Exploring Earth’s deepest vent in Caymans

A ship packed with U.S.scientists earlier this week set out for a three-week Caribbean cruise to the Mid-Cayman Rise, described as one of the most extreme and least explored places on Earth.

The Washington-based National Science Foundation and the National Aeronautics and Space Administration (NASA) said over the weekend that the 23 scientists aboard the research vessel Atlantis are embarking on a “first-of-its-kind mission” to the Mid-Cayman Rise, also called the Mid-Cayman spreading ridge, a rift in the seafloor some 70 miles (110 kilometers) long and more than 9 miles (15 km) across.

Scientists said that is where geologic forces are shoving two tectonic plates apart, birthing new oceanic crust and fueling what may be “two of the most remarkable hydrothermal vent sites on Earth.”

One vent, the Von Damm, may offer clues to how life first arose on our planet, the scientist said. The other, dubbed the Piccard, lies 16,400 feet (5,000 meters) below the surface — the deepest vent ever discovered on Earth — and may prove to be the hottest, they added.

With the help of a deep-diving robot, the U.S. scientists said they plan to gather the first samples from these oases of strange life on the seafloor.

“We’re guaranteed to find dozens of new species — that’s a no-brainer,” said marine scientist and expedition member Cindy Lee Van Dover, director of the marine laboratory at Duke University’s Nicholas School of the Environment. Duke University is a private research university in Durham North Carolina.

Van Dover said she and the other scientists aboard will be able to collect a wide variety of samples — animals, rocks, seawater — with the help of Jason, a remotely operated vehicle with two arms equipped with pincers at the end.

Beyond the intriguing implications for new species discovery, Van Dover said the Von Damm vent may offer scientists a chance to peer back into the origins of life itself.

At 7,500 feet (2,300 meters) deep, Van Dover said Von Damm is the shallower of the two vents, “yet the rock there is a geological throwback to Earth’s early years, a couple billion years ago.”

She said the site may be one of the few accessible places on the planet where seawater can interact with heated primordial rocks, producing the kind of warm, hydrogen-rich broth scientists suspect gave rise to the world’s first organisms.

“The hydrothermal reactions there are probably our closest modern-day analogue for geology in the first half of Earth’s existence,” said Chris German, chief scientist on the expedition and a geochemist at the Woods Hole Oceanographic Institution in Massachusetts.

That means the Von Damm site could provide a glimpse of the mechanisms that, over the ages, transformed lifeless molecules to living, complex beings, he said.

“If you track (life) down to the lowest denominator — the common ancestor — it speaks to a single-celled organism that thrived in high temperatures and low oxygen environments,” German said. “And deep-sea hydrothermal hot springs fit that bill.”

Although previous research indicates Von Damm is a very good candidate for this process, called abiogenesis, temperature is a key factor, German said.

“If it’s too hot or it’s too cold, it’s no good,” he said. “There’s a Goldilocks zone where it’s just right. Somewhere around 200 to 300 degrees Celsius (390 to 540 degrees Fahrenheit) would be the sweet spot.”

NASA scientists say they are also taking part in the expedition’s work in hopes that data from the Von Damm vent may offer clues to what geological conditions could set the stage for life on other worlds. Europa, one of Jupiter’s moons, is of particular interest, German said.