The 12,500-tonne Compact Muon Solenoid experiment (CMS) in Cessy, France, uses key information about particles emerging from high-energy proton collisions in the Large Hadron Collider (LHC) to unearth nature’s secrets. CMS’s method of construction is original and unique in that “slices” of detector weighing as much as 2000 tonnes were fully constructed and tested with the acquisition and analysis of cosmic ray data on the earth's surface and then lowered 100 metres into the cavern, ready-made. CMS has been fully operational, recording and analyzing large volumes of cosmic ray data as well as the data from the circulation of the the first LHC beams on Sept 10 2008. It intends to make discoveries that will assist in the description and characterization of the composition of the Universe, its beginning, evolution and its intricate works.