The Curiosity Rover has discovered, according to new research, an unexpected seasonal change in oxygen on Mars.
Curiosity has been delivering some curious results for a long time. Following the localization of methane on the planet, investigations at its site in Gale C found regular changes in methane that can not be explained by the environmental factors already known to scientists. Now, oxygen from the air has combined with methane in the Mars mystery bucket.
Oxygen showed "significant seasonal and interannual variability, suggesting an unknown atmospheric or superficial process at work," the authors write in the article published today in the Journal of Geophysical Research.
Like Earth, Mars is tilted about its axis of rotation. This means that the northern and southern hemispheres experience seasons like the earth, summer, when the hemisphere on shows the sun, and winter when it points away from the sun. Scientists have used the Curiosity Sample Analysis tool at Mars (SAM) to monitor the abundance of various molecules in the planet's atmosphere and how they change with the seasons. Today they published the result of five Earth years (three Mars years).
The results for some elements were not particularly surprising: values and changes in the amount of argon gas were largely similar to those taken from the now deceased occasional rover . Curiosity has also not measured much nitrogen – on Earth, life interacts through a complex nitrogen cycle with the atmosphere and the soil. If such a cycle exists on Mars, it has no impact on the planet's atmospheric gas, the authors write.
But then … there's the oxygen. "The SAM measurements from [oxygen] in the Gale Crater do not show the annual stability or seasonal patterns predicted based on the known sources and sinks in the atmosphere," the authors wrote. There was much more oxygen than expected, and much less oxygen than e xpected during the winter of the emisphere (Cu riosity's summer).
Scientists tried to find an explanation . M Maybe the instrument was broken (it was not broken), or maybe the oxygen came from carbon dioxide or water that broke in the atmosphere. But that would mean that has much more water than the planet already has in its atmosphere, or carbon dioxide, according to a NASA publication decays too slowly to produce the oxygen signatures.
"The fact that oxygen behavior is not perfectly reproducible in every season suggests that this is not a problem related to atmospheric dynamics, it must be a chemical source and sink that we have "The first author of the study, Melissa Trainer, a planetary scientist at NASA's Goddard Space Flight Center, said in a press release.
Maybe the fluctuating oxygen has something to do with the fluctuating methane, who knows hopes other scientists can solve the puzzle.
Here at Gizmodo we do not say aliens, but … now …