Possible Contamination, Bacteria hitched a ride to Mars Options

[mike]

Indeed. It seems to me it's impossible for us not to transport some living material to Mars, the Moon, and whereever else. If it weren't for the human organism being somehow superior to other competing organisms here on Earth, we wouldn't be here sending things into space in the first place. And if some bug from Mars or the Moon or whereever else takes us out, so be it.

[tedstryk]

Indeed.  It seems to me it's impossible for us not to transport some living material to Mars, the Moon, and whereever else.  If it weren't for the human organism being somehow superior to other competing organisms here on Earth, we wouldn't be here sending things into space in the first place.  And if some bug from Mars or the Moon or whereever else takes us out, so be it. 

I agree in the case of Mars. But in the case of the moon, so much material has probably gone back and forth due to impact ejecta and such in relatively short time scales compared to the trip to Mars that I really don't think that we need to be too elaborate with sterilization. At an rate, there is little possibility, even if it can survive in a dormant state, of earth-life taking on the moon. And now, post-Apollo, if the moon can be contaminated, it already is. In fact, the moon might be an interesting proving ground to test bacteria's survival in space, by revisiting the Apollo areas with sterilized rovers and looking for life!.

[Sdetton]

Forgive me if this sounds simple minded, but what is so terrible about bacterial or viral particle contamination on Mars? I never understood how life could be considered as "pollution" on a (as far as we know) lifeless world such as Mars. Isn't one of our main goals to seed and spread life throughout the solar system? As one member mentioned, if we are ever to colonize or terraform any other planet or satellite, then we will obviously introduce other forms of life such as simple microorganisms, certain plants (for food), and possibly insects.

Of course there might be a few negative aspects from this contamination (possible new pathogens, hindrance to our search for native life, etc), but in my view the benefits far outweigh the downsides.

[djellison]

"(as far as we know) lifeless world such as Mars."

Thats the point - we dont know that it's lifeless and indeed there's plenty of evidence that it may indeed have life now, or have had it in the past.

If it does have life - life totally different and unique to ours - contamination with life from our OWN planet may kill it off

And that would be a crime beyond all description imho

Doug

[DEChengst]

The simple act of observing something changes it, to a greater or lesser degree.  That's an immutable fact of the Universe (and is inherent in the very fabric of a quantum Universe).

Heisenberg is speeding down the highway at 150 mph. A cop pulls him over and asks "Do you know how fast you were going ?" "I have no idea", Heisenberg replied, "but I knew exactly where I was"

[Bill Harris]

I'm thinking more in terms of paleo-life signs than of recent life. One possible way to find ancient Martian life would be to look for organic markers and DNA fragments and it would be a shame to not be able to determine if a DNA fragment is ours or theirs. It would not be good to obfuscate signs of Martian life while searching for it. It may be a moot point, but better to err on the side of caution.

--Bill

[Sdetton]

"(as far as we know) lifeless world such as Mars."

Thats the point - we dont know that it's lifeless and indeed there's plenty of evidence that it may indeed have life now, or have had it in the past.

If it does have life - life totally different and unique to ours - contamination with life from our OWN planet may kill it off

And that would be a crime beyond all description imho

Doug

That's assuming that earth life will be so prolific as to spread all over the planet. This is quite unlikely even for thousands of years after contamination has occured. If they even survive, the microorganisms would take very long to adapt and spread from one nutrient rich niche to another. And of course theres fact that contamination already occured naturally as stated in the thread by others, which makes the sterilization attempts superfluous (in my opinion at least).

[mike]

"(as far as we know) lifeless world such as Mars."

Thats the point - we dont know that it's lifeless and indeed there's plenty of evidence that it may indeed have life now, or have had it in the past.

If it does have life - life totally different and unique to ours - contamination with life from our OWN planet may kill it off

And that would be a crime beyond all description imho

Doug

The thing is that as humans we have had to eradicate various other competing species in order to advance far enough to go into space in the first place. I agree that we should not actively seek to destroy whatever other living things exist in the universe, but surely some extinctions are inevitable. Should we just orbit Mars and never actually land lest we destroy something or other? What if something falls off an orbiter and contaminates Mars? Perhaps we should sterilize the Earth altogether, in case a meteor strike knocks off some life and lands it on Mars?

And suppose our probes are entirely sterile - what about the rocks we're damaging and dunes we're flattening? What about the dead orbiters littering the space around Mars and, eventually, Mars itself?

At some point it's absurd, and personally I can live with a few puny organisms accidentally destroyed if it means learning new things and gaining access to useful minerals/artifacts/whatever. If I were worried about killing anything, I'd never take a shower, I'd never cook my food, I wouldn't kill fruit flies, etc. etc. etc.

[djellison]

You have to admit - damaging a species native to another planet is a little different to accidentally standing on a woodlouse

To quote the Medicine Man we're currently taking 'all precautions' - and it's wise to do so, if for no other reason than if/when we detect life on mars, no one can say "that's not life on mars, thats the life we took with us"

Doug

[Guest_Edward Schmitz_*]

It's probably been done by nature already - ejecta from impacts on earth making it to Mars is not out of the question

Doug

Yes, people always forget that this is happening all the time. When they consider a sample return mission, there is a bunch of hype about killing everyone with martian microbs. If that was going to happen, it probably already would have. The hand full of martian meteors that we have found are just the tip of the iceberg. The return trip is harder for rocks ejected from earth, but it has to be happening at a high enough rate to completely overwhelm anything that the rovers sent.

We need to do a best effort at cleaning and then forget about it.

[Guest_Edward Schmitz_*]

Forgive me if this sounds simple minded...

It does sound simple minded. The question is important. It bears directly on the reason that we are exploring Mars, in the first place. If we find life on mars in the next ten or twenty years and it looks very much like earth based life, we will not know if that was introduced by us or evolved independantly.

I still feel that we should move forward with a best effort, but that is not to say that the question is trivial.

ed

[Guest_Edward Schmitz_*]

That's assuming that earth life will be so prolific as to spread all over the planet. This is quite unlikely even for thousands of years after contamination has occured. If they even survive, the microorganisms would take very long to adapt and spread from one nutrient rich niche to another. And of course theres fact that contamination already occured naturally as stated in the thread by others, which makes the sterilization attempts superfluous (in my opinion at least).

Where are you getting these "facts"? "Thousands of years"? How do you know that sterilization is superfluous? Maybe the only earth microb that will survive on mars can't make the long journey on a rock, but the rovers are an exceptable transport.

ed

[tedstryk]

I think that the big reason that the contamination of Mars is a big deal is that it is possible that life evolved on its own there. Also, it might have naturally transmigrated via meteors and taken hold there. Unlikely, but possible. Contaminating it via spacecraft might lead to a situation in which we will never know if the life we are studing, should we find it, came from Earth via meteors, is indigenous to Mars, or was carried by our own missions. Thus, it is a big deal. This recent story however isn't. This did not come from the scientific community, but an author shamelessly trying to promote his book, and a hapless journalist who fell for it. Also, wouldn't it be tragic to find the remains of dead martian bacteria, and to discover that its end was brought about by agressive bacteria brought by us!

[dvandorn]

Well, yes -- introducing strains of bacteria that are more successful than native Martian bacteria, up until the point where you've learned as much as you can from the native stuff and preserved it in laboratories and protected zones, is not a good idea.

But consider -- it is really, really unlikely that present-day Martian bacteria live anywhere near the surface of mars. Especially not near enough to the surface for any of the chicken-scratchings our probes have made to get anywhere close to it.

It's been mentioned that the real threat would be for terrestrial organisms to find nutrient-rich environments (which, I will add, must be protected from the surface radiation environment) and overcome any native forms. And I ask, with all sincerity -- just where would one find a nutrient-rich and radation-protected environment near enough the surface of Mars to allow terrestrial bacteria to move from a landed probe into them? And remember, the radiation environment at the surface is a pretty good sterilizer -- any transport mechanism you postulate would have to figure out how to get terrestrial organisms to the protected environments quickly, before the radiation environment destroyed them.

I would be fascinated to hear about any theories of such a transport mechanism that don't depend, at some point or another, on the infamous "and then a miracle occurs" step in the process...

-the other Doug

[djellison]

it is really, really unlikely...

But not impossible

Doug