World-first deep-ocean landers to hunt down origins of dark oxygen

Researchers have developed two pioneering deep-ocean landers, named Alisa and Kaia, to investigate the mysterious production of "dark oxygen"—oxygen generated without sunlight—found about 13,000 feet below the ocean surface in the Clarion-Clipperton Zone (CCZ) of the Pacific Ocean. This discovery challenges the long-held belief that oxygen production depends on sunlight. The landers, capable of withstanding pressures 1,200 times that at the surface, will explore whether polymetallic nodules (also called manganese nodules), which contain metals like nickel, cobalt, and manganese, act as natural batteries by splitting seawater into oxygen and hydrogen through electrochemical or biological processes. Led by The Nippon Foundation’s Dark Oxygen Research Initiative (DORI), the three-year project brings together experts including Andrew Sweetman, who first identified dark oxygen in 2013, Jeffrey Marlow, a geologist with Mars-rover experience, and chemist Franz M. Geiger.