As a follow-up to the previous article regarding the new “one for the history books” discovery made by the Curiosity rover, it is now being reported in the last couple days, by Space.com and Wired, among others, that the results will be announced during the upcoming American Geophysical Union (AGU) meeting in San Francisco, which runs from December 3-7.
What exactly the discovery is still isn’t known, but most knowledable space experts are saying it likely has to do with organic (carbon-based) molecules, since it is the Sample Analysis at Mars (SAM) instruments involved, which are designed to look for organics in the soil among other things.
The question of whether Mars has any organics on its surface has been a hotly debated one ever since the Viking landers landed in the 1970s. At the time, the life-detection experiments (for microbes) seemed to give positive results, but then other experiments failed to find any organics in the soil. You can’t have life without organics, since that is what living things are made of. It was presumed that some mystery oxidant in the soil was destroying any organic molecules that might be there, and might mean life was impossible as well.
Since then, however, findings from other subsequent missions have provided more clues. The Phoenix lander found that the soil contained large amounts of perchlorates, which can easily destroy organic compounds when heated, and that is just what the Viking tests did as part of their experiments. Perchlorates also wouldn’t necessary be lethal to life, so it left the door open to the possibility that the Viking life-detection results may have been accurate after all, while also explaining the lack of the organics themselves.
There should be at least traces of organics on Mars’ surface, since meteorites contain them as well, and they come down to the Martian surface quite often, just as on Earth, etc. More likely even, organics could be found just under the surface, protected from the harsh ultraviolet radiation from the Sun.
They can either form on their own without biology or they can be the result or remnants of living things. Finding organics that originated on Mars itself, especially more complex ones, would be more interesting than those that simply fell from space. Can Curiosity tell the difference?
Curiosity isn’t a life-detection mission the way that Viking was, but it can analyze any organics found and provide clues as to their origin, using SAM. Two good videos to check out are this short interview with John Grotzinger, the mission’s principal investigator and another interview with Daniel Glavin, part of the team which developed SAM. Curiosity can look at the isoptopic ratios of the organic molecules and also possibly identify biosignatures should any exist.
You can also listen to Grotzinger’s original comments here, which started this whole internet wave of speculation to begin with.
In the meantime, we will just have to wait to hear what the Curiosity team has to say. While it probably won’t be about finding life itself, as many have been hoping, it should still be very interesting and may even shed some more light on that age-old mystery.
This article was first published on Examiner.com.