The European Space Agency’s space-based infrared astronomical observatory,called Herschel — named after William Herschel, who discovered infrared light in the late 18th century — peered into the sky for just under four years. Until April 2013, and when it finally ran out of the coolant needed to chill its detectors,it took images of the heavens, looking at wavelengths of light far, and far external what our mere human eyes could perceive.
Source: blastr.com