NASA Research Shows Early Life Relied on Rare Metal

The new study indicates that life used molybdenum as far back as 3.3 to 3.7 billion years ago, long before levels of molybdenum in the oceans increased to modern levels. Other events in Earth’s history are marked for context. NASA NASA-funded scientists have discovered that life on Earth over 3 billion years ago relied on the metal molybdenum, which was incredibly scarce in the environment at the time. The study, published in Nature Communications on Tuesday, is the first to show that molybdenum was used by ancient life this far back in our planet’s history. On Earth today, molybdenum helps speed up vital biochemical reactions in cells. The metal is a component of essential enzymes that drive several major biological reactions in organisms. This is not only important for the individual organisms, but also biogeochemical cycles, such as the nitrogen cycle, which affect our entire planet. Without molybdenum, those important reactions could still happen in nature, but they would be too slow to sustain life. “Molybdenum sits at the catalytic center of enzymes that run major carbon, nitrogen, and sulfur reactions,” explained Betül Kaçar, head of the Kaçar Lab at the University of Wisconsin-Madison and senior author on the study. Kaçar leads MUSE, a NASA Interdisciplinary Consortia for Astrobiology Research (ICAR) at UW-Madison. “Asking when life began using molybdenum is really asking when some of the most consequential metabolic strategies became possible,” said Kaçar. Molybdenum through history Molybdenum is now relatively common in the environment, and its scarcity is no longer a problem for life. But that wasn’t always the case. Geological evidence shows that only trace amounts of molybdenum were present in Earth’s oceans billions of years ago. Levels increased around the time that microorganisms began to use photosynthesis, which eventually led to a drama