Heavy-duty mining robots can now dig for gold in rocky, underwater landscapes at depths of as much as two kilometers. Earlier this year, a Canadian company, Nautilus Minerals, dispatched a specially designed underwater mining robot to conduct the world's first commercial deep-sea search for gold and copper, off the coast of Papua New Guinea in a mountainlike landscape 1,600 meters below sea level.

The feat was made possible through a marriage of advanced 3-D mapping technology and heavy-duty mining gear. Nautilus started with a deep-sea ROV (remotely operated vehicle) normally used by the oil and telecom industries; the company customized it by adding drilling and cutting tools hitherto used only on land.