Posted on Wednesday, 13 November, 2019
Something strange is going on with the oxygen concentrations on Mars. Image Credit: NASA
The long-running mystery of methane on Mars has now been joined by another perplexing enigma - oxygen.
NASA's Curiosity rover has made some fascinating discoveries during its exploration of Gale Crater and this latest one is no exception.
Following the release of five years' worth of data from the rover's Sample Analysis at Mars (SAM) portable chemistry lab, it has been revealed that the oxygen in the planet's atmosphere exhibits anomalous seasonal variations thought to be caused by some unknown chemical process.
Like the Earth, Mars is tilted on its axis of rotation, meaning that it, too, experiences seasons.
Curiosity's SAM instrument has been monitoring the atmospheric composition from season to season, recording the various concentrations of gases over the course of several years.
While it found that nitrogen and argon follow a predictable seasonal pattern however, it turns out that oxygen does not - something seems to be regularly producing it and then taking it away again.
"The first time we saw that, it was just mind boggling," said study co-author Prof Sushil Atreya.
As things stand, nobody is quite sure what the explanation for this could be.
"We're struggling to explain this," said NASA's Melissa Trainer. "The fact that the oxygen behavior isn't perfectly repeatable every season makes us think that it's not an issue that has to do with atmospheric dynamics. It has to be some chemical source and sink that we can't yet account for."
The search for answers continues.
Thanks to: https://www.unexplained-mysteries.com