Despite the best efforts of NASA, it's impossible to put craft into space that are entirely clean. Now, a study shows that Curiosity was sent up to Mars with 377 strains of microbes aboard — and up to 11 per cent may have made it to the surface of the red planet.
Swabs taken prior to launch show that a surprising 377 types of microbe withstood the specialised spacecraft cleaning methods used by NASA ahead of launch, reports Nature. In the lab, scientists from the University of Idaho in Moscow have since exposed all 377 to the extreme conditions that Curiosity underwent during its trip to Mars, including desiccation, UV exposure, cold and pH extremes.
All told, 11 per cent of the 377 microbial strains survived more than one of those conditions, which means it's likely that some will have found their way to the planet. Not, perhaps, the kind of life that NASA really wants to send to Mars. The results were presented yesterday at the annual meeting of the American Society for Microbiology.
Indeed, the news may reinforce previous reports which suggested that Curiosity project developers didn't follow NASA's planetary protection protocols closely enough. That may or may not be problem: some argue that we're being overprotective of Mars, while others correctly point out that we're working with a limited number of data points. Or, err, none, if you want to be all technical about it.
Regardless, the new data should at least help scientists evaluate their clearing procedures in the future. That could be crucial for future missions to Mars that are planned to bring samples back to Earth for analysis — because otherwise we might merely identify microbes that we sent to the planet in the first place. [Nature]