There may be some useful changes coming to NASA:
JPL has butted heads with the office over the next big mission, the Mars 2020 rover, which will gather rock samples for later retrieval to Earth. JPL is interesting in having the rover target areas with subsurface brines, an activity that would not be allowed with its planned level of cleanliness. Moreover, the planetary protection office has not yet agreed on the efficacy of the techniques JPL will use to sterilize the tubes in which the rover will cache rock cores. If the issues aren’t resolved, Rummel says, the rover could be headed for a bureaucratic “train wreck”.
The office, which has always been limited by a small budget and staff, continues to gauge a spacecraft’s “bioburden” based on a classic measure—the number of cultivable microbial spores it carries. “Some of the numbers we’ve been operating on date back decades, and it’d be great to revisit them,” says Sarah Johnson, a planetary scientist at Georgetown University in Washington, D.C. She thinks the office should take advantage of two innovations: chemicals that can separate DNA from dead and living cells, and genomic sequencers that can classify the living ones by type. Scientists could then, for example, assess their individual likelihoods of surviving on Mars.
As a member of the Curiosity team, Johnson would like to see a change in policy that would allow the rover to sidle up to the wet streaks to give them a close look, even if the drill itself—currently on the fritz since December 2016—could not be used. In their op-ed, Fairén and his colleagues go further, saying NASA should slightly lower its sterilization standards so that robots as clean as Curiosity could explore special regions. Fairén says there is growing evidence that the harsh environment on the martian surface—a combination of frigid temperatures, caustic chemicals and deadly cosmic radiation—would kill Earth’s microbes quickly, especially in the limited numbers that ride along with robots. Even if some survive, he adds, future missions could distinguish between earthly and martian microbes by sequencing their genomes.
As the article notes, it’s inevitable that humans are going to go there. If they want to look for non-terrestrial life, they need to start doing it now.