboratory, where they will conduct special tests to prove the theory . . . . . or not!

Work on what is being described as the 'World's deepest laboratory' began in earnest in June. The lab is located in a former goldmine in South Dakota , an area shielded from the cosmic rays, which may interfere with the experiments. The first laboratory will be built 4,850 feet below the surface of the ground (equivalent to a depth of more than six Empire State Buildings). In the future, scientists hope to build an additional lab even further down, at depth exceeding 8,000 feet.

The idea of 'Dark Matter' was first suggested in 1933. Scientists have always pondered over why our galaxies or star clusters, which move at such great speeds, do not simply fly apart. The fact that they continue to exist, after billions of years, has led many experts to believe that they are made of much more matter, which is holding them together - 'Dark Matter'  invisible to us but with a much higher pull of gravity that holds the galaxies together. Further research has scientists convinced that 'Dark Matter' does not only exist, but makes up 85% of our universe - we are only seeing 15% of the whole.

If this $550 mm USD project proves this theory, it will help scientists better understand how the Universe came into being and, if it is shrinking or expanding.

sources:timesonline.co.uk, switched.com, sanfordundergroundlaboratory.com