Scientists at NASA measured seasonal changes in gas air Mars, specifically the crater Gale, and have discovered that oxygen is behaving in a way that can not be explained by any chemical process known.
The Gale crater is one of the most promising places on Mars in terms of possibilities of finding conditions for life, since it has, among other features, traces of an ancient lake.
For three years, the Curiosity rover sent by NASA analyzed the composition of air in the crater.
Through their Sample Analysis instrument on Mars (SAM), they discovered that there was 95% carbon dioxide (CO2), 2.6% molecular nitrogen (N2), 1.9% argon (Ar), 0.16% molecular oxygen (O2), and 0.06% carbon monoxide (CO).
By measuring the relationship of gases with CO2, which predominates in the Martian atmosphere, they found that argon and nitrogen maintained a stable concentration throughout the year.
However, oxygen increased up to 30% in summer and then fell back to the levels predicted for autumn. This began to repeat every year.
In addition, the amount of oxygen increase varied, which implies that something is producing it and then withdraws it.
“The first time we saw that, it was amazing,” said Sushil Atreya of the University of Michigan, who is co-author of the study published this November 12 in the Journal of Geophysical Research: Planets.
When examining the data obtained, the scientists estimated that it would take five times more water on Mars to produce the additional oxygen they found.
As for the sudden decrease in gas, the cause should be solar radiation; but they concluded that it would take at least 10 years for oxygen to disappear through this process.
“We are struggling to explain this,” said Melissa Trainer, a planetary scientist at NASA’s Goddard Space Flight Center, who led the research.
“The fact that oxygen behavior is not perfectly repeatable every season makes us think that it is not a problem that has to do with atmospheric dynamics. It has to be a chemical source and a sink that we still can’t explain.”
Before, they had detected that methane increased by 60% in the summer months for unexplained reasons.
At the time, the discovery of methane was very important due to its possible relationship with ancient life on the red planet.
“We are beginning to see this tempting correlation between methane and oxygen for a good part of the year on Mars,” Atreya said.
“I think there is something about that. I just don’t have the answers yet. No one has them.”