Oxygen and life on Earth are deeply intertwined. With oxygen making up about 21% of our atmosphere, it plays a vital role in sustaining life. For a long time, scientists believed that the rise in atmospheric oxygen was primarily driven by photosynthesis, especially from cyanobacteria. But new findings from the deep ocean are challenging that theory.
In the Clarion-Clipperton Zone (CCZ), located 4,000 meters beneath the surface of the Pacific Ocean, researchers have discovered a surprising source of oxygen—known as "dark oxygen." Unlike traditional oxygen production, this form doesn’t rely on sunlight or photosynthesis. Instead, it’s generated through a chemical reaction involving polymetallic nodules found on the seafloor. These nodules function like natural "geobatteries," creating voltage that splits seawater into hydrogen and oxygen.
This breakthrough reshapes our understanding of how oxygen—and by extension, aerobic life—may have originated. It also raises critical questions about the environmental impact of deep-sea mining in such sensitive regions. Moreover, the discovery supports the idea that wherever there is water, oxygen could potentially be present too—an insight that could prove invaluable in the search for life and future colonization efforts beyond Earth.
Overall, the findings underscore the intricate connection between water and oxygen and open new doors in both Earth sciences and space exploration.