The Nitrate/Perchlorate Ratio on Mars as an Indicator for Habitability

Discovery of indigenous martian nitrogen in Mars surface materials has important implications for habitability and the potential development of a nitrogen cycle at some point in martian history. The Sample Analysis at Mars (SAM) instrument suite on the Mars Science Laboratory (MSL) Curiosity Rover detected evolved nitric oxide (NO) gas during pyrolysis of scooped aeolian sediments and drilled mudstone acquired in Gale Crater. The detection of NO suggests an indigenous source of fixed N, and may indicate a mineralogical sink for atmospheric N2 in the form of nitrate. The ratio of nitrate to oxychlorine species (e.g. perchlorate) may provide insight into the extent of development of a nitrogen cycle on Mars.