A cosmic ray detector on the International Space Station has found the footprint of something that could be dark matter, the mysterious substance that's never been directly observed but is believed to... more 
A cosmic ray detector on the International Space Station has found the footprint of something that could be dark matter, the mysterious substance that's never been directly observed but is believed to hold the cosmos together. (April 3) less 
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Wed, Apr 3, 2013 6:45 PM EDT