Secrets Of The Mariana Trench, Caught On Camera

Deep in the ocean, a mission is underway to explore the "unknown and poorly known areas" around the Mariana Trench. "Despite decades of previous work in the region," the National Oceanic and Atmospheric Administration says, "much of the [trench] and surrounding areas remain unexplored."...
http://www.npr.org/sections/thetwo-way/2016/05/06/477085814/secrets-of-the-mariana-trench-caught-on-camera?ft=nprml&f=1001