Mars Mystery: What HAS Curiosity Discovered?

Mission scientists hint at a "historic" discovery by the Mars Science Laboratory -- but no details will be announced until further tests are carried out.

Science isn't something that just happens overnight. It takes many measurements, oodles of analysis, re-testing and re-analysis before any groundbreaking announcement can be made.

So, on the surface of Mars, inside Gale Crater on a plain called Aeolis Palus, our tenacious six-wheeled Mars Science Laboratory (MSL) is doing cutting-edge laboratory work on an alien world and mission scientists are itching to announce a "historic" discovery.

"This data is gonna be one for the history books. It's looking really good," John Grotzinger, lead scientist of the MSL mission, said in an interview with NPR.

But what is he referring to and why all the secrecy?

For the past few weeks, rover Curiosity has been busily scooping dirt from a sandy ridge in a geologically interesting location called "Rocknest." Using a little scooper attached to its instrument-laden robotic arm, Curiosity has been carefully digging, shaking and dumping the fine soil grains into its Sample Analysis at Mars (SAM) and Chemistry and Mineralogy (CheMin) instruments.

Recently, NASA announced some results from SAM after analyzing samples of Mars air. Interestingly, clues as to Martian atmospheric history were uncovered. Also, mission scientists announced an apparent dearth of methane in the air - a result that undoubtedly frustrated many hoping for the detection of the gas that may, ultimately, reveal the presence of sub-surface microbial life.

It appears that SAM has made yet another profound discovery... but mission scientists are keeping quiet for the time being.

One of the prime mission objectives is for Curiosity is to understand the past and current habitability for life on the Red Planet. Curiosity can not directly detect the presence of Mars life, but it has been kitted-out with miniature laboratories capable of not only establishing what materials soil samples contain, but also whether the Mars soil contains carbon-laden organic molecules.

Should Curiosity detect these organics, the mission will have confirmed the presence of the building blocks of life on the surface of Mars. This does not, however, infer the genesis of life on Mars, it just means that some of the ingredients are there.

According to this NPR article, Grotzinger refers to the SAM data as being the source of the excitement. Indeed, one of the instrument's objectives is to address "carbon chemistry through a search for organic compounds, the chemical state of light elements other than carbon, and isotopic tracers of planetary change," according to the JPL mission site.

Might these data indicate the detection of organic chemistry? This would certainly be "historic" news. Also, this would back up the Viking landers' likely discovery of organics in the 1970s - a result that could only be confirmed after Mars lander Phoenix made the groundbreaking 2008 discovery that the Martian surface is laced with perchorates.

Although the focus appears to be on organics, this is pure speculation for now. Science isn't about announcing the first result, no matter how profound, historic or earth-shattering it appears to be. As an example, the initial SAM results for Martian air analysis hinted at the presence of methane, only for that result to be proven false during follow-up tests - air from Earth (which does contain methane) was trapped in the instrument and needed to be flushed out before pure Mars air could be properly analyzed.

NASA JPL mission scientists have, again, rightly decided that nothing needs to be announced until further work is done - even though they've communicated their excitement for a big discovery. They are, after all, human.

So now we wait...

The view from Curiosity after re-commencing its drive on sol 102 of the mission after camping out at Rocknest.