> Contamination risk is a real showstopper for Mars, one of those problems that gets worse the more carefully you look at it.
Not just Mars but anywhere humans choose to go to. Since
a) discovery of extremophiles;
b) humans themselves are a living (and flourishing) bioweapon (from an extraterristrial world's perspective)
– we have to accept a simple fact that full decontamination or sanitation is not possible, at least not at the current level of the technological progress of our civilisation.
There will be microorganisms that will survive UV, α-, β-, γ- and X-rays albeit in reduced numbers. A single toilet flush in certain cirumstances can be a biological catastrophe even here on Earth today, and a single bowel movement might yield a unmitigated disaster in extraterrestrial worlds that could wipe alien biomes or civilisations out. And select extremophiles will absolutely take advantage of a new environment, adapt and evolve. What the extremophiles will evolve into and that might entail for an extreterrial world as well as ramifications for humans are the biggest unknowns.
Then, at the extreme end we have prions here on Earth that we do not understand, can't neutralise, can't decontaminate prion infected surfaces and tools, and – more generally – can't contain the prions in any way other than hurling them into a nearby star (not practically possible today). What the prions will be able to do in a unknown environment is a very uneasy thought at the very least.
So the actual question is: what is the solution? Should we stop the space exploration out of fears of infecting other worlds with terrestrial microbiomes, sit around and do nothing? We won't even be able to visit asteroids in our own solar system if we do not find a way to allay our own fears.
Or, should we keep the humans on Earth, send out robotic missions instead and deprive the humans of fun of exploring new worlds and satisfying our own curiosity? We are curious creatures.
I don't understand why that is a concern. Whether some microorganisms live or die because of us ultimately is of no importance. What we should concern ourselves however, is any risks posed by them to us.
Not just Mars but anywhere humans choose to go to. Since
a) discovery of extremophiles; b) humans themselves are a living (and flourishing) bioweapon (from an extraterristrial world's perspective)
– we have to accept a simple fact that full decontamination or sanitation is not possible, at least not at the current level of the technological progress of our civilisation.
There will be microorganisms that will survive UV, α-, β-, γ- and X-rays albeit in reduced numbers. A single toilet flush in certain cirumstances can be a biological catastrophe even here on Earth today, and a single bowel movement might yield a unmitigated disaster in extraterrestrial worlds that could wipe alien biomes or civilisations out. And select extremophiles will absolutely take advantage of a new environment, adapt and evolve. What the extremophiles will evolve into and that might entail for an extreterrial world as well as ramifications for humans are the biggest unknowns.
Then, at the extreme end we have prions here on Earth that we do not understand, can't neutralise, can't decontaminate prion infected surfaces and tools, and – more generally – can't contain the prions in any way other than hurling them into a nearby star (not practically possible today). What the prions will be able to do in a unknown environment is a very uneasy thought at the very least.
So the actual question is: what is the solution? Should we stop the space exploration out of fears of infecting other worlds with terrestrial microbiomes, sit around and do nothing? We won't even be able to visit asteroids in our own solar system if we do not find a way to allay our own fears.
Or, should we keep the humans on Earth, send out robotic missions instead and deprive the humans of fun of exploring new worlds and satisfying our own curiosity? We are curious creatures.
We need a solution.