Could it be worthwhile to bring a small and simple greenhouse with biofilms along with one of the next missions to Mars?

Planetary protection rules could be a reason not to bring biofilms to Mars, but because several landers and satellites that crashed or landed on Mars were probably not sterilized these rules were broken already many times.

Nostoc Commune is a species of cyanobacteria that develop a biofilm that serves as a protection against harsh conditions.
They use the energy of light to synthesize organic compounds from CO$$_2$$ and produce O$$_2$$ this way.

Photo taken by YAMAMAYA

Because of this biofilm Nostoc Commune bacteria can survive high levels of UV radiation, are resistant to heat and repeated patterns of freezing and thawing and can survive long periods without water.

So why not place these bacteria with their biofilm in a simple plastic cover on a clay-rich, lowland region near the equator so that they are only protected against the dusty winds ?

With a camera to take only one image a day it would be very interesting to see if they can survive the harsh conditions on this planet.

• The only bit of this which is not doable now on Earth is replicating the exact chemnistry of the Martian soils, and the reduced gravity, which seems unlikely to be much of a factor for something this small. Current rovers will give us a lot of information about the soils, and in a few more years, probably return samples, which can be analyzed on Earth to give complete information. Then we can replicate the conditions and do this experiment on Earth. – Steve Linton Dec 17 '18 at 12:11
• I think this question is really unclear. While you're asking "why not?", scientists would rather ask "why should we?" and "what would we learn from it?", and the answers to the latter two questions would exclude placing any biofilms on Mars. I'm not sure what your question is aiming at exactly, but if you want to terraform mars, then that's not where we're heading at the moment. – AtmosphericPrisonEscape Dec 17 '18 at 15:32
• @AtmosphericPrisonEscape Like the investigations of Curiosity are very interesting for geologists, placing biofilms could be very interesting for biologists and especially astrobiologists. It would also be a milestone for life in general and thus an advertising event to the public. – Conelisinspace Dec 17 '18 at 15:47
• So is your actual question then "What could we learn from placing a biofilm on Mars, that we couldn't learn from placing it on a terrestrial Mars-analogue?" – AtmosphericPrisonEscape Dec 17 '18 at 15:50
• Think about planetary formation, planetary as well as atmospheric evolution, and maybe even the origin of life on Earth. If you erase the surface signature of those histories, then we would loose a major comparison point of Earth with a similar planet that stopped being geologically active very early on. – AtmosphericPrisonEscape Dec 17 '18 at 20:03