Whoever discovers the nature of dark matter would solve one of modern science's greatest mysteries and be a shoo-in for the Nobel Prize. Yet it's more than just a brainy exercise. Deciphering dark matter - along with a better understanding of another mysterious force called dark energy - could help reveal the fate of the universe.
Previous hunts for the hypothetical matter have turned up nothing, but that has not deterred some two dozen research teams from plumbing the darkness of idled mines and tunnel shafts for a fleeting glimpse.
This is not going to be an easy thing to do. Along with the study of dark energy, this could take quite a while to narrow down.