Bubbling Organics in an Ocean Vent Simulator
Scientists with the NASA Astrobiology Institute's JPL Icy Worlds team have built this series of glass tubes, thin barrels and valves with a laser and a detector system. The set-up mimics the conditions at hydrothermal vents at the bottom of Earth's ocean and also detects compounds coming out of it. They want to see if sending these two liquids through a sample of rock that simulates ancient volcanic ocean crust can lead to the formation of simple organic molecules such as ethane and methane, and amino acids, biologically important organic molecules. Scientists have long considered these compounds the precursor ingredients for what later led to chains of RNA, DNA and microbes.
A group of researchers at JPL, including senior geologist Mike Russell, Icy Worlds Principal Investigator Isik Kanik, postdoctoral fellow Laurie Barge, graduate student Lauren White and visiting scholar Takazo Shibuya, have been testing this "origin of life" theory in a refrigerator-sized apparatus at an annex to the Microdevices Laboratory at JPL.
"What we're trying to do is to climb down and create the conditions for the very first steps to the beginning of life as we know it," said Russell, who is leading the experiment. "That's the hard part."
The experiment is a key component of the Icy Worlds project, which is managed at JPL for the NASA Astrobiology Institute, based at NASA's Ames Research Center, Moffett Field, Calif. The project aims to learn more about potentially habitable environments such as Mars, as well as liquid water environments on icy bodies like Saturn's moon Enceladus and Jupiter's moon Europa. "If this ocean experiment is successful, scientists would have a better handle on where to look for the building blocks of life on Earth and beyond, and what signatures we should be looking for of life and of habitable environments in the solar system," said Kanik.
This experiment has its roots in a theory from Russell in 1989 that moderately warm, alkaline hydrothermal vents at the bottom of the ocean could have hatched life about 4 billion years ago. The ancient ocean at these vents contains carbon dioxide, which provides the supply of carbon that could be reassembled into organic molecules. In 2000, such a vent was discovered at the bottom of the middle of the Atlantic Ocean. The vent later showed signs of generating simple organic molecules.
The experiment runs as close a simulation to the conditions of these hydrothermal vents as is feasible in a lab setting - at 100 times the pressure of Earth's surface and at about 90 degrees Celsius (about 200 degrees Fahrenheit). Scientists are alternating the fluid flows to simulate the circulation at the ocean floor.