Super sub to dive world's deepest trench

World's toughest submarine gets ready to take the deepest dive

It’s a disconcerting fact that we’ve got better maps of Mars than we have of our own oceans – even though they cover three quarters of the globe. The main problem is that quite a lot of the seafloor is even less hospitable than the red planet: crushing pressures, absolute darkness, colder than freezing. It’s about as inviting as a Mexican swine roast.

So bleak is it that today we’re only prepared to send robots down there. And only one robotic submarine in the world is capable of actually plummeting to the deepest part. This month the Nereus, a semi-autonomous unmanned sub, will dive down nearly seven miles to the bottom of Challenger Deep, the lowest part of the Marianas Trench in the Pacific Ocean - for that matter, the lowest part of the entire planet.

Only two missions have gone to the bottom before: a two-man bathyscaphe, the Trieste, made it to 10,916 metres in 1960, and in 1995 a Japanese robot explorer named Kaiko hit bottom at 10,911m. No human being has been to the very bottom of the ocean since the Trieste.

"I think we are going to see all kinds of new life forms," said Tim Shank, a biologist at Woods Hole Oceanographic Institute, the outfit behind Nereus. "There are going to be novel habitats, novel species and novel adaptations."

Follow the dive at www.whoi.edu

Look out for the WideWorld interview with Dr Don Walsh, the only surviving crew member of the Trieste, next week