Your trusted source

One of the world's most capable deep-sea research subs has been lost, the BBC reports.

The robotic vehicle Nereus went missing while exploring one of the ocean's deepest spots: the Kermadec Trench, which lies north east of New Zealand.

Surface debris was found, suggesting the vessel suffered a catastrophic implosion as a result of the immense pressures where it was operating some 10km (6.2 miles) down.

Nereus was a flagship ocean explorer for the US science community.

"Nereus helped us explore places we've never seen before and ask questions we never thought to ask," said Timothy Shank, from the Woods Hole Oceanographic Institution (WHOI), which managed the sub's activities.

"It was a one-of-a-kind vehicle that even during its brief life brought us amazing insights into the unexplored deep ocean, addressing some of the most fundamental scientific problems of our time about life on Earth."

The $8m (£4.7m) robot was built in 2008 and could operate in an autonomous mode or remotely controlled via a tether to a support ship to explore the Earth's deepest oceanic trenches.

It used a lot of innovative technologies that allowed it to do things and go places that were off-limits to other research submersibles.

These technologies included rechargeable lithium-ion batteries, similar to those used in laptop computers, for extended power, and single-hair's-width fibre-optic cables - borrowed from torpedoes - for control and telemetry.