Robot sub reaches the world's deepest abyss.

From New Scientist:

A robotic submarine named Nereus has become the third craft in history to reach the deepest part of the world's oceans, at the bottom of the Mariana Trench in the western Pacific Ocean.

The dive to Challenger Deep, an abyss within the Mariana Trench that reaches 11,000 metres beneath the waves, was completed on 31 May by a team from the Woods Hole Oceanographic Institution (WHOI), Massachussetts, US.

For the expedition, the team had to build a new breed of remotely-operated submarine, called Nereus, which is capable of going deeper than any other while still filming and collecting samples. Sunday's dive makes it the world's deepest-diving vehicle, and the first vehicle to explore the Mariana Trench since 1998.