Chasing Martians – the Contamination team of PolAres

A presumably impossible job? “Maybe not”, says Ulrich Luger, a biologist working in the contamination team of PolAres at the University of Innsbruck.

Imagine this: An astronaut sampling martian soil is picking up an interesting specimen, brings it back to the lab, puts it into the DNA sequencer and *bing* after two hours, the machine blinks and gives an answer to one of the most profound questions of humanity – whether life is uniquely found on Earth or if it might be prevalent in the universe. The crewman checks the machine and finds out that the DNA sequence he found was almost human, aehmm... well... precisely human to be exact. Does that mean that there is proof for human-like extraterrestrial life? No – you’ve just busted a 100 Billion Euro space mission by spoiling the pristinity of the very sample you’ve analysed. That’s bad press and probably the biggest embarrassment in your career.

“In order to prevent this, our team –comprised of Birgit Sattler, Vanessa Fillafer, Gernot Groemer and myself- is working on techniques to trace contamination”, Ulrich Luger summarizes. Contamination works both ways: On the one hand we do not want to see alien organisms to enter the Earths’ biosphere (which is rather unlikely, but still possible in principle) after the return of a crewed Mars vessel. On the other hand, which is more probable, we risk the accidental insertion of terrestrial bioload into the Martian environment and therefore might mistake it for traces of indigenous life.

Vanessa Fillafer, a student of physics at the University of Innsbruck -together with Gernot Groemer- is working on a realistic soil surrogate based upon JSC1a-Mars soil simulant mixed with fluorescent microspherules. “Instead of using real microbes –which would be difficult to trace and hard to handle in a non-sterile field setting- we choose these microscopic particles as replacement for real biological substrata,” Vanessa outlines the strategy, “As we will have a precise understanding of the contamination behaviour of the microspherules, they will be used as tracers during all Mars analogue field activities. This is our method of quantitatively studying the amount of forward and backward contamination for a wide range of applications, including planetary surface activities like drilling, etc... , but also sample procurement in general.”

So do the team members believe in extinct or extant life on the Red Planet? “We just don’t know, but the truth is out there”, smiles Vanessa.