Woods Hole, Mass. — How and where life began 3.5 billion years ago is still a mystery, but there are two things of which scientists are almost certain. First, for much of that time, life on Earth was almost exclusively microbial. Second, there must have been prebiotic precursor compounds such as amino acids, organic acids, and lipids available to jumpstart the formation of DNA, enzymes, and cell walls, and to set life on a path leading to the complex forms we see today.
An upcoming expedition aboard the US ocean drilling ship JOIDES Resolution co-led by Susan Q. Lang, a geochemist at the Woods Hole Oceanographic Institution (WHOI) and director of the National Ocean Science Accelerator Mass Spectrometry (NOSAMS) Facility, will attempt to shed new light on the processes that likely helped jumpstart the formation of life early in Earth’s history.
One place that may hold a window to those early, life-forming processes is the Lost City Hydrothermal Field (LCHF), which is famous for ghostly white vent chimneys the height of a house and alkaline vent fluids rich in hydrogen and methane—powerful sources of thermodynamic energy that may have fueled the formation of the first organic building blocks of life on Earth. Similar systems may also be present on “ocean worlds” such as Enceladus, one of the moons of Saturn that astrobiologists are looking to as a possible home for extra-terrestrial life.
“To understand the formation of life on Earth, we need understand the entire system that provided the energy to form and fuel early life,” said Lang. “Certain places on the seafloor let us see that system in full and to find and identify the prebiotic molecules that were necessary to create the first proto cells and then the first cells.”
Freider Klein, an associate scientist at WHOI, will also be on board as a Metamorphic Petrologist, looking for methane trapped in inclusions in the rocks.
The LCHF sits atop the Atlantis Massif at 30°N on the Mid-Atlantic Ridge. The Massif was formed by extensional faulting, bringing rocks from the lower crust and mantle up to the seafloor where they can be altered by seawater, producing the mineral serpentine and hydrogen. Previous ocean drilling and surveys of the Atlantis Massif has revealed, in addition to hydrogen, extensive generation of prebiotic compounds including organic acids, short-chain hydrocarbons, methane, and amino acids.
These compounds may be feeding ancient forms of microbial life living in high temperature, high pressure, and extreme alkalinity inside the LCHF chimneys and even far below the seafloor. IODP Expedition 399 aims to discover where and how hydrogen, methane, and more complex compounds are being generated within the Massif, how these chemicals get into the hydrothermal vent fluids, and how the energy and nutrients needed to support microbial communities originate.
“The Atlantis Massif has an important story to tell,” said Lang. “It’s not easy to collect samples from places like this, but doing so gives us the opportunity to fill in missing pieces to the story of life on Earth and to set the stage for the discovery of life beyond our planet.”
The expedition departs Ponta Delgada, Portugal, on April 12 and is funded by the National Science Foundation OCE-1450528, as part of the Integrated Ocean Discovery Program (IODP). More information on the expedition, IODP, and JOIDES Resolution is available online.
About Woods Hole Oceanographic Institution
The Woods Hole Oceanographic Institution (WHOI) is a private, non-profit organization on Cape Cod, Massachusetts, dedicated to marine research, engineering, and higher education. Established in 1930, its primary mission is to understand the ocean and its interaction with the Earth as a whole, and to communicate an understanding of the ocean’s role in the changing global environment. WHOI’s pioneering discoveries stem from an ideal combination of science and engineering—one that has made it one of the most trusted and technically advanced leaders in basic and applied ocean research and exploration anywhere. WHOI is known for its multidisciplinary approach, superior ship operations, and unparalleled deep-sea robotics capabilities. We play a leading role in ocean observation and operate the most extensive suite of data-gathering platforms in the world. Top scientists, engineers, and students collaborate on more than 800 concurrent projects worldwide—both above and below the waves—pushing the boundaries of knowledge and possibility. For more information, please visit www.whoi.edu.