This is a big day for little Mars rovers. First, 11-year-old Opportunity crossed the finish line at the first off-world marathon. Then, her younger sister, Curiosity, found nitrogen on Mars, in a form that could be used by living creatures, in dust and rock samples collected at the site of an ancient lakebed. This seems to confirm scientists’ belief that life existed in ancient times on Mars.
The discovery was presented in a paper published in the on March 23 online in the Proceedings of the National Academy of Science March 23. The lead author of the paper, Jennifer Stern of the Goddard Space Flight Center says, “Finding a biochemically accessible form of nitrogen is more support for the ancient Martian environment at Gale Crater being habitable.”
This evidence was found in the rock samples collected and analyzed by the Sample Analysis at Mars (SAM) instruments on board the rover. The rovers are essentially mobile geological laboratories. The rock samples were first heated, then the gases released during the hearing process were analyzed by two instruments – a mass spectrometer and a gas chromatograph – to identify component elements.
The samples were consisted of materials scooped up from wind blown sand and dust, and drilled from mudstone at two sites in Yellowknife Bay. Yellowknife Bay may be the site of an ancient lakebed. It was considered by mission scientists to have been a habitable environment, with fresh water, carbon and other chemical elements needed for life, and sources of energy that could be used by simple organisms. The fact that nitrates – the likely source for the nitrogen – were also found in the samples of wind blown dust suggests that nitrogen might be found at many other locations as well.
Nitrogen is essential to all known forms of life as it forms one of basic building blocks of DNA and RNA molecules, and proteins.
Curiosity’s mission is to discover if Mars ever supported simple life forms such as microbes, and if it is habitable. The rover carries the most advanced instruments ever went to Mars, developed through collaborations between NASA, the European Space Agency, and private industry. Curiosity landed on Mars in 2012 and represents the beginning of the next generation of Mars exploration.
