Until recently, scientists believed that nitrous oxide (N2O) could be created only by the microbial breakdown of nitrogen in soil. But this May, researchers published findings that the gas is also produced by chemical reactions in an Antarctic pond. The discovery could help scientists understand the nitrogen cycle on Mars.

Vladimir Samarkin, a biogeochemist at the University of Georgia, and his colleagues found that when nitrites in the Don Juan Pond come in contact with certain types of iron-rich rock present there, they react to release N2O. Because the pond’s cold, salty, lifeless conditions are similar to those on Mars, it could help to explain how nitrogen, a key element for life, fluxes between the Red Planet’s soil and its atmosphere.