Prevalent assumptions that the environment on Mars could not support aerobic organisms were shattered this past Monday when researchers from the NASA Jet Propulsion Laboratory (JPL) in California revealed that they had discovered oxygen in the planet’s salt-water reservoirs.
In certain specific locations, there was even enough oxygen to sustain simple multicellular animals like sponges.
“We discovered that brines” — water with high concentrations of salt — “on Mars can contain enough oxygen for microbes to breathe,” said lead author Vlada Stamenkovic, a theoretical physicist at JPL. “This fully revolutionises our understanding of the potential for life on Mars, today and in the past” he added.
Since only 0.14 percent of Mars’s atmosphere is oxygen, it had been assumed that even microbial life was not possible on the planet. In comparison, Earth’s atmosphere is 21 percent oxygen.
It should be noted however, there are microbes on Earth at the bottom of the ocean that thrive in the absence of oxygen. For this reason, when studying the potential for life on Mars, scientists had prioritised looking for anaerobic life.
Researchers’ attention had initially been attracted when NASA’s Curiosity Mars rover discovered manganese oxide, a compound that can only be produced in the presence of significant amounts of oxygen.
The Curiosity rover also established the presence of brine deposits with significant variations in the elements they contained. Water with high salt content is hospitable to halophilic microbes because the presence of salt allows water to remain liquid at very low temperatures. Temperatures on Mars can vary between minus 195 and 20 degrees celsius.
The researchers then devised a model to describe how oxygen dissolved in the Martian brine deposits, and a second model to establish temperature changes on the planet over the last 20 million years and predicted changes that will take place over the next 10 million years.
Taken together, the calculations showed which areas of the Red Planet have the greatest concentration of oxygen. This data could then be used to determine the placement of probes meant to seek out aerobic microbial life.
“Our results do not imply that there is life on Mars,” Stamenkovic cautioned. “But they show that the Martian habitability is affected by the potential of dissolved oxygen.”