NASA's Mars Curiosity Rover has detected rising and falling oxygen levels on the Red Planet that appear to fluctuate seasonally, Yahoo News reports. What that means, if indeed it means anything, remains to be seen.
For decades, the space-exploration community has been sending spacecraft to Mars to try to suss out its mysteries. At this stage of the game, the craft that are on the surface and orbiting the planet are looking for one thing -- evidence of life, either currently living or long dead and fossilized. While that's not the only thing they're looking for, it's certainly one of their main goals.
Finding evidence of life on Mars isn't easy, however. Short of observing a living or fossilized organism directly, which is seemingly impossible, the best scientists can do is look for chemical and elemental markers of the existence of life. This largely concerns looking for chemicals or elements that would be present in order to sustain life as well as those that would generate from decaying organisms.
As it turns out, the Curiosity Rover's instruments have detected one such element -- oxygen. Necessary to sustain life as it is currently known, the existence of the element on Mars could be indicative of organisms there. However, its presence is far from conclusive, especially as the oxygen levels appear to fluctuate seasonally, rising as much as 30 percent in the Martian spring and summer.
Another elemental marker that could possibly indicate life on Mars -- methane -- has also been found on the planet. As reported at the time by The Inquisitr, in June the Curiosity's instruments detected the presence of the gas on the planet, possibly indicating an "organic source," as methane is a bi-product of organic decomposition.
Curiously, the Martian methane, like the oxygen, also tends to fluctuate seasonally. Sometimes it fluctuates in tandem with the oxygen levels, rising as much as 60 percent in the summer, but it also frequently rises and drops dramatically for no discernible reason.
Scientists are struggling to figure out what this all means. It could mean everything, or it could mean nothing.
"We're struggling to explain this. 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," says Melissa Trainer of NASA's Goddard Space Flight Center.
Whether or not there is, or ever was, life on Mars has tantalized scientists for centuries. Mars is almost certainly inhospitable to life. It has extreme temperatures, a thin atmosphere consisting mostly of carbon dioxide, a lack of protection from radiation, and a host of other reasons that would make the formation of life on the planet virtually impossible. However, there may yet be something there. If there is, it almost certainly would be composed of primitive, unicellular organisms, lurking below the surface.