After four years of studiosly ignoring what might be the most interesting destinations on its path due to concerns over planetary protection, NASA is consideing letting its Curisoity Rover operating in Mars’ Gale Crater, have a bit more leash.
“Pending approval of a mission extension, NASA’s Curiosity Mars rover will continue to climb to progressively higher and younger strata on Mount Sharp, investigating how long the ancient, water-rich environments found so far persisted as Mars dried out. Reaching those destinations would bring the rover closer to locations where dark streaks are present on some slopes. On the way, the route would allow the one-ton rover to capture images of the potential water sites from miles away and see if any are the seasonally changing type.
The features of interest have been observed by NASA’s High-Resolution Imaging Science Experiment (HiRISE) camera on the Mars Reconnaissance Orbiter (MRO). They appear as dark lines that appear to ebb and flow over time. Planetary scientists think these gullies or recurring slope lineae (RSLs) may appear seasonally as a form of briny water at or near the surface of the Red Planet under warmer conditions.
There are two RSL candidates that may be within Curiosity’s reach, on the side of the 3.1 mile (5 kilometer) Mount Sharp. The rover’s Remote Micro-Imager (part of ChemCam) would be the main instrument for imaging the possible sites. The goal would be to study the regions over time to see if there are any changes and to rule out other causes for the changes, such as dry avalanches.
How close could the rover safely get to an RSL? “That’s exactly the question that needs to be addressed early in the process,” said Catharine Conley, NASA’s planetary protection officer. “Kilometers away—it’s unlikely that it would be an issue. In terms of coming much closer, we need to understand well in advance the potential for Earth organisms to come off the rover, and that will tell us how far away the rover should stay.”
Conley notes that while the Martian environment is considered harsh for many organisms, that’s not necessarily the case for all of them—particularly microbes that might be hiding within the nooks and crannies of a robotic explorer.
The darkish streaks are considered “special regions” on Mars, where extra precautions must be taken to prevent contamination because of the suspected presence of liquid water, considered a prerequisite for life.”
The potential change in approach, although still hyper-cautious, as the story excerpt demonstrates, is no doubt due to a number of factors, but among them may be a recognition of the rapidly shrinking time-frame for studying Mars in its “pristine” state.
Whether some elements may like it or not, the Red Planet will soon be seeing an increase in robotic visitors from its nearest neighbor. And not far behind, possibly in as few as 10 years, and likely not more than 20, will be humans, arriving in what the Planetary Society calls our “filthy, meat-bag bodies.”
The reasons for avoiding unintentional contamination of areas which could possibly host microbial organisms are sound, beginning with the fact that it could lead to false positives in the search for Martian life. On the other hand, they could prove to be self-defeating as well. In order to “follow the water” which has been NASA’s mantra in the ongoing robotic Mars campaign, it is eventually necessary to actually go where it is wet.
And in this case, eventually isn’t as long as it used to be.