A new study reveals asteroid impacts on ancient Mars could have produced key ingredients for life if the Martian atmosphere was rich in hydrogen. An early hydrogen-rich atmosphere on Mars could also explain how the planet remained habitable after its atmosphere thinned. The study used data from NASA’s Curiosity rover on Mars and was conducted by researchers on Curiosity’s Sample Analysis at Mars (SAM) instrument team and international colleagues.
These key ingredients are nitrites (NO2) and nitrates (NO3), fixed forms of nitrogen that are important for the establishment and sustainability of life as we know it. Curiosity discovered them in soil and rock samples it took as it traversed within Gale Crater, the site of ancient lakes and groundwater systems on Mars.
To understand how fixed nitrogen may have been deposited in the crater, researchers needed to recreate the early Martian atmosphere here on Earth. The study, led by Dr. Rafael Navarro-González and his team of scientists at the Institute of Nuclear Sciences of the National Autonomous University of Mexico in Mexico City, used a combination of theoretical models and experimental data to investigate the role hydrogen plays in altering nitrogen into nitrites and nitrates using energy from asteroid impacts. The paper was published in January in the Journal of Geophysical Researc: Planets.
In the lab, the group used infrared laser beam pulses to simulate the high-energy shockwaves created by asteroids slamming into the atmosphere. The pulses were focused into a flask containing mixtures of hydrogen, nitrogen and carbon dioxide gases, representing the early Martian atmosphere. After the laser blasts, the resulting concoction was analyzed to determine the amount of nitrates formed. The results were surprising, to say the least… [More at links]