Curiosity Rover May Have Brought Dozens of Microbes To Mars

bmahersciwriter (2955569) writes "Despite rigorous pre-flight cleaning, swabbing of the Curiosity Rover just prior to liftoff revealed some 377 strains of bacteria. 'In the lab, scientists exposed the microbes to desiccation, UV exposure, cold and pH extremes. Nearly 11% of the 377 strains survived more than one of these severe conditions. Thirty-one per cent of the resistant bacteria did not form tough, protective spore coats; the researchers suspect that they used other biochemical means of protection, such as metabolic changes.' While the risk of contaminating the red planet are unknown, knowing the types of strains that may have survived pre-flight cleaning may help rule out biological 'discoveries' if and when NASA carries out its plans to return a soil sample from Mars."

Re:What goes around comes around

[Zocalo]

Not just that, but by ignoring any bacteria that might have survived the trip from Earth to Mars aboard Curiosity (and presumably earlier probes all the way back to Viking) they could potentially be ruling out other strains of the same bacteria that may have made the trip by means such as impact ejecta. They are demonstrably up to the task in the lab, so potentially this could eliminate some of the most likely candidates for successful pan-spermia. If Mars is teaming with bacteria strain "foo" as a result of an earlier impact event, and "foo" just happens to have been detected on a Curiousity swab I hope there is also some plan to determine how likely it was that Curiousity was indeed responsible.

Policy for Planetary Protection

[Strider-]

JPL actually has a highly detailed document on "Policy for Planetary Protection" that details the standards to which a probe must be sanitized to before being sent on its mission. The level of cleanliness depends on the intended mission and target; orbiters have a lesser standard than landers, for example. The policy also takes into account different parts of the spacecraft; the inside of the box containing the CPU and so forth isn't cleaned to as high of a standard as the wheels, experiments and so forth that are directly exposed to the environment. In the case of the Galileo probe, it was deliberately crashed into Jupiter at the end of mission in order to ensure it would never impact Europa, as it had not been cleaned to that high of a standard. Cassini will face a parallel fate, of crashing into Saturn to prevent a collision with Enceladus and/or Titan.

The key part here is that when you are looking for life (or might be looking for life in the near future) you don't want to discover that the life is found is something that you brought from earth yourself, or was brought by another space probe.

Re:Achievement

[Strider-]

First properly documented interplanetary flight sent by us, with biological specimens on board ! Pity we didnt measure the effect of zero-g or deep space radiation on these.

It's actually assumed that every probe that is sent will have some form of bacteria and so forth on it; life is just so pervasive on this planet that it's impossible to perfectly sterilize everything. Instead, the goal is to strongly sterilize what's critical and exposed to the environment, and reduce the probability of accidental contamination to an acceptable level (currently defined to be in the neighbourhood of 1 in 10,000 chance).

Re:Experiment proposal

[Captain Hook]

???

Because it has a lot of implications about how life gets started on a planet which is an important line of investigation for science, isn't that obvious?

Re:Policy for Planetary Protection

[Anonymous Coward]

Here is a link to a newspaper with images of ISRO (Indian Space Research Organization) clean room where the Mars orbiter was assembled. Compared to NASA's cleanroom, this may not be very clean. They might bake out the satellite, but life is tough.

http://www.thehindu.com/sci-tech/science/indias-october-28-mars-mission-on-schedule-isro/article5204371.ece

http://www.nasa.gov/centers/jpl/news/msl20100916.html