Muon detector important for imaging and monitoring carbon dioxide storage sites
(PHYSorg.com Physics)

Invisible to the naked eye, muons are elementary particles created by the collisions of cosmic rays with molecules in the upper atmosphere. These muons are constantly beaming down on the earth`s surface at various angles. Because muons pass through materials, scientists since the 1960s have turned to them to `see` the inside of structures, such as the pyramids of Giza.