Researchers have identified a ring of minerals around the largest basin in the northern hemisphere of Mars (which past research suggests held a large body of water). Phys.org says the research provides new clues on when life may have been possible on Mars — and how future astronauts could make oxygen: Manganese oxides and hydroxides (collectively written as manganese (hydr)oxides) can act as geological proxies for past oceans... The team involved in the new study analyzed short-wave infrared (SWIR) data from China's Zhurong rover, ESA's OMEGA orbiter and NASA's CRISM orbiter to identify and quantify manganese (hydr)oxides... The team says the placement of the ring indicates that the ring formed during the Hesperian epoch — a geologic period on Mars that occurred roughly 3.7 to 3.0 billion years ago. The Hesperian epoch marked the transition from the warmer, wetter, and volcanically active Martian world to a cold, dry, and dusty planet... [when "the potential for further prebiotic evolution on the surface was significantly reduced."] "This yields a final estimated duration of 0.8-1.5 million years for the presence of stable aqueous conditions in Utopia Planitia. This timescale significantly exceeds what is typically expected for transient surface water activity on Mars, suggesting that Utopia Planitia hosted a long-lived and evolving aquatic system during the Hesperian epoch, rather than a short-lived or rapidly evaporating water body," write the study authors. The researchers say that although this does not provide direct evidence of early life, it does suggest that Mars may have provided an environment conducive to initiating early forms of life. The timeline of the ocean matches the minimal timescale required for prebiotic chemistry, and also temporally overlaps with the period on Earth in which scientists believe the earliest forms of life first arose, approximately 3.4 billion years ago. The study authors also note that the conditions for life may have also extended into the next Amazonian period on Mars. They write, "If MnOx formation or redistribution occurred during the Amazonian, this would suggest that Mars may have maintained episodic or localized liquid water environments significantly later than traditionally assumed." Interestingly, the authors also bring up the potential for future human habitation on Mars. They suggest that oxygen can be produced by using the manganese (hydr)oxides for water-splitting reactions that generate oxygen through photocatalysis, potentially supporting human activities or even terraforming. Of course, this would be a long way off.Read more of this story at Slashdot.