The secret to life on Earth could be deeper than we thought.
Scientists have discovered that metal nodules on the ocean floor are producing oxygen in total darkness without any aid from living organisms, which could upend our understanding of the origin of life.
This eye-opening revelation was revealed in a groundbreaking study in the journal Nature Geoscience.
“I think we need to revisit questions like: where could aerobic life (life that requires oxygen) have begun?” the study’s lead author Andrew Sweetman, professor of seafloor ecology at the Scottish Association for Marine Science (SAMS) in Oban, UK, said in a statement.
Sweetman and his team discovered the phenomenon, dubbed “dark oxygen,” accidentally while sampling the seabed over 13,000 feet down in a 1.7 million square mile swath of seafloor located between Mexico in Hawaii.
They had originally set out to assess the impacts of mining the aforementioned metal nuggets, including cobalt, nickel and rare earth metals such as cerium (an essential component of certain electronics).
However, while scanning the seabed, the sensors detected mysterious oxygen emissions originating in the area.
This phenomenon seemed impossible given that the area was too deep for light to penetrate and therefore foster photosynthesis — the process by which plants and other organisms convert water and carbon dioxide into oxygen and energy.
However, this discovery marked the first time that scientists had observed oxygen being generated without the involvement of organisms.
Sweetman was so flabbergasted by the finding that he “initially thought the sensors were faulty.”
“Every study ever done in the deep sea has only seen oxygen being consumed rather than produced,” said the shocked scientist, who sent the equipment back to the manufacturer for testing, only to have them confirm that it was working fine.
Sweetman determined through subsequent experiments that the metallic nodules create this “dark oxygen” through a process called seawater electrolysis.
This occurs when seawater divides into oxygen and hydrogen while in the proximity of an electric charge, which in this case, is provided by the highly-charged metal ovals like an aquatic battery.
“Only a voltage of 1.5 V is needed for seawater electrolysis to occur – the same voltage as a typical AA battery,” the authors wrote in the statement. “The team analyzed multiple nodules and recorded readings of up to 0.95 volts on the surfaces of some, meaning that significant voltages can occur when the nodules are clustered together.”
In other words, nature is so metal.
Ultimately, Sweetman believes that discovery could challenge our perception of how life on Earth began approximately 3.7 billion years ago.
“For aerobic life to begin on the planet, there has to be oxygen and our understanding has been that Earth’s oxygen supply began with photosynthetic organisms,” he said. “But we now know that there is oxygen produced in the deep sea, where there is no light.”
This revelation also sparks concerns about the potential environmental ramifications of harvesting the metallic lumps, which could provide a crucial source of oxygen for these deep-sea habitats.
