Astrobiologists at NASA have successfully recreated the conditions of the primordial ocean where life on Earth began some 4 billion years ago.
The team from the Jet Propulsion Laboratory in Pasadena, California recreated hydrothermal vents, openings in the ocean floor where heated water and material from within the crust spew, to understand the building blocks of life.
The study was done to understand how life formed in the early years of planet Earth. This will allow scientists to one day identify areas in the cosmos where extraterrestrial organisms might also blossom and thrive.
Investigating How Life On Earth Began
The researchers recreated the conditions of the primordial ocean by filling a laboratory beaker with the same materials that were present when life began on Earth billions of years ago. They mixed water, minerals, as well as pyruvate and ammonia — molecules usually found near hydrothermal vents and are precursors for the formation of the building blocks of life.
They also heated the beakers to 158 degrees Fahrenheit, adjusted the pH to mimic alkaline environments, decreased oxygen, and used a mineral called iron hydroxide, or green rust, which was abundant in the early years of Earth.
During the experiment, the researchers discovered that when a small amount of oxygen was introduced to green rust, it caused a reaction that led to the formation of the amino acid alanine and alpha hydroxy acid lactate. While the team did not produce life, they believe that the molecules produced from the artificial ocean might recombine and eventually allow life to flourish.
"We've shown that in geological conditions similar to early Earth, and maybe to other planets, we can form amino acids and alpha hydroxy acids from a simple reaction under mild conditions that would have existed on the seafloor," stated Laurie Barge, an astrobiologist who co-authored the study.
Search For Extraterrestrial Life
Scientists believe that the same conditions that led to the creation of life on Earth might also allow the formation of life elsewhere in the universe.
"If we have these hydrothermal vents here on Earth, possibly similar reactions could occur on other planets," added Erika Flores from JPL, also an author of the study.
The findings of the research can inform future interstellar missions and help identify where to look for signs of extraterrestrial life. The moons Europa (Jupiter) and Enceladus (Saturn), for example, are ocean worlds where hydrothermal vents could exist under their icy crusts.
Details of the experiment appear in the Proceedings of the National Academy of Sciences.