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ocpaul20
2009-Mar-01, 04:43 AM
One thing that concerns me is that as soon as we start to visit non-earth locations we will start to take our bugs - viruses, bacteria etc and larger organisms with us. These bugs might survive to infect the local environment or they might die - who knows, and it seems like no-one cares either.

I realise that NASA probably try to make sure that things dont get into the spacecraft but this is unrealistic and we are bound to take some of our organisms with us when we go.

Basically what I am saying is that we will be the equivalent of the Martians in War of the Worlds. We will be the invaders, we will be subject to and exposed to the bugs of all kinds that live on other planets. We have no immunity to these bugs and so it is likely that we will suffer strange diseases. We have spent thousands of years evolving with our native bugs and becoming immune to most of them, and as soon as we arrive on foreign planets we have to start all over again and so we are likely to become infected by them.

I suspect this is a natural safety system that prevents other beings from colonising our 'home' and us colonising other race's 'homes' too. In order to overcome this kind of protection system we would probably have to embark on a series of genetic engineering projects to mutate ourselves so that we are immune to their bugs.

Do you think it is realistic to visit and try to colonise the Moon and Mars?

article about Building a Moon Base (http://www.universetoday.com/2008/02/07/building-a-base-on-the-moon-challenges-and-hazards/) although I have not got to the point where they discuss these things yet.

Peter B
2009-Mar-01, 05:08 AM
One thing that concerns me is that as soon as we start to visit non-earth locations we will start to take our bugs - viruses, bacteria etc and larger organisms with us. These bugs might survive to infect the local environment or they might die - who knows, and it seems like no-one cares either.

What makes you think no one cares? Anyway, I think you're wrong, and on two counts. More below.


I realise that NASA probably try to make sure that things dont get into the spacecraft...

That's the first place where your first paragraph is wrong. NASA, and other agencies, do try to sterilise craft going to Mars. Or at least, that's what they're doing with unmanned spacecraft. So how can you say they "don't care"?


... but this is unrealistic and we are bound to take some of our organisms with us when we go.

Well, there's another side to this...


Basically what I am saying is that we will be the equivalent of the Martians in War of the Worlds. We will be the invaders, we will be subject to and exposed to the bugs of all kinds that live on other planets. We have no immunity to these bugs and so it is likely that we will suffer strange diseases. We have spent thousands of years evolving with our native bugs and becoming immune to most of them, and as soon as we arrive on foreign planets we have to start all over again and so we are likely to become infected by them.

I suspect this is a natural safety system that prevents other beings from colonising our 'home' and us colonising other race's 'homes' too. In order to overcome this kind of protection system we would probably have to embark on a series of genetic engineering projects to mutate ourselves so that we are immune to their bugs.

My understanding is that the chance of a Mars bug infecting humans is very low, simply because any Mars bugs either have no relationship to Earth life, or at best have a most recent common ancestor dating back more than a billion years. Either way, Earth organisms and Mars organisms are likely to be so different that there's unlikely to be any mechanism whereby Mars bugs could infect Earth life. It'd be like trying to open a padlock with a car key.


Do you think it is realistic to visit and try to colonise the Moon and Mars?

Yes, but marginal and expensive. The one thing we don't need to worry about on the Moon is bugs - that place is dead as a proverbial. It's also relatively near to the Earth, so the turnaround travel time isn't large. But in the case of either the Moon or Mars, the question is what colonists would do. The only realistic way to make a go of such colonies is if they can produce exports of some sort. I'm not sure what either could export to the Earth in the short to middle term. Helium-3 is apparently a viable export from the Moon, but we have no technology at the moment to use it (it could be used in fusion reactors).

Murphy
2009-Mar-01, 05:26 AM
An interesting subject, in fact we were just having a similar discussion in this thread... http://www.bautforum.com/life-space/85348-human-bacteria.html.

Firstly I don't think this is an issue for the Moon, as there is almost certainly no possibility of native life there, and any Earth organisms could definitely not survive on the surface.

As for Mars, contamination of Earth microbes may be an issue, but NASA has so far been pretty scrupulous at sterilising anything they send down there. However, it would require a very hardy Earth bug indeed to live on Mars, but there may be a few species that could just about survive though.

Personally I think we would have to confirm whether there is any native life of Mars before attempting to deliberately release any Earth life there (i.e. for any possible Terraforming project). But at the moment at least, Martian life seems unlikely. So in the end, it may not matter.

As for the issue of Alien diseases, I think this is of less concern (at least if we are talking about our solar system). You point out that Humans have had to evolve immunities over millions of years, to the many microbes that try to attack us on Earth, and that is indeed true. But, what you forget is that the microbes have had to take just as long to evolve to be able to live inside our bodies and infect us. An alien bug would never before have encountered a Human and might not be able to infect us at all. There's also the factor that our very basic biology may be too different to their's, thus they might be totally harmless to us.

Consider the possibilities, our bodies may be too salty, or too acidic, or too hot, or too cold for alien bacteria. For instance if there were life on Mars it would likely be adapted to very cold, dry conditions and might thus find the warm and sticky inside of the Human body a very unpleasant environment.

Our immune system is also not as bad as you might think, it automatically attacks any "foreign body" within us, it has a simple system of recognising "self" form "non-self", and it tries to destroy anything non-self. So, even if our bodies had never before encountered a certain alien bug, our immune system would still recognise it as a threat and try to eliminate it.

Alien viruses would most likely be no problem at all, as viruses are very specific. They use certain molecules on their outer surface to attach to and gain entry to a cell and then multiply and burst out to infect other cells. But if the virus does not have the exactly correct surface molecules it cannot enter the cells and can do no harm. This is the case with the vast majority of viruses today, they can infect only a single species and are completely adapted to that. For instance generally if you have a virus you cannot spread it to your pet dog, and vice versa, because a virus adapted for Human cells is ineffective against a dog's cells, etc. (there are of-course some rare exceptions of viruses that can jump species and mutate though).

It seems highly improbable that an alien virus (were such a thing to exist) would be any danger to people, as it would be so highly specialised to pray upon alien organisms, that it would have no way of infecting us. There is of-course the possibility that the virus could mutate to try to infect us, but the biological gap between us and any alien lifeform would be so great as to make this very unlikely, if not impossible.

Peter B
2009-Mar-01, 05:36 AM
Thanks Murphy, you said what I meant to say, but much more eloquently.

ocpaul20
2009-Mar-01, 06:06 AM
Personally, I think there is so much 'wishful thinking' here that it positively scares the hell out of me.

Consider avian flu, CJD, and all the other viruses and bacteria that we have hidden away in our bioengineering labs such as ebola etc cowpox/smallpox etc

There are thousands of bacteria that live in inhospitable places such as deserts and deepsea fumes. This is one way that life may have started on earth, so to say that it is unlikely that they will mutate or be able to infect us is at best hopeful.

I say that NASA do not care because of the experiment they ran with the Surveyor 4 spacecraft they sent to the moon to test aging of materials. They state in their web site that they did not steralise it (thereby letting all kinds of things loose on the moon) before they sent it and then they tested the parts returned by Apollo crew members for bacteria etc.

the web page (http://www.lpi.usra.edu/lunar/missions/apollo/apollo_12/experiments/surveyor/)


A particularly important aspect of the Surveyor 3 analysis was the search for living material on the spacecraft. Surveyor was not sterilized prior to launch, and scientists wanted to know if terrestrial microorganisms had survived for two and a half years in space. One research group found a small amount of the bacteria Streptococcus mitis in a piece of foam from inside the TV camera.

The trouble is with these things that once it is done, there is no going back - rather like the rabbit released into Australia or the various pests that find their way to foreign countries. They breed and colonise far more effectively than we can.

Gillianren
2009-Mar-01, 07:08 AM
There are thousands of bacteria that live in inhospitable places such as deserts and deepsea fumes. This is one way that life may have started on earth, so to say that it is unlikely that they will mutate or be able to infect us is at best hopeful.

But they started on Earth. The distinction you are not seeing is that it's relatively easy for a microorganism of Earth ancestry to evolve to infect an animal of Earth ancestry. There are known mechanisms developed over a billion years and more. Sure, new ways evolve. But they are not, in fact, terribly different from old ways. A lot of microorganisms and viruses that infect humans enter, say, through the mucous membranes. But if a microorganism is from a planet where there are no creatures with microorganisms with mucous membranes, it's going to take more than a couple of generations for them to evolve an entry system akin to, oh, the common cold.


I say that NASA do not care because of the experiment they ran with the Surveyor 4 spacecraft they sent to the moon to test aging of materials. They state in their web site that they did not steralise it (thereby letting all kinds of things loose on the moon) before they sent it and then they tested the parts returned by Apollo crew members for bacteria etc.

So . . . they let microorganisms loose on a desert world with no atmosphere and constant bombardment by all sorts of cosmic bombarders, and you're saying that means that NASA is totally oblivious to the prospect of what alien microorganisms could do to us or other lifeforms? You do realize that there is no evidence of alien lifeforms on the Moon, right?


The trouble is with these things that once it is done, there is no going back - rather like the rabbit released into Australia or the various pests that find their way to foreign countries. They breed and colonise far more effectively than we can.

It is frankly not possible for a majority, possibly even all, of Earth microorganisms to breed on the Moon, and probably not on Mars, either. They don't all require oxygen; that's certainly true. But they do, for example, all require water. You're not going to get that anywhere on the Moon where humans or their equipment have been.

Van Rijn
2009-Mar-01, 07:51 AM
Regarding Surveyor 3, it's now generally thought that it was post-flight contamination. See, for intance, "Ask an Astrobiologist" (http://astrobiology.nasa.gov/ask-an-astrobiologist/question/?id=2701)



Yes, this microbe [streptococcus] was found on the Surveyor 3 camera that was retrieved and returned to Earth by the Apollo 12 astronauts. For many years it was thought that these microbes had survived their long exposure on the lunar surface. More recently, however, scientific opinion has shifted, and now we think these were probably contaminants introduced when the camera was retuned to Earth. It is very difficult to control such contamination, which is a cautionary tale for future return of samples from Mars. We don't want to identify life in such a sample and then be unsure if the life is from Mars or from Earth. David Morrison
NAI Senior Scientist
February 14, 2008


Even if bacterial spores did survive on the moon, there is a big difference between bacteria existing for a bit as spores (essentially in suspended animation) and physically growing. If you look at the recent probes that go to Mars and other worlds where there is some small chance that Earth life could grow, there is much more care being taken not to cause contamination. Also, in a proposed Mars sample-return mission I recall reading about, preventing the possibility of reverse contamination was a major consideration. So, I don't think this is an issue that's being ignored at all.

Now, when we do get around to sending astronauts to Mars, we'll have to think carefully about the possibility of contamination. While they could exercise some care, they couldn't be sterilized anywhere near the level of robot spacecraft.

ocpaul20
2009-Mar-01, 09:16 AM
Now, when we do get around to sending astronauts to Mars, we'll have to think carefully about the possibility of contamination. While they could exercise some care, they couldn't be sterilized anywhere near the level of robot spacecraft.There is no difference between Mars and the Moon and possibly other pieces of rock out there will have water and their own microbes too.

Currently NASA tell us that there IS water on both bodies and CO2 on Mars. This means that the possibility exists that microbes and spores that travelled on our spaceships or even on asteroids could set up camp there.

The point I am making is that 1) we have to be careful what we catch when we go there, and also 2) what we take there with us.

Maybe you honestly believe that space is as totally devoid of bugs as it is of aliens, but I think this subject is far more long-term life threatening in a hostile environment than the subject of what we build our moon/mars bases out of.

The article I linked to above did not even mention the contamination/microbe hazzard problem, but went on about how we should protect ourselves from meteors and what to make building from when there is no atmosphere.

The other point I would like to make is that USA may have steralised their spaceships but other countries have also sent spaceships out there and their priorities may be different and sterilisation techniques may not be as good.

ocpaul20
2009-Mar-01, 09:22 AM
But they started on Earth. Not at all necessarily. I believe plenty of microbes come from meteorites, dont they? How do completely new strains of microbe suddenly appear? Maybe they mutate, maybe they hitch a cosmic ride on a rock travelling from somewhere. Perhaps a different wavelength of solar radiation suddenly breaks them out of a long-dormant spore stage? We dont know all the possibilities and it is virtually impossible to trace a strain back to its origin.

eburacum45
2009-Mar-01, 09:26 AM
Mars may be full of bugs; in fact I hope it is (although somehow I doubt it). But they will be evolved to live in such a dry, cold environment that our warm wet bodies will be almost certain death for them. The chances that anything exists there now that can attack us is almost non-existent.

Mind you, if Mars does hold an evolving biosphere, perhaps some martian bug might evolve to attack us after we've been living there in colonies for a while; but I can't see why it need be more virulent than anything found on Earth.

Peter B
2009-Mar-01, 10:04 AM
There is no difference between Mars and the Moon and possibly other pieces of rock out there will have water and their own microbes too.

There are significant differences between the Moon and Mars. Most importantly, the Moon has no atmosphere. As one scientist put it at the time of Apollo 11 (sorry I can't find a link), he couldn't think of a more effective sterilising environment than the surface of the Moon. No life of any sort was found on the Moon.


Currently NASA tell us that there IS water on both bodies and CO2 on Mars. This means that the possibility exists that microbes and spores that travelled on our spaceships or even on asteroids could set up camp there.

Water on the Moon exists most likely as ice from comets which have crashed in permanently shadowed craters. It would never have existed as a liquid. The Moon itself was likely waterless from its origin. This is not an environment in which life could evolve.


The point I am making is that 1) we have to be careful what we catch when we go there, and also 2) what we take there with us.

Fair enough.


Maybe you honestly believe that space is as totally devoid of bugs as it is of aliens, but I think this subject is far more long-term life threatening in a hostile environment than the subject of what we build our moon/mars bases out of.

But the point is, as others have said, that any creatures which evolved in a completely separate environment, and have had no contact ever with any life from Earth, would have no mechanism for infecting us. If you're thinking that life from completely separate environments can interact in a meaningful way, say, like Klingon-Human half-breeds in Star Trek, then you're completely wrong. The idea of a Mars-evolved bug infecting a human would be like a human and an oak tree producing offspring.


The article I linked to above did not even mention the contamination/microbe hazzard problem, but went on about how we should protect ourselves from meteors and what to make building from when there is no atmosphere.

That's because, on the Moon, microbes are not an issue. The only microbes there we will have brought there from Earth.


The other point I would like to make is that USA may have steralised their spaceships but other countries have also sent spaceships out there and their priorities may be different and sterilisation techniques may not be as good.

Well, you may have a point, but do you have any specific evidence?

Van Rijn
2009-Mar-01, 10:12 AM
There is no difference between Mars and the Moon and possibly other pieces of rock out there will have water and their own microbes too.


No, there's a pretty big difference depending on the environment of the world. It does help, for example, to have water, so we'll move on to your next statement . . .



Currently NASA tell us that there IS water on both bodies and CO2 on Mars.


In fact the moon is extraordinarily dry - ridiculously dryer than the driest Earth desert. NASA hopes there is a very little frozen water in permanently shaded polar craters, but so far it hasn't been looking very promising. And it doesn't do well in a lot of other chemicals needed for Earth life either. Mars does a bit better. It still is a very unlikely place to find life that would "like" us, but it's far, far more likely than the moon.



The point I am making is that 1) we have to be careful what we catch when we go there, and also 2) what we take there with us.


Well, on that I don't think you'll get much argument from the mission planners, though they do look at what environments just might be able to support some Earth life and what can't. So, for instance, they are going to consider Mars more closely than the Moon or, say, Mercury.

ocpaul20
2009-Mar-01, 10:30 AM
Well, you may have a point, but do you have any specific evidence?How can I say that one country is more laid back about their cleanliness requirements? It is obvious isn't it?

Please dont get hung up on this evidence thing and ask for it all the time. I am not going to name names just to give evidence. If you think what I say is not common sense then, of course, say so.

We are assuming that life in the universe is based on water, but that may not be a fact. We are currently only looking for water-based life which in my opinion is fairly stupid, and is a fairly narrow-minded approach to alien/off-world life.

We have to begin to think outside the Earth-based science box and realise that if life has evolved around water here, it does not mean it has to evolve around water on a different planet - even in our own solar system.

BetaDust
2009-Mar-01, 10:46 AM
How can I say that one country is more laid back about their cleanliness requirements? It is obvious isn't it?



How can you?




Please dont get hung up on this evidence thing and ask for it all the time. I am not going to name names just to give evidence. If you think what I say is not common sense then, of course, say so.



Ok. I think what you say is not common sense.




We are assuming that life in the universe is based on water, but that may not be a fact. We are currently only looking for water-based life which in my opinion is fairly stupid, and is a fairly narrow-minded approach to alien/off-world life.



Why is it "in your opinion" fairly stupid?




We have to begin to think outside the Earth-based science box and realise that if life has evolved around water here, it does not mean it has to evolve around water on a different planet - even in our own solar system.

I Think a lot of people are doing that allready.



--Dennis

Van Rijn
2009-Mar-01, 10:50 AM
How can I say that one country is more laid back about their cleanliness requirements? It is obvious isn't it?

Please dont get hung up on this evidence thing and ask for it all the time. I am not going to name names just to give evidence. If you think what I say is not common sense then, of course, say so.


Folks have a habit of asking for evidence of claims on this board, and "common sense" has a habit of being wrong. :)



We are assuming that life in the universe is based on water, but that may not be a fact. We are currently only looking for water-based life which in my opinion is fairly stupid, and is a fairly narrow-minded approach to alien/off-world life.

We have to begin to think outside the Earth-based science box and realise that if life has evolved around water here, it does not mean it has to evolve around water on a different planet - even in our own solar system.

And so, there just might be life that doesn't use water on another world. But, if there is no water on that world, Earth life still won't survive there. And, being radically different life from that on Earth, it would have little in common with Earth life and would be extremely unlikely to be a threat.

Peter B
2009-Mar-01, 11:00 AM
The idea of using the search for water as the basis for a search for life elsewhere isn't narrow-minded or stupid. There are very good reasons for assuming that water is vital to life anywhere, because of its use as a solvent and because it's used to break down and build up organic molecules. As far as I know there are no logical substitutes for water's role in life.

More generally, life exists within a number of chemical limits which are basically impossible to get around. For example, if it's too hot, everything turns to gas and complex molecules break down - not good. If it's too cold, everything solidifes - not good. If the environment is too acidic or alkaline, complex molecules break down - not good. So scientists have good reasons for limiting the locations in which we'd expect to find life.

As far as life elsewhere in the Solar System is concerned, there are plenty of scientists who think there's a good possibility it exists. But they do so using the criteria for life on Earth, principally the existence of liquid water.

The Moon is considered an extremely unlikely candidate for life, but not just because of its almost complete lack of water. The lack of an atmosphere means chemicals either boil or freeze, leading to situations I mentioned above. On top that, solar radiation tends to break down complex molecules as well. So basically the environment on the Moon is about as life-unfriendly as it's possible to be.

WayneFrancis
2009-Mar-01, 12:44 PM
One thing that concerns me is that as soon as we start to visit non-earth locations we will start to take our bugs - viruses, bacteria etc and larger organisms with us. These bugs might survive to infect the local environment or they might die - who knows, and it seems like no-one cares either.


People do care. There is great care in taken when sending probes out. When we get a probe to Europa you can be assured that all steps will have been taken to make sure that the probe is completely sterile. We even pay attention to this here on earth. One of the biggest concerns about drilling into the huge lakes under the ice in the antarctic is the concern about contamination.



I realise that NASA probably try to make sure that things dont get into the spacecraft but this is unrealistic and we are bound to take some of our organisms with us when we go.


Yes it is possible.



Basically what I am saying is that we will be the equivalent of the Martians in War of the Worlds. We will be the invaders, we will be subject to and exposed to the bugs of all kinds that live on other planets. We have no immunity to these bugs and so it is likely that we will suffer strange diseases. We have spent thousands of years evolving with our native bugs and becoming immune to most of them, and as soon as we arrive on foreign planets we have to start all over again and so we are likely to become infected by them.


I suspect this is a natural safety system that prevents other beings from colonising our 'home' and us colonising other race's 'homes' too. In order to overcome this kind of protection system we would probably have to embark on a series of genetic engineering projects to mutate ourselves so that we are immune to their bugs.


actually this really is just science fiction. We are unlikely to find bugs like this. Lets look at things that have happened here on Earth then look at what would happen if those viruses and microorganism where taken to another planet.

Many people think of the War of the Worlds senario like what happens when white settlers brought diseases to the American Indian population. These diseases devistated the local populations.

Now look at the "why" it happened. Notice that those diseases only effected humans. They where things that evolved with humans and really only effected humans. The problem is that there was a human population that was not evolving with the diseases and building up an immunity.

If we took those diseases to Mars then most likely nothing would happen as far as "infecting" local life. Viruses that jump species are a special and fairly rare case. We worry about bird flue, and we should, but even with that it is a hard virus to catch right now if you are human and if you are, let say, a dog you don't even care about the bird flu.

So viruses are pretty much no threat to alien life. Viruses tend to target one or a few species and if the life isn't DNA base then viruses are completely harmless.

This leaves microorganisms like bacteria. Here is the bigger danger. If life else where is at a earlier stage then there is a good chance it will be food for the bacteria, if the bacteria can actually "eat" it. Otherwise the bacteria might just end up as food for the local life.

While some bacteria can survive very harsh conditions these bacteria normally do it in a dormant way awaiting better conditions to spring to life.



Do you think it is realistic to visit and try to colonise the Moon and Mars?

article about Building a Moon Base (http://www.universetoday.com/2008/02/07/building-a-base-on-the-moon-challenges-and-hazards/) although I have not got to the point where they discuss these things yet.

This last question isn't very related to the bigging of the post but I'm happy to put in my 2 cents worth.

No, but not for the reasons above. I'm not confusing colonising with exploration either.

The reason colonising isn't realistic in the near future is economic. There is no real reason to do it. It would be far cheaper and safer to learn how to build habitats at the bottom of the ocean then to build them on Mars and get migrants to live there.

Will it happen? Probably, when it become comercially viable and by that I mean that money can be made by not only corporations but the individuals actually doing the colonisation.

WayneFrancis
2009-Mar-01, 01:11 PM
...

Consider avian flu, CJD, and all the other viruses and bacteria that we have hidden away in our bioengineering labs such as ebola etc cowpox/smallpox etc

There are thousands of bacteria that live in inhospitable places such as deserts and deepsea fumes. This is one way that life may have started on earth, so to say that it is unlikely that they will mutate or be able to infect us is at best hopeful.

...


ummm but in that case what is the difference from humans and bacteria. If we colonise we will be changing and effecting possible local life as well. No one is saying that a virus or bacteria brought to Mars wouldn't mutate. Sure it would. In the case of Viruses the chance of it "infecting" alian life is about the same as if a metorite hits the earth blowing a chunk of earth into space and eventually hitting mars, the virus finding a suitable host and adapting. IE slim and none.



The trouble is with these things that once it is done, there is no going back - rather like the rabbit released into Australia or the various pests that find their way to foreign countries. They breed and colonise far more effectively than we can.

So why don't we all stay in our houses and never visit our neighbors. You going out tomorrow could give someone a virus that mutated in you and it could end up killing them.

The point is they do pay attention to this stuff these days and they take precautions against adverse effects.

ocpaul20
2009-Mar-01, 01:12 PM
Why is it "in your opinion" fairly stupid?Because there is no reason why life has to be based around water in other places, and to assume as much may make perfectly reasonable sense here on earth but on a different planet and in different environment, it may not be the case.

Our DNA determines what structures are made and how our bodies will maintain life. If the DNA is different for other beings, why shouldn't it for example make structures that allow breathing of methane and to extract the hydrogen from that to live on or make a body out of silica for instance. Just because we cannot conceive of something as weird as this does not make it impossible to exist. Thats all I am saying.

WayneFrancis
2009-Mar-01, 01:20 PM
There is no difference between Mars and the Moon and possibly other pieces of rock out there will have water and their own microbes too.

Currently NASA tell us that there IS water on both bodies and CO2 on Mars. This means that the possibility exists that microbes and spores that travelled on our spaceships or even on asteroids could set up camp there.

The point I am making is that 1) we have to be careful what we catch when we go there, and also 2) what we take there with us.

Maybe you honestly believe that space is as totally devoid of bugs as it is of aliens, but I think this subject is far more long-term life threatening in a hostile environment than the subject of what we build our moon/mars bases out of.

The article I linked to above did not even mention the contamination/microbe hazzard problem, but went on about how we should protect ourselves from meteors and what to make building from when there is no atmosphere.

The other point I would like to make is that USA may have steralised their spaceships but other countries have also sent spaceships out there and their priorities may be different and sterilisation techniques may not be as good.

I think you need to read up on some basic biology. Berkely have many university biology courses online.

WayneFrancis
2009-Mar-01, 01:30 PM
Not at all necessarily. I believe plenty of microbes come from meteorites, dont they? How do completely new strains of microbe suddenly appear?


Ummm completely new strains of microbes don't just suddenly appear. First a "strain" is a mutation of an existing micro organism. They do NOT appear from space. They may happen because of space, high energy cosmic rays messing up their genetic code a bit, but then again this is just one of many known ways genetic code can be altered. Meteorites are NOT involved.




Maybe they mutate, maybe they hitch a cosmic ride on a rock travelling from somewhere. Perhaps a different wavelength of solar radiation suddenly breaks them out of a long-dormant spore stage? We dont know all the possibilities and it is virtually impossible to trace a strain back to its origin.


Maybe invisible pink winged unicorns alter their genetics.

It si NOT virtually impossible to trace a strain back to its origins. These days it is pretty EASY to track strains back to their origins. There is a lot of money spent on this type of research.
http://evolution.berkeley.edu/evolibrary/news/060101_batsars

Please educate yourself in the relevant areas of biology before making statement like you are.

WayneFrancis
2009-Mar-01, 01:33 PM
...
If you're thinking that life from completely separate environments can interact in a meaningful way, say, like Klingon-Human half-breeds in Star Trek, then you're completely wrong.
...


Wait are you saying I can't marry a Klingon and have kids? Can I atleast have sex with a Klingon woman? :P

WayneFrancis
2009-Mar-01, 01:47 PM
How can I say that one country is more laid back about their cleanliness requirements? It is obvious isn't it?


Ummm no it isn't obvious...that is why we want some reference.



Please dont get hung up on this evidence thing and ask for it all the time. I am not going to name names just to give evidence. If you think what I say is not common sense then, of course, say so.


Are you listening to yourself? "Please don't get hung up on this evidence thing". Should we just trust your "Truthiness (http://en.wikipedia.org/wiki/Truthiness) should we?



We are assuming that life in the universe is based on water, but that may not be a fact. We are currently only looking for water-based life which in my opinion is fairly stupid, and is a fairly narrow-minded approach to alien/off-world life.


Ok...now you are getting into other "forms" of life. Do you realise that something that isn't based of of DNA and water would have no reason to fear most life on earth then it would to fear a piece of iron. If this life that is not based on DNA/Water then we are probably not going to have to worry about it any differently then we would have to worry about something like a methane atmosphere.



We have to begin to think outside the Earth-based science box and realise that if life has evolved around water here, it does not mean it has to evolve around water on a different planet - even in our own solar system.

No one says it has to. We expect it to because water is so abundant in the universe. Just like we expect most life in the universe to be carbon based because of the chemical properties of carbon. It is the chemical properties of carbon and water that work so well with life that makes us believe other "life" will probably be similar. Sure there might be other forms of life out there and some we might not be able to recognise. The most money gets spent on the areas that are deemed to be the most probably. There might be invisible pink winged unicorns in our own solar system too....I would question money being spent on that when there is little evidence of it and by the way there is more evidence of invisible pink winged unicorns then there is of non carbon based life that doesn't require water.

WayneFrancis
2009-Mar-01, 02:06 PM
Because there is no reason why life has to be based around water in other places, and to assume as much may make perfectly reasonable sense here on earth but on a different planet and in different environment, it may not be the case.


It isn't just because there is water hear on earth. It is the chemical properties of water that make it so likely. The same goes for carbon. It isn't because the earth has a lot of it. It is because of the chemical properties of carbon that make it the most likely basis of life.



Our DNA determines what structures are made and how our bodies will maintain life. If the DNA is different for other beings, why shouldn't it for example make structures that allow breathing of methane and to extract the hydrogen from that to live on or make a body out of silica for instance. Just because we cannot conceive of something as weird as this does not make it impossible to exist. Thats all I am saying.


Even if you have an organism that has coding proteins that can metabolise methane that DNA based life would still be expected to require H2O

Life based on Silicon has been thought of and 2 conclusions come from this.
1) That Silicon Life would probably have to come from a world where carbon is inaccessible to the processes that would form life.
2) That Silicon Life would be VERY slow. The chemical reactions with silicon is so much slower then that of carbon. What takes carbon based life to do in minutes could take days, month or years to do with silicon. Trust me if I'm being chased after by an alien life form I wouldn't mind it being Silicon based.

Liquid methane has been proposed as an alternative to water as a solvent. But because liquid methane needs to be so cold any life based off this would also be "slow" because all chemical processes would be slowed down. Give me a Silicon/methane alien trying to eat me over a lion any day.

Grashtel
2009-Mar-01, 11:53 PM
It isn't just because there is water hear on earth. It is the chemical properties of water that make it so likely. The same goes for carbon. It isn't because the earth has a lot of it. It is because of the chemical properties of carbon that make it the most likely basis of life.
OTOH hydrogen, oxygen and carbon being some of the most common elements in the universe certainly doesn't hurt the odds of extraterrestrial life being based on them.

WayneFrancis
2009-Mar-02, 12:26 AM
OTOH hydrogen, oxygen and carbon being some of the most common elements in the universe certainly doesn't hurt the odds of extraterrestrial life being based on them.

Agreed.

Man I didn't proof read that post did I....hear=here

Jens
2009-Mar-02, 04:25 AM
Not at all necessarily. I believe plenty of microbes come from meteorites, dont they?

If that is so, then our planet (along with Mars and the moon for that matter) is being bombarded with lots of microbes each day. Would you advocate building a shield to prevent that?

slang
2009-Mar-02, 09:57 AM
I believe plenty of microbes come from meteorites, dont they?

They don't. If you think otherwise: name one, with references please.

You may be mistaken with relatively complex molecules that can be considered precursors to life being found beyond Earth. But to compare that to microbes is like detecting iron in a supernova remnant and arguing that therefor there must have been cars in that system.

marsbug
2009-Mar-02, 11:23 AM
It's been proposed that we search the moon for meteorites from earth blasted off by ancient impacts. If we find them, and it seems likely we could, they might carry dormant terrestrial organisms that see humans as a tasty snack. The last impact big enough to have put meteorites on the moon was probably the dinosaur killer 65 million years ago. There are reports, unconfirmed, of microbes surviving in water inclusions in salt crystals for 250 million years (http://www.microbeworld.org/know/oldest.aspx). Terrestrial meteorites floating in space from a big impact might carry something to.

Given the resistance of some microbes to space conditions if shielded from UV there might be some nasty spores in orbit aboared various satellites we've launched. They might come nack to haunt our descendants one day.

These scenarios might be fairly unlikely but they are about the closest realistic scenario to the idea of 'alien' plauges wiping us out.

I think there is an outside chance earth might be reinfected by some microbial horror from it's own past but alien microbes aren't likely to doom us all. Of course I could be wrong........

JonClarke
2009-Mar-02, 11:55 PM
It's been proposed that we search the moon for meteorites from earth blasted off by ancient impacts. If we find them, and it seems likely we could, they might carry dormant terrestrial organisms that see humans as a tasty snack. The last impact big enough to have put meteorites on the moon was probably the dinosaur killer 65 million years ago. There are reports, unconfirmed, of microbes surviving in water inclusions in salt crystals for 250 million years (http://www.microbeworld.org/know/oldest.aspx). Terrestrial meteorites floating in space from a big impact might carry something to.

Given the resistance of some microbes to space conditions if shielded from UV there might be some nasty spores in orbit aboared various satellites we've launched. They might come nack to haunt our descendants one day.

These scenarios might be fairly unlikely but they are about the closest realistic scenario to the idea of 'alien' plauges wiping us out.

I think there is an outside chance earth might be reinfected by some microbial horror from it's own past but alien microbes aren't likely to doom us all. Of course I could be wrong........

Since we are constantly exposing ancient rocks through mining and oil extraction we are potentially releasing millions of spres and mkicrobes from the geological past into the modern environment. So far, no killer pugs have attacked us out of deep time.

Jon

slang
2009-Mar-03, 12:55 AM
So far, no killer pugs have attacked us out of deep time.

Jon, I have a LOT of respect for your knowledge and insights.. but .. killer pugs (http://en.wikipedia.org/wiki/Pug) out of deep time?

(I know you meant bugs. I know making fun of typos is bad form. I could not resist. Sue me. :) )

GOURDHEAD
2009-Mar-03, 03:27 AM
I know you meant bugs.Maybe not. The universe of pugs is larger than I thought. Minimizing ambiguity is usually worthwhile. Some definitions:

Pugs is a compiler and interpreter for the Perl 6 programming language, started on February 1 2005 by Audrey Tang.
en.wikipedia.org/wiki/Pugs

pug - small compact smooth-coated breed of Asiatic origin having a tightly curled tail and broad flat wrinkled muzzle
wordnet.princeton.edu/perl/webwn

The Pug is a toy dog breed with a wrinkly face and medium-small body. The breed is often summarized as multum in parvo ("much in little ...
en.wikipedia.org/wiki/Pug

Pug, also known as Milamber (after being taken by the Tsurani to their home world of Kelewan), is a fictional character appearing in the novels of ...
en.wikipedia.org/wiki/Pug_(fictional_character)

'Pug - Pup Parade was a comic strip in the UK comic The Beano. It centred around The Bash Street Kids' dogs, known as The Bash Street Pups, and their many adventures. It made its first appearance in issue 1326, dated 16 December 1967, and was drawn by Gordon Bell. ...
en.wikipedia.org/wiki/'Pug

pug - A small dog of an ancient breed originating in China, having a snub nose, wrinkled face, squarish body, short smooth hair, and curled tail
en.wiktionary.org/wiki/Pug

Also pug mill. A machine for consolidating plastic clay or body into a firm column. It consists of a barrel which tapers at one end to a die ...
www.smso.net/List_of_pottery_terms

pug - The Palladium Unified Government, the name of the Palladium's Hall Council.
www.nationmaster.com/encyclopedia/New-York-University%23E.-12th-Street-Residence-Hall

pug - This term is an acronym for Print (meaning "transfer") Under Glaze.
www.steincollectors.org/library/glossary.htm

pug - Nickname for mortar.
pgwake.tradesandcrafts.co.uk/diary/

JonClarke
2009-Mar-03, 06:25 AM
Jon, I have a LOT of respect for your knowledge and insights.. but .. killer pugs (http://en.wikipedia.org/wiki/Pug) out of deep time?

(I know you meant bugs. I know making fun of typos is bad form. I could not resist. Sue me. :) )

Doggone typos! :)

JonClarke
2009-Mar-03, 06:33 AM
Maybe not. The universe of pugs is larger than I thought. Minimizing ambiguity is usually worthwhile. Some definitions...

Also...

A pug is an abbreviation for pugilist

A "pug" is a what a pig is called in New Zealand

marsbug
2009-Mar-03, 08:36 AM
See Jon? Everyone agrees that you can't trust pugs, especially when they form spres which is one of the nastiest substances there is. Just because they've not made trouble yet doesn'tmean that they won't:) :P And I did say an outside chance!

WalrusLike
2009-Mar-03, 09:06 AM
I think OCPAUL has it wrong in dozen different ways. I present no evidence because I am feeling lazy.

I also believe that NASA does actually have a department, or at least a person, whose job it is to worry about this kind of thing.

One thing I have occasionally wondered about, is how sterile their probes are... I have heard that even after their best efforts there are still bacterial spores present on any piece of equipment. For future Europa sample missions (and others) this may be a significant concern. Anyone know if sterilisation is actually possible for this type of gear?

Jens
2009-Mar-03, 09:43 AM
Doggone typos! :)

I know. It's really rough. But I'd better bow out now.

JonClarke
2009-Mar-03, 09:45 PM
I know. It's really rough. But I'd better bow out now.

And no whining!

WayneFrancis
2009-Mar-03, 11:00 PM
Also...

A pug is an abbreviation for pugilist

A "pug" is a what a pig is called in New Zealand

and they all eat "fush en cheps"

cjameshuff
2009-Mar-04, 06:53 PM
ocpaul20: there really is nothing to worry about.

First, it's not short sighted or stupid to expect life to be water and carbon based...oxygen, hydrogen, and carbon are nearly impossible to avoid and have clear advantages for life. Water is an exceptional solvent, there really is nothing that is as flexible that is anywhere near as simple, stable, and common. Ammonia comes close, but is itself very unlikely to be found without water. Carbon is extremely flexible in the variety of compounds it can form, and almost certain to be accessible to any developing form of life...it is difficult to come up with a reason why it wouldn't be taken advantage of, even if the life somehow first arose using a silicon based biochemistry.

In any case, if there is some kind of weird mineral life on the moon, it's not going to find the human body a hospitable environment...it'd probably find itself dissolving or starving. To be a health risk, a microbe would first have to eat the stuff we're made of, and that requires being made of the stuff we're made of. It would also have to be able to thrive in the warm and wet environment of the human body, full of reactive and potentially toxic chemicals and quite possibly lacking in the nutrients it requires, it must be able to trick the immune system into overlooking it, and it must outcompete all the other microbes that have been evolving to to do these things for millions of years. That's for bacterial life...viruses would be worse off, because the greater part of their machinery of life is in their host. If an alien virus managed to inject its genetic material into a human cell, it would probably either kill the cell or just sit there, inert due to the lack of the right cellular machinery to create more of that virus.

Your scenario isn't even self consistent. You claim new microbes arrive at Earth all the time via meteors...so what new threat would we be exposing ourselves to on the moon or Mars? We've had strange new microbes falling on our heads for the entire history of our evolution, in your scenario. In reality, there is no evidence of previously unknown microbes arriving from space. New strains are new variations of already-known species, or old ones that have just recently been uncovered...there's a huge variety of microbial life on Earth.

WayneFrancis
2009-Mar-05, 12:08 AM
good post cjameshuff. I think it is mostly for the lurkers, which is fine, because I think ocpaul20 has left the building.

mugaliens
2009-Mar-06, 12:16 AM
Possible and feasible are two entirely different things. I believe both are possible, and entirely achievable given enough money, time, and effort. I also believe neither are economically feasible by a very wide margin.

solomarineris
2009-Mar-08, 09:10 PM
Do you think it is realistic to visit and try to colonise the Moon and Mars?

Realistic? Realistic?
Are you old enough to remember humans landed on Moon? Not only once but 4-5 times. We sent probes to Mars, they were able to survive harsh conditions year after year.
Unfortunately it was only America which had the technology then and now.
It just crazy to think we had all this know-how over 40yrs ago and gave up.
Reminds me the draft of Trailblazers, passing on Michael Jordan, as most of you know Bulls run away with half dozen championships.
The wars we fought, Carriers, UBoots, planes we built, if we had spent 20% of that money we'd be on Mars today, I have no doubt.
But it was only America then, the planet never caught up with us until recently.

WayneFrancis
2009-Mar-09, 11:56 AM
...
Unfortunately it was only America which had the technology then and now.
...


I'm not sure where you are getting your information from but there are other countries that have successfully sent probes. While Mars seems to be cursed for the Russians they have some limited successes there. The Russians have had great successes else where like Venus and the EU are doing pretty good as are the Japanese



[B]

It just crazy to think we had all this know-how over 40yrs ago and gave up.
Reminds me the draft of Trailblazers, passing on Michael Jordan, as most of you know Bulls run away with half dozen championships.
The wars we fought, Carriers, UBoots, planes we built, if we had spent 20% of that money we'd be on Mars today, I have no doubt.
But it was only America then, the planet never caught up with us until recently.

I beg to differ. Don't get me wrong. I'm a very patriotic American having served in the USMC from 88-94. But there are plenty of other successes out there. Russia is responsible not only for a lot of good science of other planets but if it was not for them we would be far less equiped to even think about long space flights by humans.