Overview

• Researchers directly linked microbial activity to an impact-generated hydrothermal system by combining isotopic biosignatures with radioisotopic dating.
• Substantially 34S-depleted pyrite formed at 47.0 ± 7.1 °C and 73.6 ± 2.2 million years ago indicates microbial sulfate reduction about five million years after the impact.
• Later mineral phases, including biosignature-bearing calcite, record methane consumption and production more than 10 million years post-impact.
• The results demonstrate that impact craters can serve as long-lived subsurface habitats as they cool into habitable temperature ranges.
• The peer-reviewed Nature Communications study by Gustafsson et al. provides methods that can be applied to other Earth craters and to planetary sample-return analyses.