In Brief
Using samples previously collected by the NASA rover Curiosity, scientists discovered evidence of nitrates in Martian rock: nitrogen compounds that are a crucial source of nutrients for living things.
  • The scientists examined data from three samples processed by the Sample Analysis at Mars, or SAM, instrument, which is part of a formidable laboratory in Curiosity’s belly. They looked at samples pulled from three spots near its landing site: aeolian deposits from Rocknest and mudstone deposits from John Klein and Cumberland.
  • A fresh analysis of the nitrogen compounds in these rocks further strengthens that idea. The rock samples were cooked in SAM’s oven and the resulting gases were analyzed. The researchers found a significant amount of nitric oxide, a compound that, before it was cooked, probably came from nitrates.
  • Most nitrates on Earth are produced by living things, Stern said. But in the case of Mars, the team believes the nitrates were created during a “thermal shock,” such as a lightning strike or an asteroid impact. Among the next steps, she says, is to see whether whatever process that generated these nitrates is still happening on Mars.