According to slash Gear, a foreign media outlet, some of the reasons are causing a surge in oxygen levels in the Martian atmosphere. Despite the best efforts of the Curiosity rover and NASA’s team to filter its data back to Earth, scientists don’t know what caused it. Although it is well known that the Red Planet does not support human life in its current state, this does not mean that it has no oxygen in its atmosphere at all.
In fact, 0.16% of the Martian atmosphere is molecular oxygen. Most are carbon dioxide, accounting for 95 per cent, while molecular nitrogen is 2.6 per cent, argon is 1.9 per cent and carbon monoxide is 0.06 per cent.
Since landing on Mars six years ago, Curiosity has been using a special tool, the Mars Sample Analysis (SAM) instrument, to track the balance of gaseous molecules. The scientists studied the data returned by the rover, which is equivalent to three years of seasonal variation. They are now surprised by the constant fluctuations in oxygen levels.
Like Earth, changes in air pressure on Mars change their atmosphere. For example, in the Martian winter, carbon dioxide freezes at the poles of Mars: when the air is redistributed to balance the air, it lowers the overall air pressure. In spring and summer, when carbon dioxide evaporates again, the situation reverses.
What scientists expect to see during these transitions is a consistent and predictable change in the proportion of each gas involved. Although this is true for nitrogen and argon, oxygen has been shown to be outliers relative to carbon dioxide levels.
In spring and summer, the amount of oxygen in the Martian air mysteriously rises by 30%. In the autumn, it will again drop to normal forecast levels.
“This pattern repeats every spring, although the amount of oxygen added to the atmosphere varies, suggesting that something is being produced and then taken away,” said Lonnie Shekhtman of NASA’s Goddard Space Flight Center. “
After examining SAM’s potential misreadings, NASA’s team tried to come up with potential theories to explain the dramatic shift. There is not enough water in the air to break down and release oxygen, and carbon dioxide breaks down too slowly to observe changes in levels. Similarly, solar radiation is too slow to break down oxygen into atoms and blow it into space.
Happily, the interaction between oxygen changes and seasonal changes in methane levels has been observed, and scientists are theoretically linking the two. “The fact that oxygen behavior in each season is not completely repeatable makes us think it has nothing to do with atmospheric dynamics,” explains Melissa Trainer, a planetary scientist at the Goddard Space Flight Center and lead of the new study. This must be some kind of chemical source that we can’t explain. “
However, the exact link may be uncertain. Shekhtman notes that biological activity is of course a source of methane and oxygen, but there is still no “compelling evidence” of any biological activity on Mars. At the same time, Curiosity lacks any specific means to determine whether the gas is from biological or geological sources.
Without these tools, all the team can do is continue to measure the changes in levels and explain in theory what might cause them. The new Mars 2020 rover is expected to travel to the Red Planet for scientific exploration with Curiosity until NASA’s next mission to Mars next year. The European Space Agency will also launch the ExoMars rover, while China plans to launch it in 2020.