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Canis Lupus
2010-Apr-10, 08:07 AM
Despite some optimistic views about other forms of life being out there, as yet there are no signs, just statistical speculations. I'm agnostic about the possibility, but live in hope. In the meantime, some thought about doing one of the things Man has been quite good at here on earth, but taken to a celestial level, wouldn't hurt - a form of space farming.

If I was given the task of finding life elsewhere other than Earth, I would cheat. Gather together extremophiles, plant them on moons and planets as best as possible to give them a head start, then let them adapt to the environment if they can; and, if they can, hope they adapt the environment they are in to evolve more complex forms of life, like life has here on earth.

The more places it is done, the higher the likelihood it would succeed. It has already been shown that microbes introduced to the moon by the Apollo missions were able to survive in a doormat state for several years. What would have happened if they were allowed to stay there undisturbed instead of bringing them back to earth is unknown, of course, but having seen how it could work through an accident, the occurrence does provide some inspiration or model for the possible seeding of life on other planets and moons on a very basic level, which involves minimal expense compared to the idea of colonisation by man.

It's a long long long term venture, but if it is Life which counts, does it matter that it is our form of life that goes out there, especially if there are more adaptable and resilient forms which could be given the task? We could be planting the seeds for a long term expansion of life throughout the universe although we may never be around to see its fruits.

We have gained hope from the discovery of extremophiles here on earth that life may exist even in quite different environments to Earth's. I can't see the problem in pushing that idea one step further to take active steps to make it happen rather than just hoping it has already. The biggest obstacle to life may be its first formation. After that occurs, evolution may quickly take over and it has a proven record of achieving the most remarkable changes both to life and its environment on a grand scale.

I doubt whether I am the first person to have this idea. My apologies if it has been discussed elsewhere or touched upon.

ravens_cry
2010-Apr-10, 09:20 AM
Seeding life elsewhere may, or may not, be a good idea. But I think we should try to make sure there's no life there to begin with before we start planting kudzu. The discovery of extraterrestrial life would be so significant that destroying it in our attempt to extend our biosphere would be a terrible crime, in my opinion.

Canis Lupus
2010-Apr-10, 12:26 PM
Seeding life elsewhere may, or may not, be a good idea. But I think we should try to make sure there's no life there to begin with before we start planting kudzu. The discovery of extraterrestrial life would be so significant that destroying it in our attempt to extend our biosphere would be a terrible crime, in my opinion.

That type of thinking leads to unduly negative consequences. You might as well say goodbye forever to the idea of life expanding beyond this planet, including manned expeditions. Mankind is probably never going to be able to "make sure" there is no life anywhere to begin with somewhere unless it goes there to do extensive exploration and research, and in the process providing prohibitively expensive barriers. But even if it was to do so, it would run into the problem you raise and imagine is important because of the risk of contamination. It's self-defeating.

Yes, make some exploration for signs of life, but don't hold your breath on a billion to one chance.

We really don't need the Greenpeace movement in space. It causes enough problems here on earth without the mentality going spaceward.

We may have already done this inadvertently to Titan, Mars, Venus and Jupiter. We certainly did it with our own moon by accident and organisms still managed to survive. How much more successful could it be if we put a bit of will and thought into it?

IsaacKuo
2010-Apr-10, 02:11 PM
You might as well say goodbye forever to the idea of life expanding beyond this planet, including manned expeditions.
You're assuming that we need to exploit the resources of potentially inhabited planetary bodies in order to expand beyond this planet. That's not true. We can (and IMHO should) expand beyond our planet using space colonies. Those colonies would best be built and supplied using resources from small bodies--especially comets and other icy bodies which are rich in CHON volatiles. These bodies are very likely completely devoid of life...spending billions of years frozen solid at 3 degrees kelvin with practically no power input would plausibly guarantee it.

centsworth_II
2010-Apr-10, 05:42 PM
...If I was given the task of finding life elsewhere other than Earth, I would cheat.... This ignores the most important reason for finding ET life in the solar system. That is to study it and compare it to Earth life so that we better understand Earth life and life in general. Contaminating the prospective study samples would be disastrous.

eburacum45
2010-Apr-10, 07:37 PM
If I was given the task of finding life elsewhere other than Earth, I would cheat. Gather together extremophiles, plant them on moons and planets as best as possible to give them a head start, then let them adapt to the environment if they can; and, if they can, hope they adapt the environment they are in to evolve more complex forms of life, like life has here on earth. Note that extremophiles are specialists, adapted to particular environments on Earth which are not really anything like the environments encountered on other planets. In all probability a strategy of using unmodified Earth organisms will fail.

That is not really a great problem; given a couple of hundred years of developments in genetic engineering I am pretty sure humanity will be able to create its own extremophiles, tailor-made to adapt to extraterrestrial environments. The pace of development in space exploration is slow, especially right now; it will probably be at least a couple of hundred years before humanity is ready to start colonising other worlds.

. It has already been shown that microbes introduced to the moon by the Apollo missions were able to survive in a doormat state for several years. That's not absolutely proven, actually. See this page for discussion of this event.
http://en.wikipedia.org/wiki/Reports_of_Streptococcus_mitis_on_the_moon

clint
2010-Apr-10, 10:44 PM
You might as well say goodbye forever to the idea of life expanding beyond this planet, including manned expeditions...

Let me try and understand your point:
so deciding not to deliberately bombard alien worlds with earthly extremophiles necessarily means saying goodbye to manned exploration? Huh...


We may have already done this inadvertently to Titan, Mars, Venus and Jupiter. We certainly did it with our own moon by accident and organisms still managed to survive. How much more successful could it be if we put a bit of will and thought into it?

Maybe it's only me, but I do see some slight conceptual difference between accidentally exporting the odd handful of microbes on a space probe and embarking on a full-scale extremophile colonization project.

J Riff
2010-Apr-10, 11:40 PM
Can't see much point in extending our bacteria into the solar system... it would take aeons to evolve into anything... and we could have a full colony in space or on said planet by then, with all our advanced life-forms, AND not disturb the native ecology.

marsbug
2010-Apr-10, 11:46 PM
Certainly we want to preserve possible past and present habitats for alien life, until they have been thouroghly investigated. However the idea of seeding an extraterrestrial environment which is known to be lifeless with earth life is enticing.

There must also be sensible limits to how hard we look before we declare a body sterile. We should not insist that every square meter of mars (for example) be analysed to a depth of kilometers before we admit there is nothing there.

There are many bodies which we can already say with a high degree of confidence are lifeless. Many of these are water ice and organic material rich. Studying these objects for their own sake is a worthy endevour. We can also learn much about life from chemical systems which may have progressed partway towards life under the influence of natural heat sources whch vanished long ago, and water ice and organic rich bodies are ideal spots to do such studies.

However there will come a point when we can say we have learned all we realistically can from such places.

At that point warming(or moistening or otherwise providing whatever essential elements of habitability are absent) a small spot of such a world, and seeding with earth life becomes hard to object to, and would provide a chance to see how earth life can adapt to a variety of alien environments. I'm not saying we should start tomorrow, but we shouldn't dismiss the idea forever either.

A well explored icy main belt asteroid would be a good place to start.

Canis Lupus
2010-Apr-11, 02:56 AM
Let me try and understand your point: so deciding not to deliberately bombard alien worlds with earthly extremophiles necessarily means saying goodbye to manned exploration? Huh...

I don't think using emotive words like "bombard" helps. Does a farmer "bombard" his land with seeds? The logical extension of your idea would have meant no manned missions to the moon because of fear of contamination. Manned missions to Mars would be stalled almost indefinitely while we try to determine if there is any type of life there also, all while being handicapped by preventing ourselves on the ground examination, except with the sterilized probes, which could conceivably be carrying life despite the sterilization. It's not a "Huh", it's just your thinking taken to its logical end.


Maybe it's only me, but I do see some slight conceptual difference between accidentally exporting the odd handful of microbes on a space probe and embarking on a full-scale extremophile colonization project.

Yes, there is a conceptual difference, but that's the point, so I am failing to see yours. Keep in mind that the idea is not only a modification of the concept you have mentioned, but also the theory that life may have arrived here by much the same means, only naturally with an impact. Like the farmers who learned about seeding from nature, we would be doing much the same.


Can't see much point in extending our bacteria into the solar system... it would take aeons to evolve into anything... and we could have a full colony in space or on said planet by then, with all our advanced life-forms ...

Strictly speaking it has already evolved into something, and it may not take long to evolve into something else once there. It would, however, take a long time to evolve into anything resembling the more complex life forms on earth and to alter the environment like life here on earth. That doesn't mean we cannot monitor early progress and see immediate results. The mere fact of their immediate survival will be immensely rewarding in itself, and if later monitoring indicates some evolution or adaption taking place, then we can feel greater confidence the venture will be successful, although the its long term results may never be known to us.

If you think in terms of Man going out there, then this idea is not the one for you, but if you think in terms of life generally without prejudice to our particular species, and also with the idea that evolutionary forces will tend to produce more and more complex and intelligent forms, there exists the possibility of producing in the long term something akin to ourselves, but adapted perfectly to the new environment through its own unique evolution, like we have been on Earth.

Your model of exploration requires huge resources which there will never be a political will or justification for, as well as presenting incredible logistics and safety problems. The almost certain result of human colonisation attempting to live in a bubble in an alien environment is death and disaster.

Sorry, to seem like a pessimist on this point, but I see it rather as realism. To much can go wrong, and inevitably will go wrong. Grand ideas of colonies in space underestimate how well we are looked after or adapted to the environment we live in. "Nature's technology" is far more advance and subtle than Man's, capable of being self-sustaining and flexible. Ours is incredibly high maintenance n comparison, will come off the rails inevitably, and there will be no-one close at hand to help.


.... AND not disturb the native ecology.


What "native ecology" are you referring to? You are using a scientific term but with political environmental overtones, applying it to somewhere or something which at this point of time has no relevance. All science thus far points to no native ecology in the solar system apart from on Earth. All you can hang your hat on is a statistical hope.


Certainly we want to preserve possible past and present habitats for alien life, until they have been thouroghly investigated. However the idea of seeding an extraterrestrial environment which is known to be lifeless with earth life is enticing.

There must also be sensible limits to how hard we look before we declare a body sterile. We should not insist that every square meter of mars (for example) be analysed to a depth of kilometers before we admit there is nothing there.

There are many bodies which we can already say with a high degree of confidence are lifeless. Many of these are water ice and organic material rich. Studying these objects for their own sake is a worthy endevour. We can also learn much about life from chemical systems which may have progressed partway towards life under the influence of natural heat sources whch vanished long ago, and water ice and organic rich bodies are ideal spots to do such studies.

However there will come a point when we can say we have learned all we realistically can from such places.

At that point warming(or moistening or otherwise providing whatever essential elements of habitability are absent) a small spot of such a world, and seeding with earth life becomes hard to object to, and would provide a chance to see how earth life can adapt to a variety of alien environments. I'm not saying we should start tomorrow, but we shouldn't dismiss the idea forever either.

A well explored icy main belt asteroid would be a good place to start.

All very sensible, but one concern I have is deferral of the idea, or something similar, while awaiting all this research. The point you referring to as coming, may have already arrived. Even using the more moderate parameters for safeguards which you mention over the extreme space-greenies who have posted above, will involve considerable delay. A window of opportunity may exist, when this type of venture can happen. Lose it and it may not come again, or not for a very very very long time.

Despite modern views of history as ever onward and upward, study of history suggests that civilisations have their time spans. If you want me to extrapolate on this point, I will, but I am mindful of this not being a history forum. It should suffice to state, the Greeks and Romans who were pondering and examining the universe with mathematics and logic at one point of time, had a few hundred years later descended into a form of stupefying superstition.

Modern western technological societies are far from immune from this happening again. In fact, I think it is almost inevitable. We have the technology do this now within our solar system without the need to convince most of humanity to sacrifice huge resources, and in doing so extend their own earthly human suffering, possibly hastening the decline or durability of our civilisation.

Some people here seem not take into account the huge cost of space exploration, ignoring what is happening at the moment even, why the moon has not been visited for so long. Even further from their thinking is the possible social consequences of diverting these resources away from life on earth to sustaining ET Man. Members of this forum have a prejudice in favour of space exploration in one form or another. Your average Joe Blow and family are more occupied with paying the mortgage, putting food on the table and health issues, as well as other basics of life here on earth. They won't tolerate expensive manned spaced explorations without a compelling reason, which, short of the Earth facing imminent disaster, no-one will be able to provide them.

Keep it cheap and economical and there will be little threat from the wider population in support. Make it grandiose with visions of demanding and expensive space colonies and you will find politicians in power who oppose the vision shutting everything down to appease popular opposition. Impose it upon society, and what will be worse, are revolts and threats to the stability of society itself.

I agree the water worlds probably present the best possibility of the idea working, although a body like Titan appears to represent the closest thing there is a to a primitive earth. For Titan we can use life forms which are old, existed at a time when Earth's atmosphere resembled Titan's present one. On the water worlds we might be able to use more recently evolved organisms. In both cases, genetic engineering might be used prior to sending them, as mentioned by eburacum or at least some selective breeding to enhance their chances.

Important with this idea is some way of monitoring its early success. People will want to see some result even if it is the budget version of space colonisation. For this purpose, some accompanying satellite or on the ground sensor to detect the organisms on-going existence and progress would need to be added if possible.


That's not absolutely proven, actually. See this page for discussion of this event.
http://en.wikipedia.org/wiki/Reports_of_Streptococcus_mitis_on_the_moon

That's an interesting read. I didn't realise it was being disputed. It certainly provides grounds for an experiment. This could be done without sending anything to the moon - into space might be enough, or replicate something similar here on earth.

Bluevision
2010-Apr-11, 04:00 AM
Marsbug's post pretty much totally summed up my thoughts. You don't have to comb over every square meter of the planet/moon in question, just look in all the good hiding spots. If they're not there, do whatever you want. Seed it with extremophiles. I personally would advocate for fully terraforming it into as good an Earth as possible, but perhaps for bodies like Titan, some cool alien-esque biology would be cool (assuming that's even possible which I would doubt.)
The only thing I disagree is the end, that there will come a time that said life becomes useless and we could do whatever we want to it. That's where I have to bring morals into it and say we shouldn't annihilate an entire planetary biology or even do anything harmful to it just to make our own gains. Come on, the solar system alone is a giant place. If we have to give up one or even three bodies so we don't contaminate native life, that's hardly a major drawback.

Canis Lupus
2010-Apr-11, 04:32 AM
...
The only thing I disagree is the end, that there will come a time that said life becomes useless and we could do whatever we want to it. That's where I have to bring morals into it and say we shouldn't annihilate an entire planetary biology or even do anything harmful to it just to make our own gains. Come on, the solar system alone is a giant place. If we have to give up one or even three bodies so we don't contaminate native life, that's hardly a major drawback.

There is a possibility we won't be around to be doing what your morals have problems about once the ecology gets going, but assuming we are, isn't it like planting trees for harvest or breeding cattle for food? If we are the ones responsible for the ecology in the first place, I say it gives us a certain discretion, however, there is no need to see Man in opposition to the organisms or potentially evolving ecology. This concern seems to be an extension of the idea which underlies AGW theory (please forgive the mention) as MAN the pest, not part of nature. The life introduced will be part of our evolution, it represents part of us. We need not be its enemy, we are part of Nature also. The same considerations would apply elsewhere as here on earth, and those considerations lead to working in with an ecology, not annihilating it.

Bluevision
2010-Apr-11, 05:45 AM
Ah I see, he was talking about the life we created. I thought he was talking about life we found.

No, in the case that life just stagnates and we've tested the heck out of what's evolved, I don't think there's much of a moral side. It would just be bacteria after all. Perhaps not purposefully annihilate it, but don't be too worried about terraforming or paraterraforming a body like that.

clint
2010-Apr-11, 09:49 PM
I don't think using emotive words like "bombard" helps.Large-scale bio-seeding of a planet, as you propose, absolutely is equivalent to (biological) bombardment.


The logical extension of your idea would have meant no manned missions to the moon because of fear of contamination.On the contrary, my point was that exploration missions are in a completely different league than deliberate biological seeding missions (as you seem to propose).

It's like comparing a urine sample with an autopsy.
Why not wait with the autopsy until we are sure the patient is dead?
And why should that prevent us from analyzing its urine? Or even its blood and maybe some liver tissue?


Even using the more moderate parameters for safeguards which you mention over the extreme space-greenies who have posted above, will involve considerable delay.I think you misinterpret. This is not like preserving some rare bug on Earth. Detecting life beyond Earth, even primitive life, would be one of the most important scientific discoveries in the history of mankind. And we could learn a lot from studying it.

And, by the way, it would probably teach us much more about viable alien ecosystems than just shooting around earthly extremophiles ;o)

marsbug
2010-Apr-11, 10:35 PM
It need not be either/or. There are lots of almost-certainly-lifeless bodies with water ice and organics.

The moons poles for example! Edit: as has been pointed out earlier in the thread, a modest effort to seed a corner of a body known to be lifeless would attract much less opposition than grandiose mass 'extremophile lobbing' project. And creating a small amount of liquid water on an ice rich body, and seeding it, might well be a more achievable goal than putting a man on the moon! End Edit

Canis Lupus
2010-Apr-12, 08:17 AM
Large-scale bio-seeding of a planet, as you propose, absolutely is equivalent to (biological) bombardment.

Here we go again with the slanting of language, now its "large scale", another emotive use of language used to justify the previous one. It makes the idea seem something it's not. In terms of delivering parcels around the solar system, there is nothing large scale about it, not being much more than anything so far undertaken with probes and explorers. I am proposing microbes and a starter culture to give it a head start. It will be minuscule in size. It's monitoring may mean something larger but the actual delivery of the microbes is anything but "large scale". Even if a number were sprinkled about at different locations on the one body, describing it as anything large scale obscures the practicality of the idea - at least in its initial execution.


On the contrary, my point was that exploration missions are in a completely different league than deliberate biological seeding missions (as you seem to propose).

That depends on the context of the discussion. You wanted to "make sure". To that end, or at least comprising that end, the two ideas are potentially in the same league. Do I really need to spell out how exploration missions are already comprising your need to "make sure"?



I think you misinterpret. This is not like preserving some rare bug on Earth. Detecting life beyond Earth, even primitive life, would be one of the most important scientific discoveries in the history of mankind. And we could learn a lot from studying it.

Agreed, its implications are potentially enormous, but those implications themselves, provide a reason not to be too concerned about what you are saying. The implication of finding even one life-form outside of earth, implies a greater probability that the universe is sprinkled with life. This applies to several possible origins of the life form, whether it has a common origin with Earth's or it spontaneously was created on its own on the body independently of Earth. If you are looking to find that implication, why worry to much about a fractional possibility about one. There will be more out there. I agree that we should be looking for signs, but to go to the extent you seem to want to "make sure" appears extreme. For example, are you prepared presently to accept that our Moon and Mars are sterile bodies which this idea can be used on without the concern you are raising. If not, what must be done to satisfy you? You tell me, spell out the level of exploration which must be done for these two bodies before you are satisfied? Every scientific indication so far indicates they are life-less. Is this enough for you, what more do you want?


And, by the way, it would probably teach us much more about viable alien ecosystems than just shooting around earthly extremophiles ;o)

Sure it would, but you seem so sure that it will be found, that there is something there which we can learn this from, but there hasn't been a shred of evidence to support the idea of alien life, particularly in the solar system. All evidence points to the opposite. There is only theory, verging on wishful thinking, trying to overcome what the evidence is suggesting. Yet, you make statements which indicate incredible optimism. I share your hope we do find life, but hope should not get in the way of hard evidence pointing to different reality. In the meantime with this hope of yours you wish to suspend the very important idea of potentially spreading life.

We can passively hope for ET life or we can make it happen, at least in our neighbourhood.

Canis Lupus
2010-Apr-12, 12:42 PM
There is a term for this idea and like I thought it has been discussed a bit in one form or another, "Directed panspermia" - http://en.wikipedia.org/wiki/Panspermia

There is even a Panspermia Society: http://www.panspermia-society.com/



- The Interstellar Panspermia Society -

Dedicated to promote the future of life in space through directed panspermia. Payloads of selected microorganisms will start evolution in new solar systems. Panspermia missions can start in this century.

http://www.panspermia-society.com/


There is also a paper on it: Journal of the British Interplanetary Society 1997, 50, 93-102,
Michael N. Mautner,
Department of Chemistry, Virginia Commonwealth University, Richmond, VA, 23284
Department of Chemistry University of Canterbury, Christchurch 8001, New Zealand


Abstract

Microbial swarms aimed at star-forming regions of interstellar clouds can seed stellar associations of 10 - 100 young planetary systems. Swarms of millimeter size, milligram packets can be launched by 35 cm solar sails at 5E-4 c, to penetrate interstellar clouds. Selective capture in high-density planetary accretion zones of densities > 1E-17 kg m-3 is achieved by viscous drag. Strategies are evaluated to seed dense cloud cores, or individual protostellar condensations, accretion disks or young planets therein. Targeting the Ophiuchus cloud is described as a model system. The biological content, dispersed in 30 m m, 1E-10 kg capsules of 1E6 freeze-dried microorganisms each, may be captured by new planets or delivered to planets after incorporation first into carbonaceous asteroids and comets. These objects, as modelled by meteorite materials, contain biologically available organic and mineral nutrients that are shown to sustain microbial growth. The program may be driven by panbiotic ethics, predicated on:

1. The unique position of complex organic life amongst the structures of Nature;
2. Self-propagation as the basic propensity of the living pattern
3. the biophysical unity humans with of the organic, DNA/protein family of life; and
4. Consequently, the primary human purpose to safeguard and propagate our organic life-form.

This purpose may be best secured through a panbiotic program which may ultimately endow Life with universal consequence. Launched toward such purpose, panspermia missions with diverse microbial payloads will maximise the probability of survival and induce evolutionary pressures. In particular, eukaryotes and simple multicellular organisms can accelerate higher evolution. Statistical considerations based on the geometries and masses of star-forming regions suggest that the 1E24 kg carbon resources of one solar system, possibly ours, applied during its 5E9 yr lifespan, can seed all newly forming planetary systems in the galaxy.

http://www.panspermia-society.com/Panspermia_Technical.htm


I knew a good idea just can't be kept down, except first up, I would concentrate on our solar system, not other ones. The proposed idea by Mautner is certainly "grandiose" or "large scale" referred to by others. But I'd be happy with interplanetary directed panspermia after some of the ethical checks are made for existing life being considered by others, such as Clint, - just not to the extreme he is proposing.

clint
2010-Apr-12, 10:26 PM
Here we go again with the slanting of language, now its "large scale", another emotive use of language used to justify the previous one.
Not trying to justify anything Canis, your seeding project does sound large-scale.
And from the reaction of other posters here, it seems I was not the only one under that impression.

If you are thinking of smaller, more controlled experiments with extremophiles, OTOH, I actually like the idea.
PS: although I still fail to see why we cannot do those experiments much cheaper and faster back home?

IsaacKuo
2010-Apr-12, 10:40 PM
I knew a good idea just can't be kept down, except first up, I would concentrate on our solar system, not other ones.
The problem is that even extremophiles require liquid water conditions, and that's not very common here in the solar system. We believe there is liquid water deep within some moons, but we haven't checked out any of them yet.

For all we know so far, every place with liquid water is already teeming with life. These are the only places where your extremophiles would have even the slightest chance of surviving.

In contrast, developing space habitat technology does not require naturally occuring liquid water. Most of the water in the solar system is in solid ice form, which is perfectly fine for supplying artificial space habitats. Whether you like it or not, we have developed primitive space habitat technology, and we continue to develop it. We're advancing space habitat technology year after year, step by step. Only a fraction of this research is taking place in outer space, so you may not realize how much development there is.

clint
2010-Apr-12, 11:04 PM
The problem is that even extremophiles require liquid water conditions, and that's not very common here in the solar system [...] These are the only places where your extremophiles would have even the slightest chance of surviving.
And those are precisely the places we should be careful not to contaminate before we even get a chance to study them first.

Canis Lupus
2010-Apr-13, 05:45 AM
The problem is that even extremophiles require liquid water conditions, and that's not very common here in the solar system.

Extremophiles have been discovered in Anatartica embedded in rock, away from the surface, the driest place on earth.



We believe there is liquid water deep within some moons, but we haven't checked out any of them yet.

For all we know so far, every place with liquid water is already teeming with life. These are the only places where your extremophiles would have even the slightest chance of surviving.

Disagree, nor would I underestimate the ability of simple forms of life to adapt reasonably quickly.

Your belief is fine, but remember it is just that. Without evidence all you have is theory, wishful thinking, verging on a religious type of dogma, if, despite growing data that there is no life, one holds onto these beliefs. Carl Sagan was tremendous man who said and wrote many fine words, but when you see footage of him gamely holding onto hope that Venus has life, speculating almost irrationally where life could still be found on Venus despite all the data suggesting otherwise, one realises how much of a dreamer the man was. That's not to say he did not serve a useful purpose with his dreams in helping to motivate and inspire the public in favour of space exploration. Nonetheless, he represents quite vividly the type of dreaming which ultimately disappoints people and may leave more practical and affordable ideas unexplored.




In contrast, developing space habitat technology does not require naturally occurring liquid water. Most of the water in the solar system is in solid ice form, which is perfectly fine for supplying artificial space habitats. Whether you like it or not, we have developed primitive space habitat technology, and we continue to develop it. We're advancing space habitat technology year after year, step by step. Only a fraction of this research is taking place in outer space, so you may not realize how much development there is.

There is no reason, except funds, why the two cannot work hand in hand. The chances of directed panspermia succeeding would be be enhanced by a manned presence to get it started, although a more economical version would dispense with that presence. Therein lays the crux of the issue. We can do many things theoretically but underlying it all, apart from motivation and technology, is economics. You dream about these things, I share that dream, but most people who pay taxes and vote in politicians, don't share your enthusiasm once they begin to understand how expensive it all is and realise the extent of the opportunity cost here on Earth - how many hospitals it will mean doing without, how many roads don't get maintained properly, what defence compromises must be made, what school facilities must go unfunded etc.

Then there is the prospect of some disaster. Imagine the public's reaction if, after spending enormous funds on sending a colony of people to Mars, they died in transit or while on Mars - an event which is not that unlikely. Not only will it kill the people sent, it will kill funding the on-going expense of colonisation and future developments. There are people who would gladly volunteer for such missions despite the risks. Personally, I have ethical problems with taking advantage of their spirit with the risks involved.

We have problems just getting people into orbit safely.


And those are precisely the places we should be careful not to contaminate before we even get a chance to study them first.

How are you going to study them? Who is going to pay for all the research needed to study it to the extent to make sure they are sterile environments. Yes, do as much research as possible to understand the environments you aim directed panspermia at, replicate that environment here on earth as best as possible, and see which microbes stand a fighting chance in that environment, then send them away to their new homes. If they fail, no big disaster. If they succeed, the long term consequences are enormous - ET life has been discovered, has been started with potentially as much significance as just finding life out there.

I can't help but detect an environmentalist's approach with some of this thinking against the idea, a transference of the pristine wilderness idea here on Earth spaceward, and things must be kept pure away from Man's corruption. There is also the Hollywood or sci-fi influence at work. It's pretty hard to write a novel or make a film about microbes surviving and evolving slowly on an alien world. Remember sci-fi is just that - fiction. Gritty reality is another thing.

IsaacKuo
2010-Apr-13, 11:51 AM
Extremophiles have been discovered in Anatartica embedded in rock, away from the surface, the driest place on earth.
But only in liquid water conditions. The basic requirement is to live in places where the pressure and temperature is compatible with liquid water. Under those conditions, even the tiniest amounts of water seem sufficient for life.

But if the temperature is wrong (above boiling or enough below freezing to prevent anti-freeze from working), and/or the pressure is wrong (insufficient pressure for liquid water to exist), then life as we know it can't exist.

You vastly overestimate the capabilities of extremophiles.

Your belief is fine, but remember it is just that. Without evidence all you have is theory, wishful thinking, verging on a religious type of dogma,
All you have is wishful thinking, verging on a religious type of dogma.

There is absolutely no evidence, so far, that there is no life out there in the sorts of environments where we would expect life to exist.

We simply haven't looked any place where liquid water can exist, yet. Every place we've looked at so far has either had too little pressure (Mars, Moon), too much temperature (Venus), or too little temperature (Titan). Despite your belief, extremophiles would have absolutely no chance of surviving any of these places. The water in them would either freeze or boil.

The fact is, we just don't know how common or how rare life is, out there.

Canis Lupus
2010-Apr-13, 03:18 PM
You vastly overestimate the capabilities of extremophiles.

That's the point of seeing whether they can evolve. Now you are sounding God-like setting limits for life, and what can evolve. I don't know the limits of evolution. I'd say you are never going to find out unless exposure is allowed to different environments to test those limits. Adaption to a changed environment is one of the key elements to evolution.


All you have is wishful thinking, verging on a religious type of dogma.

Why is that, IsaacKuo - because you dogmatically assert it?


There is absolutely no evidence, so far, that there is no life out there in the sorts of environments where we would expect life to exist.

Except all the evidence that no life exists. There is a fallacy in your thinking because given the amount of galaxies in the universe - we are still counting-estimating ever upwards - there can never be proof there is no life out there, whether it be in places we expect or don't expect. It's an impossible proof to ask of anyone, but you use that standard to prevent practical measures to spread known life.

The other thing to note is your expectation. You seem to think Earth was once always like it is now. The earliest known life formed on Earth 3.9 billion years approximately, existed when it was very different to it is now, when it appears to have resembled Titan more than itself as it is now. Part of what caused Earth to change was life itself. It was a process of life changing the environment together with other factors, then life itself adapting to the changed environment. The process goes hand in hand. Without a changing environment, there would probably be no evolution.

What you have in these worlds are not only no signs of life, but no signs of changes consistent with life ever having been present or being present causing change, one of which may in fact be the existence of liquid water, being possibly a natural chemical result of life's influence on the environment.


We simply haven't looked any place where liquid water can exist, yet. Every place we've looked at so far has either had too little pressure (Mars, Moon), too much temperature (Venus), or too little temperature (Titan). Despite your belief, extremophiles would have absolutely no chance of surviving any of these places. The water in them would either freeze or boil.

The fact is, we just don't know how common or how rare life is, out there.

Or even that it exists, and can never know it doesn't. We could explore the Milky Way from side to side, top to bottom, find nothing, but it would still be open to make the same statement. It's meaningless to say such a thing in the context of the universe.

Do we have proof that there is no other life other than what is on earth in our solar system - no? Are all the indications consistent with the idea that there isn't - yes? It might take you hundreds or thousands of years to exhaust the possibility in the solar system.

But according to your reckoning, if we can't find liquid water, then that should be satisfactory enough. Is that right?

Besides, you are contradicting yourself. If these microbes cannot survive in the places you have mentioned, then that would act to prevent contamination, which was your original objection to the idea. Why should you object to others giving it a go on the worlds you mentioned on the basis of contamination then?

It doesn't make sense.

IsaacKuo
2010-Apr-13, 03:47 PM
That's the point of seeing whether they can evolve. Now you are sounding God-like setting limits for life, and what can evolve. I don't know the limits of evolution. I'd say you are never going to find out unless exposure is allowed to different environments to test those limits. Adaption to a changed environment is one of the key elements to evolution.
Life on Earth has had billions of years to try and evolve to survive in conditions where liquid water can't exist. It hasn't done so yet. Do you think that human experiments with putting extremophiles in such conditions are going to yield results within, say, mere millions of years?

We have really good physics and chemistry reasons to believe that the forms of life we see here on Earth can't survive in conditions where liquid water can't exist. Liquid water is pervasive in biochemistry (as we know it). The chemical reactions of life as we know it simply doesn't work without liquid water. Steam doesn't work. Ice really doesn't work.

Maybe life can exist without liquid water. I personally expect that artificial life will be developed which will do just fine without volatiles of any sort (just silicon, steel, etc). But there's no way for biological life as we know it to evolve away from the use of liquid water.

Except all the evidence that no life exists.
What evidence? We have barely even started looking for that evidence, and we have barely even scratched the surface.

The other thing to note is your expectation. You seem to think Earth was once always like it is now.
Nonsense.

The earliest known life formed on Earth 3.9 billion years approximately, existed when it was very different to it is now, when it appears to have resembled Titan more than itself as it now.
No. It resembled modern Earth far more than Titan. Even back then, there were liquid water oceans. The oldest rocks we can find include evidence of hydration.

What you have in these worlds are not only no signs of life, but no signs of changes consistent with life ever having been present or being present causing change, one of which may in fact be the existence of liquid water, being possibly a natural chemical result of life's influence on the environment.
If you're trying to suggest that life on Earth created the conditions for liquid water, then that would be severely ATM.

The non-ATM view is that Earth had the conditions for liquid water due to the amount of heating from the Sun. This meant that Earth's natural surface temperature was in line with what's needed for water to be in a liquid state.

Do we have proof that there is no other life other than what is on earth in your solar system - no? Are all the indications consistent with the idea that there isn't - yes?
Are all the indications consistent with the idea that there is? Yes!

You have a highly inflated idea of how much actual space exploration we've done and how much evidence we have gathered. The only planetary bodies which we have landed on are:

Moon - too little pressure (in the places we have investigated)
Mars - too little pressure (in the places we have investigated)
Venus - too hot (!!!!)
Titan - too cold (for life as we know it--but silicon based life might be possible)

Of the above, the only one which we can be rather confident is entirely dead is Venus. It's just too hot. The Moon and Mars might have underground liquid water, which might harbor life. It's possible that methane on Mars is generated by underground life. But we have just barely scratched the surfaces if the Moon and Mars, so we don't know.

Besides, you are contradicting yourself. If these microbes cannot survive in the places you have mentioned, then that would act to prevent contamination, which was your original reason for objection to the idea. Why should you object to others giving it a go on the worlds you mentioned, except you think they will be wasting their time?
Oh, if you want to personally waste your time and money, then sure.

But that isn't going to stop me from personally telling you that you're wasting your time and money.

It's not going to stop me from noting that it is not, in fact, a "good idea".

ravens_cry
2010-Apr-13, 06:23 PM
I think with a little genetic engineering certain extremophiles could be adapted to conditions elsewhere. But extremophiles are adapted to where they are. In many cases to them, we are the extremophile.

PraedSt
2010-Apr-13, 06:41 PM
Despite some optimistic views about other forms of life being out there, as yet there are no signs, just statistical speculations. I'm agnostic about the possibility, but live in hope. In the meantime, some thought about doing one of the things Man has been quite good at here on earth, but taken to a celestial level, wouldn't hurt - a form of space farming.

If I was given the task of finding life elsewhere other than Earth, I would cheat. Gather together extremophiles, plant them on moons and planets as best as possible to give them a head start, then let them adapt to the environment if they can; and, if they can, hope they adapt the environment they are in to evolve more complex forms of life, like life has here on earth.

The more places it is done, the higher the likelihood it would succeed. It has already been shown that microbes introduced to the moon by the Apollo missions were able to survive in a doormat state for several years. What would have happened if they were allowed to stay there undisturbed instead of bringing them back to earth is unknown, of course, but having seen how it could work through an accident, the occurrence does provide some inspiration or model for the possible seeding of life on other planets and moons on a very basic level, which involves minimal expense compared to the idea of colonisation by man.

It's a long long long term venture, but if it is Life which counts, does it matter that it is our form of life that goes out there, especially if there are more adaptable and resilient forms which could be given the task? We could be planting the seeds for a long term expansion of life throughout the universe although we may never be around to see its fruits.
The point of this directed panspermia is to promote Earth life (and not necessarily human life) across the Solar System, correct?

I have no qualms as such, as long as you (a) make a decent effort to find any natives and (b) stick some of what you find in a glass jar, before you introduce the competition. I think we humans would be better of in space habitats, so I tend to see planets as spherical mines.

But I think you might have a difficult time. There's a thread here by 99gecko (http://www.bautforum.com/showthread.php/101555-Protecting-Terraforming-Bacteria-While-They-quot-Work-quot) where he makes the excellent point that there is a big difference between organism survival and organism proliferation. Making your project succeed would take a lot of hard work and a lot of money.

clint
2010-Apr-13, 11:00 PM
I think with a little genetic engineering certain extremophiles could be adapted to conditions elsewhere.
Right, and that would be much easier, faster and cheaper to do here on Earth.

clint
2010-Apr-13, 11:29 PM
Disagree, nor would I underestimate the ability of simple forms of life to adapt reasonably quickly.
Isn't that contradictory? You think earthly extremophiles could survive and adapt beyond Earth,
but on the other hand no native life could have evolved in the rest of our solar system during 5 billions years?


How are you going to study them? By sending probes. There are already missions to investigate water on Mars and Moon (although I do agree that life on the Moon is extremely unlikely). There are mission plans for Europa, too.


Who is going to pay for all the research needed to study it to the extent to make sure they are sterile environments.
We are. And not just because there could be native life. Any water sources are also interesting for future manned missions.
Contaminating them with extremophiles would add a major health risk for any future explorers.


I can't help but detect an environmentalist's approach with some of this thinking against the idea...
Strawman. You keep repeating that any objection to your project is inspired by environmentalism, a "Greenpeace" mindset, excessive optimism, etc.
That's not very helpful in a debate (I suppose you are looking for a constructive debate?).
Just deal with the arguments.

ravens_cry
2010-Apr-14, 03:14 AM
Right, and that would be much easier, faster and cheaper to do here on Earth.
Of course. But we are still going to need to test them out there eventually, if they are planned for the use of seeding life.

neilzero
2010-Apr-14, 03:24 AM
I agree with the others: You should not do this, but I think you can with sufficient resources and somewhat advanced technology. The extremophiles are more likely to survive far below the surface, but they might evolve to modify the surface so their decendents can live there. Analog Science Fact, Science fiction carred at least one story about a man who lived alone on a huge seed ship, 1980 perhaps. Neil

Canis Lupus
2010-Apr-14, 03:36 AM
Right, and that would be much easier, faster and cheaper to do here on Earth.

Agreed. It is the best way to go, replicate conditions iif possible or as best as possible in the lab, then either selectively breed or genetically engineer the organism to survive. The Russians did this with their Venus probes once they had some idea of the atmosphere on Venus from their failed first probe, built a giant pressure cooker.

First stage would be to research conditions on other bodies and in doing so more information will become available on possible existing organisms, which is happening now to some extent. We have a pretty good idea of Martian atmosphere.


Isn't that contradictory? You think earthly extremophiles could survive and adapt beyond Earth,
but on the other hand no native life could have evolved in the rest of our solar system during 5 billions years?

No, because I think it is possible that other natives could exist and evolve in the rest of the solar system. I'm still hopeful there will be such a discovery, but all evidence so far points to it not being the case. The issue I have with your stance was your wording "make sure". That level of certainty isn't possible, not cheaply at least, and certainly not in any foreseeable future. In fact, I don't know how you could ever attain that standard. Any suggestions?

We don't send people into the space with that level of certainty of coming back. I see no need to be applying it to finding life which may exist elsewhere than earth. If there is evidence pointing to life, that is a different matter, but so far all we have is a big fat naught on that score.

Besides that, there is a difference between life evolving and life originating. Once it originates, evolution may happen quite quickly, or once a critical point is reached, happen quite quickly, if Earth is a guide, it being the only example we have thus far of course. If we look around at our solar system by contrast, the problem may well be in the originating, not evolving, although that is not straight forward either.

I lean towards the restriction being in the originating. Until we can explain the origins of life, all we are left with is piecing together evolution. Assuming for one moment that no life exists in the Solar System outside of earth, there are several possible explanations, one of which is the Goldilocks idea. While that idea might be useful in narrowing a more distant search for life, I suspect life is more flexible and durable than needing a Goldilocks world. That is the hope with Europa to some extent.

In applying the idea of evolution as we understand it one needs to keep in mind the second side of the evolutionary equation which is not often mentioned, that, life not only adapts to the environment, but the environment becomes changed by life. It's even possible that life is changing the environment to its own end in much the same way that the organisms themselves change.

robertgrzeda
2010-Apr-14, 09:50 AM
I am wondering if it is possible to happen something like this:
A man stand on the moon (or some planet) and leave there some bacterias by accident. Then there were absolutely no human's activity on this planet (or moon) for a dozens of years. And then some expedition was sent onto this planet and... the bacterias left before evolved and now there is some new life on the planet. What do you think - is this possible?

99gecko
2010-Apr-14, 04:02 PM
Okay,
Since my name was dragged into this thread earlier, I thought I'd make a couple of points.


Yes, do as much research as possible to understand the environments you aim directed panspermia at, replicate that environment here on earth as best as possible, and see which microbes stand a fighting chance in that environment, then send them away to their new homes. If they fail, no big disaster. If they succeed, the long term consequences are enormous - ET life has been discovered, has been started with potentially as much significance as just finding life out there.
Just a clarification first. No, ET life would not have been discovered. ET life, by it's very definition, is life of an origin other than from planet Earth. The fact that it may or may not have evolved since leaving Earth does not negate the fact that it is Terrestrial in origin.

Secondly, I don't think you have fully contemplated the ethics component:

There is a possibility we won't be around to be doing what your morals have problems about once the ecology gets going, but assuming we are, isn't it like planting trees for harvest or breeding cattle for food? If we are the ones responsible for the ecology in the first place, I say it gives us a certain discretion, however, there is no need to see Man in opposition to the organisms or potentially evolving ecology.
To say that it would resemble harvesting or breeding is simplistic. I'm not saying that I disagree or agree with you. Simply that I suggest that there will be comparisons made to genetically modified organisms (GMO's) being used for food/medicine, and also to human cloning. Both processes could be classified as "harvesting", but have a persistent ethical backlash. To dismiss this as a non-issue is optimistic at best, but more likely foolhardy than not.
Again on the point of ethics, but with regards to seeding a planetary body that has not been confirmed to be sterile, I suggest a thought experiment for your contemplation:

Consider the scenario where an alien species, intelligent in it's own right, has identified our planet Earth as having some resource which it deems necessary for it's survival, or for some seeding experiment of it's own. Yet for some reason this species is either incapable of immediately detecting the life that is already here, or can detect it, but decides it is irrelevant or a source of interference to it's goals. Should this species be allowed to sterilize the Earth? Can we transfer our ethics to an alien life form, merely because we were here first? So, how do we protect ourselves? So how do we allow a pre-existing live form provide evidence of it's existence on another planetary body prior to seeding it, potentially destroying it? There is a huge list of questions that can be generated from this scenario. The ones I mentioned above are the most basic. I think the best approach is has been mentioned elsewhere: do your experiments here, using data generated from exploratory probes. I'll tell you as a biochemist, that we do not need to leave our backyard to study evolutionary processes. To me, the requirement that we seed other planetary bodies to do the experiments is unnecessary. Panspermia is not about testing to see if life can evolve off our planet. Panspermia, as I see it, is about transmitting our life structure beyond our originating planet, with or without ever knowing of it's outcome.


In applying the idea of evolution as we understand it one needs to keep in mind the second side of the evolutionary equation which is not often mentioned, that, life not only adapts to the environment, but the environment becomes changed by life.
I don't understand what you are stating. You can't open a newspaper without seeing the phrases toxic spill, carbon footprint, or emissions control.

Sorry, but I just don't seem to understand your urgency. Technology will allow us to catch up with our dreams, but we must be patient.

Just a side note on extremophiles and polyextremophiles. The characteristics that give these archaea the ability to tolerate conditions, which we as humans consider extreme, invariably come at a cost to the organism. This cost can be in various forms: additional energy expenditure, exceptional required resources, environmental/metabolic restriction, reduced metabolism/replication/lateral gene transfer (reduces ability to mutate)/mobility/etc. I might also add that the ability to adapt to an environment should not be considered inevitable. Just because we see it here on Earth occasionally, does not mean it would be ubiquitous throughout the universe.

cheers.

99gecko
2010-Apr-14, 04:12 PM
A man stand on the moon (or some planet) and leave there some bacterias by accident. Then there were absolutely no human's activity on this planet (or moon) for a dozens of years. And then some expedition was sent onto this planet and... the bacterias left before evolved and now there is some new life on the planet. What do you think - is this possible?
Absolutely possible. However, any bacteria left there by accident, must have environmental conditions that will allow it to flourish to evolve. That may not be the case. In the example of our own solar system, it is highly unlikely. Evolution, whatever mechanism it uses, requires reproduction. Reproduction typically occurs under favorable conditions. Please do not forget that extinction is another possible outcome of evolution.

clint
2010-Apr-14, 11:27 PM
The issue I have with your stance was your wording "make sure". That level of certainty isn't possible, not cheaply at least, and certainly not in any foreseeable future. In fact, I don't know how you could ever attain that standard. Any suggestions?
Ok, I see. I wasn't really thinking of "100% sure there is no native life" - I agree that is almost impossible to prove.
The thing is, until now we haven't even got the chance to take a closer look at those places where we suspect water beyond Earth.

I wouldn't have a problem with flexible standards, e.g. as a function of increasing likelihood of native life):
- on the moon, I would treat water as a resource for future missions. Go ahead and use it.
- on Mars, let's first have a closer look - at least where there is any chance of liquid water.
- on Europa, however, I would indeed put the whole moon under quarantine and only let in sterile probes for the foreseeable future
(at least until we got the chance to really investigate the underground oceans - and if it's only near as big as we think it might, that will take more that just one probe and longer than our lifetime)

clint
2010-Apr-14, 11:30 PM
Please do not forget that extinction is another possible outcome of evolution.
The by far most likely outcome, yes. More than 99% of earthly species go down that road.

Canis Lupus
2010-Apr-16, 04:04 AM
... I don't think you have fully contemplated the ethics component:

To say that it would resemble harvesting or breeding is simplistic. I'm not saying that I disagree or agree with you. Simply that I suggest that there will be comparisons made to genetically modified organisms (GMO's) being used for food/medicine, and also to human cloning. Both processes could be classified as "harvesting", but have a persistent ethical backlash. To dismiss this as a non-issue is optimistic at best, but more likely foolhardy than not.

Again on the point of ethics, but with regards to seeding a planetary body that has not been confirmed to be sterile, I suggest a thought experiment for your contemplation:


Consider the scenario where an alien species, intelligent in it's own right, has identified our planet Earth as having some resource which it deems necessary for it's survival, or for some seeding experiment of it's own. Yet for some reason this species is either incapable of immediately detecting the life that is already here, or can detect it, but decides it is irrelevant or a source of interference to it's goals. Should this species be allowed to sterilize the Earth? Can we transfer our ethics to an alien life form, merely because we were here first? So, how do we protect ourselves? So how do we allow a pre-existing live form provide evidence of it's existence on another planetary body prior to seeding it, potentially destroying it?

There is a huge list of questions that can be generated from this scenario. The ones I mentioned above are the most basic. I think the best approach is has been mentioned elsewhere: do your experiments here, using data generated from exploratory probes. I'll tell you as a biochemist, that we do not need to leave our backyard to study evolutionary processes. To me, the requirement that we seed other planetary bodies to do the experiments is unnecessary. Panspermia is not about testing to see if life can evolve off our planet. Panspermia, as I see it, is about transmitting our life structure beyond our originating planet, with or without ever knowing of it's outcome.

I agree with you to some extent although I do not want to get involved in discussing the theoretical example you propose. The last sentence, the part I have additionally underlined is particularly where I agree with your thoughts. Start the life process off, then let it do what it does best, work out unique and imaginative ways of surviving. Where and what it ends up evolving into is anyone's guess and like many things in nature, my guess is, it will end up surprising and educating us if we are around to see the fruits.



I don't understand what you are stating. You can't open a newspaper without seeing the phrases toxic spill, carbon footprint, or emissions control.

That's quite a different way of looking at life changing the environment as an integrate and necessary part of evolution. The underlying message in the context you mention is to prevent change, not accept it. The implication of that type of change is that it is life threatening and anti-evolutionary, which highlights the point I originally made that the second half of the overall evolutionary equation is rarely mentioned - change in the environment has been necessary for evolution to occur and that life itself has contributed substantially to the change.


Sorry, but I just don't seem to understand your urgency. Technology will allow us to catch up with our dreams, but we must be patient.

I don't see any urgency. It's not something I feel particularly strong about although I'd be concerned if it doesn't start being prepared for in the next 20-30 years or so, it will probably never happen, not directed panspermia or even the more accepted space colonisation of man. Political imperatives will always take precedent. Landing on the moon was motivated by the Cold War at a political level, otherwise it probably would not have occurred. The folks directly involved in achieving these things do so from a genuine heart felt interest, but the ones paying the bill for it all, need other motivations which tend to be more fickle it seems. Even now, funding is on the decline. That might change in a different economic environment, but I foresee a growing lack of interest in wider space exploration, unless it can some way be demonstrated to give someone an economic or military advantage here on earth. Otherwise, if one is going to appeal to an ideal, it needs to be cheap.

Kevinanchi
2010-May-03, 12:17 PM
Hi, I agree with u...

clint
2010-May-06, 11:41 AM
Hi, I agree with u...

With whom? Why, how and where? ;)

marsbug
2010-May-06, 11:32 PM
Absolutely possible. However, any bacteria left there by accident, must have environmental conditions that will allow it to flourish to evolve. That may not be the case. In the example of our own solar system, it is highly unlikely. Evolution, whatever mechanism it uses, requires reproduction. Reproduction typically occurs under favorable conditions. Please do not forget that extinction is another possible outcome of evolution.

I'm not sure I'd simply class it as highly unlikely; there are a lot of water ice and carbon rich places out there that could get visited. Many worlds in our solar system that are currently unlivable to anything seem to have experianced brief, localised, episodes where all the basic conditions for habitability (liquid water, warmth, carbon) have been present. Brief in this context can mean centuries, or even millenia, and dormant microbes can be incredibly hardy. I think that what robertgrzeda suggests is unlikely for any single microbe or world, but entierly possible if a lot of contamination is spread about the solar system.

Boratssister
2010-May-10, 10:47 PM
Would not earths etremephiles already have spread around the solar system due to comet inpacts?
We have martian meteorites here on earth, there must be bits of earth already on mars and floating around our region of the galaxy. How far can a spec of dust/ice travel in 3.9 billion years?

Canis Lupus
2010-May-11, 04:51 AM
Would not earths etremephiles already have spread around the solar system due to comet inpacts?
We have martian meteorites here on earth, there must be bits of earth already on mars and floating around our region of the galaxy. How far can a spec of dust/ice travel in 3.9 billion years?

One would think there would be some, but it would also seem sensible to think that there would be less originating from Earth than from Mars because of Earth's greater gravity and atmosphere. If, on the other hand, one subscribed to the Expanding Earth theory, this would have been less difficult during Earth's early history, and possibly even Mar's if the idea of expansion can also be applied there.

marsbug
2010-May-11, 10:26 PM
Would not earths etremephiles already have spread around the solar system due to comet inpacts?
We have martian meteorites here on earth, there must be bits of earth already on mars and floating around our region of the galaxy. How far can a spec of dust/ice travel in 3.9 billion years?

A long way, but the course is random, so the average travel time before landing is likely to be hundreds of thousands of years or more. Of course if you have a huge impact and millions of tons of earth material go into space then there may be a few that make the journey much faster, as well as some that are still wandering when the sun goes out.
Any passengers have to endure launch by asteroid/comet impact, a long time dormant in space, and survive landing. Then they have to survive on the surface long enough for a window of habitable conditions to come along.

Almost certainly some of earths extremophiles have made the trip, but I think it's an open question as to whether any have made it in fit state to reproduce, and had an opportunity to do so before death found them in some guise or other.

By comparison an astronauts boot is taking the luxury route.

A.DIM
2010-May-21, 12:06 AM
Would not earths etremephiles already have spread around the solar system due to comet inpacts? We have martian meteorites here on earth, there must be bits of earth already on mars and floating around our region of the galaxy. How far can a spec of dust/ice travel in 3.9 billion years?

Here's a recent paper Mechanisms for Panspermia (http://journalofcosmology.com/Panspermia4.html) which you might find illuminating.
As for me, I fail to view the Earth, or the solar system, or even the MW, as a closed system, an island isolated. There are mechanisms by which life can, and probably does, spread throughout the universe. And as you note, we're finding extremophiles which seem rather suited for space travel... which is weird.
Any way, my two cents.

Boratssister
2010-May-21, 05:22 PM
Here's a recent paper Mechanisms for Panspermia (http://journalofcosmology.com/Panspermia4.html) which you might find illuminating.
As for me, I fail to view the Earth, or the solar system, or even the MW, as a closed system, an island isolated. There are mechanisms by which life can, and probably does, spread throughout the universe. And as you note, we're finding extremophiles which seem rather suited for space travel... which is weird.
Any way, my two cents.

Thankyou adim.
Earlier in this thread I said I would be more confident of life elsewhere if we could create it here on earth . Well its just been achieved , maybe not 100percent synthetic but nether the less, life has been created. I was 50-50 on life existing elsewhere now I'm 90-10 in favour. Hope hawkins is wrong about them!

Canis Lupus
2010-May-22, 03:56 AM
Thankyou adim.
Earlier in this thread I said I would be more confident of life elsewhere if we could create it here on earth . Well its just been achieved , maybe not 100percent synthetic but nether the less, life has been created. I was 50-50 on life existing elsewhere now I'm 90-10 in favour. Hope hawkins is wrong about them!


Beg to differ that life has been created, although that was certainly the headline. It wasn't even close to 100%, it being either something that is created or isn't. What was done was entirely different to "creating" life, unless one includes having a baby as creating a life. They manipulated an organism's DNA, transplanting it into another's. They didn't create life.

Boratssister
2010-May-22, 11:36 AM
Beg to differ that life has been created, although that was certainly the headline. It wasn't even close to 100%, it being either something that is created or isn't. What was done was entirely different to "creating" life, unless one includes having a baby as creating a life. They manipulated an organism's DNA, transplanting it into another's. They didn't create life.

The d.n.a was synthetic, the cell was dead now its alive. They coppied nature I agree but the fact that we can create d.n.a makes the possibility of this happening here and elsewhere in the universe naturally a lot more likely. Its only a matter of time that computer designed cells will be completely synthetic. If we can do it then life is not as hard to get going as I first thought.

FarmMarsNow
2010-May-22, 05:33 PM
I'm starting to think that earth cells aren't going to do a good job on other rocks in our solar system, so I think its time to put the idea of farming Mars off many years into the future. If there ever was something alive on Mars, perhaps it can be reanimated. Short of that, what Mars requires is a slower more stable form of life than what earth cells are used-to. Assuming its a dead planet, then to introduce useful water-based life we'll need to warm up the planet first.

Relative
2010-May-23, 11:18 AM
I guess, considering the question of whether there is alien life out there already or not (and, therefore, whether some would call this contaminating it or not in seeding extremophiles or even smaller building blocks like DNA throughout the universe) one basic phenomenon isnt taken into account yet: that is atomic or molecule geometry exhibited under comparable conditions.

Element aluminium for example crystalizes in a face-centered cubic lattice, independent from whether it was found on earth or on a meteorite. And so do molecules arrange in the same way, if they have been formed under same conditions. The geometry is obviously somehow determined by subatomic structure and interacting forces pointing into specific directions between single atoms already.

So, sooner or later under comparable extraterrestial conditions, atoms will automatically arrange in the same structure. Formation of molecules like amino acid may, therefore, just may be a matter of time.
If this assumption is correct, we dont need to seed out life, because it will already be there. If this assumption is incorrect and some other influence additionally is neccessary to make a dead molecule become alive, we DO NEED to go great lengths to keep this life alive whether or not there may be alien lifeforms to which this influence happened as well, as they must be considered to be somehow relatives of us then, who will agree on that in terms of this procedure raises the overall odds.

As we dont know by now whether a molecule like DNA under certain conditions automatically becomes alive and what conditions these are, we will only be able to proceed in no other way than what we know or assume to know: That amino acids came to us in a period where planet earth was in a developping stage. This obviously worked out. So, if we are looking for those planets/moons in a comparable situation and sending our amino acids over there, we (better: life itself) might succeed. Sure, life probably would have arised there on its own without our influence. The outcome may be hybrid. Yes, but that is no contamination - that’s life!