资源环境科技发展态势分析平台

The presence of biogenic gases such as oxygen, methane, and nitrous oxide (N₂O) in the atmospheres of extraterrestrial bodies has been postulated as a biosignature of life. Abiotic N₂O production was documented recently in Don Juan Pond, Antarctica, a cold, hypersaline Mars analog environment. Here we quantify the temperature-driven kinetics of abiotic N₂O production and combine this with stable isotope labeling to demonstrate that N₂O is produced from Don Juan Pond sediment and brine at Mars-analog temperatures down to at least –40°C. Further, we show that at any given temperature, N₂O production is controlled by the availability of reduced Fe-bearing minerals rather than nitrate. We conclude that abiotic N₂O production is possible on Mars and on other extraterrestrial bodies and exoplanets. Thus, the presence of atmospheric N₂O on these bodies should not be taken by itself as an indicator of microbial life.