Scientists have discovered evidence of nitrate in Mars rocks found by NASA's Curiosity rover, an exciting development that researchers say makes it more likely that life once thrived on the red planet. The findings support the notion that nitrogen, not carbon, may have sustained bacterial organisms in the past.

Nitrogen plays an important part in supporting life as humans know it, acting as a component in the development of DNA, RNA and amino acids, which act as the building blocks of protein. Now, NASA has found it in rocks collected from three different regions of Mars. The finds were first published in the journal Proceedings of the National Academy of Sciences and highlighted by the Los Angeles Times Monday.

“People want to follow the carbon, but in many ways nitrogen is just as important a nutrient for life,” Jennifer Stern, a planetary geochemist at NASA and a member of the Curiosity team, told the newspaper. “Life runs on nitrogen as much as it runs on carbon.”

The rocks were collected by Curiosity and examined within the laboratory section of the rover in what's known as the Sample Analysis at Mars, or SAM, instrument. Scientists scraped off possible contamination and heated the rocks, finding that they broke down in a way that nitrate also breaks down. Nitrate molecules are so important because they're easy for living things to obtain and then use.

“We're going to try to understand whether this process is still happening to day at all,” Stern told the Times of the ongoing Mars examinations, “or whether this all happened in the past in a different Mars, in a different climate regime, in a different atmosphere.”