Big news from Mars today: NASA's Curiosity rover found ancient traces of organic matter embedded in Martian rocks and detected a "seasonal variation" in atmospheric methane on the Red Planet - an annual pulse of the gas, nearly as if something out there were breathing.
The case for past habitability on the Red Planet is bolstered by the discovery of preserved organic compounds revealed today, as they are as old as the around 3.5 billion year old sedimentary rocks in which they were found.
NASA says, 'The media and public are invited to ask questions during a live discussion at 2 p.m. EDT Thursday, June 7, on new science results from NASA's Mars Curiosity rover'. That leaves open the possibility that microorganisms once populated the red planet - and still might. That's not to say there are no non-biological sources, but on our world they're swamped by cow farts and belching bacteria.
The scientists hope to find better preserved organic compounds with Curiosity or other rovers that would allow them to check for chemical signatures of life. More powerful spacecraft are needed to prove whether life ever existed on Mars.
Xbox 360 E3 Week Sale
Microsoft says that more than 300 games will be on sale, with some titles starting as low as $19.99. It will also be offering some Season Passes and DLC for 50 percent or more off the standard price.
In four locations, including the spot nicknamed Mojave (pictured here), the Curiosity rover discovered thiophenes (molecules that include a ring of carbon and sulphur atoms) and other substances that on Earth can be linked to biological activity. The Wikipedia article on "organic matter" makes the point: "Organic molecules can also be made by chemical reactions that don't involve life". The crystals may have obtained methane from ancient forms of life.
These chemicals might not mean a great deal to most of us, but to areologists (that's Martian geologists) it's an indication that the organic chemistry in Martian mudstone is extremely similar to our own. "Curiosity has shown that Gale Crater was habitable around 3.5 billion years ago, with conditions comparable to those on the early Earth, where life evolved around that time". That doesn't necessarily mean that Curiosity discovered signs of past life. On Mars, where we only have a few molecules from a remote probe, this stuff is light years away from being conclusive.
Questions remain, however, as to how the organic material was formed. "While we don't know the source of the material, the unbelievable consistency of the results makes me think we have a slam-dunk signal for organics on Mars", Eigenbrode said. And now they've added a catalogue of organic molecules to that list. What the authors have found is a systematic variation in methane concentration with season, with the highest concentrations occurring at the Gale Crater towards the end of the northern summer. On Earth, such carbon-rich compounds are one of life's cornerstones.
Scientists realized that they had to take a step back and try a more cautious, methodical approach. I'll tell you what comes from Mars: Hell. So like the organic molecules, it's not an unambiguous biosignature.
"The question of whether life might have originated or existed on Mars is a lot more opportune now that we know that organic molecules were present on its surface at the time", wrote Utrecht University astrobiologist Inge Loes ten Kate of the Netherlands.