Jupiter’s moon Europa may have less oxygen than expected, a finding that might put a damper on life

New research based on data collected by NASA’s Juno spacecraft suggests there's less oxygen on the icy surface of Jupiter's moon Europa than thought. Even with little or no oxygen, microbes might still be bustling around in the ocean believed to exist miles (kilometers) beneath Europa’s frozen crust. The study was published on Mar. 4 in Nature Astronomy. The new findings are based on data collected by NASA’s Juno spacecraft during a particularly close flyby of Europa in 2022—a distance of just 219 miles (353 kilometers). A U.S.-European team calculated that between 13 pounds and 39 pounds (6 kilograms and 18 kilograms) of oxygen are produced every second at Europa’s surface. Previous estimates were much higher so the new numbers provide “a narrower range to support habitability,” the researchers wrote. This oxygen is formed, along with hydrogen, as Jupiter’s radiation blasts Europa’s global shell of frozen water. Lead author James Szalay of Princeton University says Juno’s flyby was the first time a spacecraft “directly sniffed” Europa’s surroundings. "We revealed a key piece in the story of Europa's interaction with its environment, how much oxygen gets produced in the ice. Before Juno flew by Europa, there are very broad constraints on how much that was, anywhere from a few kilograms per second to over 1000. We've constrained it to a very narrow range on the order of 12kg per second," he says. "We determine the total amount of oxygen produced in the ice. And this is a really important quantity because that tells us how much oxygen can leave the surface to the atmosphere, how much gets stuck in the ice, and how much goes to the ocean. All of that is... the sum of that has to be the total amount that we found in the current epoch. And so in the sense, our derived amount of oxygen that we found is an upper limit to the total amount that could make its way to the ocean in the current time frame as a source of potential metabolic energy for life," explains Szalay. This article was provided by The Associated Press.