The Mars Curiosity rover traces nitrates on Mars, which scientists suggest is an ingredient of life of the Red Planet.
Scientists explain that nitrates are nitrogen compounds, which serves as a key nutrients component for living organisms on Earth. The latest finding backs the theory that the currently barren planet may have supported some form of life previously.
Nitrogen plays a significant role in living things but planetary scientists are in the look-out for organic carbon, which is a kind of carbon that contains molecules that may have been produced or used by living organisms.
"People want to follow the carbon, but in many ways nitrogen is just as important a nutrient for life," says Jennifer Stern, who is a planetary geochemist at NASA Goddard Space Flight Center in Greenbelt. "Life runs on nitrogen as much as it runs on carbon."
Stern points out that nitrogen is an ingredient for nucleobases, which makes up DNA and RNA. Nitrogen is also a key component of amino acids, which are the building blocks of proteins.
Scientists explain that they examined rock and soil samples from three sites on Mars: Rocknest, Cumberland and John Klein. Curiosity has been drilling at various sites on the Mars and also examining the samples through its on-board laboratory.
The instrument in Curiosity's on-board lab called Sample Analysis at Mars, or SAM, cooked the samples and analyzed the gases produced. The scientists found significant levels of nitric oxide, which is estimated to have come from nitrates.
"What we're detecting is nitric oxide, but we know from lab experiments that when we heat up nitrates, they break down in a predictable way. And that's why we think these are nitrates," added Stern.
The researchers suggest that they had to ensure that any contamination from the Curiosity rover itself was subtracted so that the results did not give false signals. The samples from all three sites had considerable amount of nitrate; however, less than what is found in some exceptionally dry places on the Earth like South America's Atacama Desert.
Scientists also explain living things on Earth are responsible for producing most of the planet's nitrates. However, thermal shock on Mars such as asteroid impact or lighting strike may be responsible for creating some nitrates on the Red Planet.
Stern reveals that they are trying to understand if such process of producing nitrates is still occurring on Mars, or it happened on the planet long time back in the presence of a different environment.
The study has been published in the journal PNAS.
