Deepest Hydrothermal Vent Offers Alien Life Model

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Newly found hydrothermal vents, including the deepest active vent ever found, may host extreme life that could reflect the strange and fantastic ways life could have manifested on other planets.

A team of scientists from Woods Hole Oceanographic Institution (WHOI) set out in 2009 to uncover hydrothermal vents along the Mid-Cayman Rise, a slow spreading center located in the deepest point in the Caribbean Sea. The NASA-funded voyage proved to be a gold mine.

The team discovered three hydrothermal vents, including a vent 16,000 feet under the sea along a 100-kilometer (62-mile) stretch, reports a new study in the Proceedings of the National Academy of Sciences.

In a press release by WHOI, chief expedition scientist Chris German explained the uniqueness of their findings:

“We know hydrothermal vents appear along ridges approximately every 100 km. But this ridge crest is only 100 km long, so we should have expected to find evidence for one site at most. So finding evidence for three sites was quite unexpected – but then finding out that our data indicated that each site represents a different style of venting – one of every kind known, all in pretty much the same place – was extraordinarily cool.”

Far from sunlight, deep under the ocean surface, hydrothermal vents sponsor bizarre communities of life not like anything else found on Earth. But these hot spots of life found in extreme geological settings could yield clues to how life may have existed on other planets.

The deepest vent discovered, named Piccard, sits 2,600 feet deeper than the previous recorder holder. This vent is common across mid-ocean ridges and is found in magnesium- and iron-rich rocks, or mafic rocks.

Scientists are excited because they have no previous microbial data from this kind of deep, high-temperature vent.

Another newly discovered vent, Walsh, is located in a slightly different setting. The host rock is ultramafic — a rare rock that forms at very high temperatures.

The third site, Europa, named after the icy Jupiter moon that scientists believe may have life on it, is particularly unique. Though it is situated in an ultramafic environment like Walsh, it is a shallow vent with low temperatures. Scientists have only seen this type of vent once before at the "Lost City" site in the mid-Atlantic Ocean. 

Discovering these sites is only the first step. The scientists plan on returning to each of the vents to better examine the different types of communities living there — and ponder how life may have existed in distant lands (or waters) like Europa. 

Image: Woods Hole Oceanographic Institution