According to foreign media reports, scientists have found something strange about the oxygen in the atmosphere above Mars’ Gaelic crater: oxygen levels fluctuate dramatically with the seasons, and this mysterious periodic change in oxygen cannot be explained by any known chemical reaction. The Gaelic crater, about 154 kilometers in diameter, was formed by a comet impact between 3.5 billion and 3.8 billion years ago.
NASA’s Curiosity Mars rover has been exploring Mount Sharp since it landed in the middle of the crater in 2012. For the past three years on Mars (equivalent to more than five Earth years), Curiosity has been using an instrument called the Mars Sample Analyzer (SAM) to analyze the atmosphere over The Gaelic crater. The instrument confirmed that 95 percent of the Martian atmosphere is carbon dioxide, while the remaining 5 percent is a combination of nitrogen, oxygen, argon and carbon monoxide. The Mars Sample Analyzer also found that carbon dioxide gas over the Poles freezes during the winter months, and the air pressure on Mars as a whole drops. And when the weather warms and the frozen carbon dioxide is re-reduced to gas, the air pressure rises again. The concentration of argon and nitrogen also increases and decreases regularly, depending on the amount of carbon dioxide in the atmosphere.
But when the instrument analyzed oxygen levels above Gale’s ring, the results were confusing: oxygen levels rose far more than expected, rising by up to 30 per cent from the baseline levels for the spring and summer seasons, and by winter, oxygen levels would be much lower than expected.
“We’re trying to explain this,” said Melissa Trainer, a planetary scientist at NASA’s Goddard Space Flight Center. These oxygens do not exhibit a perfect pattern of seasonal variation, so we think this may have nothing to do with atmospheric dynamics or any physical processes that occur in the atmosphere. On the contrary, the source of this phenomenon must be some kind of chemical reaction that we have not yet figured out. “
Not only that, but the change in methane levels above the Gale impact crater is also a mystery. The Mars Sample Analyzer has previously found that, for some unknown reason, methane in the region sometimes increases by about 60 percent in the summer, and then suddenly drops rapidly at a random point in time.
Scientists believe there may be a link between methane and oxygen on Mars, but no one knows exactly what that association is. Oxygen and methane can be produced through biological and geological pathways, such as water and rocks, and scientists don’t know exactly which way to generate these excess gases. But alien enthusiasts may be disappointed, as the team said in a statement that the excess oxygen and methane may have been produced by geological pathways, most likely buried in Martian soil. But even then, scientists don’t know exactly what kind of ingredient in the soil releases so much oxygen.