Humans have stepped foot on the moon more times than we've been to the deepest floors of our oceans. As science looks to survey new species, prospect minerals, and monitor how climate change is altering the depths, engineers need to find new ways to get us there, or at least send our mechanical eyes and ears.
Woods Hole Oceanographic Institution (WHOI) has built Nereus  (rhymes with “serious”) to get us there. A remotely operated vehicle (ROV) that can hit 11,000 meters underwater--that's almost twice the height of Everest--without any trouble, Nereus is a test bed for a new suite of technologies  shedding ROVs clunky, ship-tethered past.
Nereus is among a new class of underwater robotic vehicles being designed to autonomously explore some of the harshest environments in our oceans and better understand our atmosphere. The ROV menagerie is being operated by WHOI , NOAA  and a handful of other institutions, to allow us to conduct long-term science in harsh undersea and ice-covered environments such as the waters around Antarctica and Greenland, whose changes in climate and sea level are most acute.
Powered by 3,000 lithium-ion batteries, the ROV can autonomously map underwater landscapes then return safely to the research ship under its own power. For more complex missions, where two-way communication is needed, a slender fiber-optic cable the diameter of a human hair allows Nereus to find its target and use a seven-foot hydraulic arm, as well as other sensors, to collect samples. Last year, an experimental system merging acoustics and optics demonstrated that Nereus can cut the cord completely and still communicate with the surface.
Nereus has already navigated one of the deepest parts of the ocean, the Challenger Deep. It will soon be turned toward the cold and dark places under the Arctic ice, to learn more about how the chemistry of those deep waters are changing and, perhaps, what we can do to forestall that change.
[Image: Wikipedia ]