Nutrients of life found on Mars
Mars's life-friendly past just got friendlier. Using samples previously collected by the NASA rover Curiosity, scientists have discovered evidence of nitrates in Martian rock: nitrogen compounds that on Earth are a crucial source of nutrients for living things.
The findings, published in the journal Proceedings of the National Academy of Sciences, lend further support to the idea that the Red Planet could once have hosted habitable environments.
Although planetary scientists have been on the hunt for organic carbon — the type of carbon-containing molecules that could be used and produced by living things — nitrogen also plays an essential role in life as we know it, said lead author Jennifer Stern, a planetary geochemist at NASA Goddard Space Flight Center in Greenbelt, Md.
For example, nitrogen is a key component of nucleobases that make up RNA and DNA, and of amino acids, the building blocks of proteins.
"People want to follow the carbon, but in many ways nitrogen is just as important a nutrient for life," said Stern, a science team member for the Mars Science Laboratory mission, as Curiosity's mission is formally known. "Life runs on nitrogen as much as it runs on carbon."
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.