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Could this be the next big milestone in human space exploration?
Posted: 28 April 2012 10:44 AM   [ Ignore ]   [ # 31 ]
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FreeInKy - 25 April 2012 12:29 PM

Regarding waste disposal, would it take much energy to nudge it out of earth or moon orbit towards the sun? And once started on that trajectory, would it necessarily fall into the sun? Because that’s one hell of a natural incinerator!

The Earth is doing about 1000 miles per minute to orbit the Sun at this distance.  So you would have to eliminate a lot of velocity to make a mass on the Earth fall into the Sun.  Why not drop it on the far side of the Moon?  We would not even have to see it.  LOL

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[ Edited: 29 April 2012 07:36 AM by psikeyhackr ]
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Posted: 28 April 2012 12:15 PM   [ Ignore ]   [ # 32 ]
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Quest of Knowledge - 28 April 2012 10:02 AM

Ever since I learned about the existence of water in comets and asteroids some time ago, I have asked myself the question if this could be the way life travels in the universe.  It appears that life on Earth started in water and that it evolved from simple organisms to complex ones.

Well ... but life evolved crucially in liquid water, which doesn’t exist on meteorites. Meteoritic water is a solid or a sublimated gas.

Of course, if the meteoritic water were (hypothetically) blasted from a planet with liquid water containing life, and if that life froze in the ice and (hypothetically) remained viable for billions of years ...

Quest of Knowledge - 28 April 2012 10:02 AM

When meteorites enter the Earth, they enter through the atmosphere which burns a large percentage, or all of it, and probably most living organisms if they existed.  That process would be bypassed if portions of the meteorites where brought to Earth encapsulated.

There’s no reason, though, to believe that meteoritic ice would all be burned off on entry. Given the enormous tonnage of meteorites that have fallen on Earth in the past billion years, if that water contained viable organisms, they would already be here, from meteoritic meltwater.

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Posted: 28 April 2012 07:38 PM   [ Ignore ]   [ # 33 ]
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dougsmith - 28 April 2012 12:15 PM
Quest of Knowledge - 28 April 2012 10:02 AM

Ever since I learned about the existence of water in comets and asteroids some time ago, I have asked myself the question if this could be the way life travels in the universe.  It appears that life on Earth started in water and that it evolved from simple organisms to complex ones.

Well ... but life evolved crucially in liquid water, which doesn’t exist on meteorites. Meteoritic water is a solid or a sublimated gas.

There is life in ice at least -60Celsious, maybe colder. You might like to check these links: discovermagazine.com/2008/feb/did-life-evolve-in-ice http://www.dailymail.co.uk/sciencetech/article-1249632/Saturns-icy-moon-Enceladus-contain-life.html  http://www.actionbioscience.org/newfrontiers/deming.html 

Of course, if the meteoritic water were (hypothetically) blasted from a planet with liquid water containing life, and if that life froze in the ice and (hypothetically) remained viable for billions of years ...

Quest of Knowledge - 28 April 2012 10:02 AM

When meteorites enter the Earth, they enter through the atmosphere which burns a large percentage, or all of it, and probably most living organisms if they existed.  That process would be bypassed if portions of the meteorites where brought to Earth encapsulated.

There’s no reason, though, to believe that meteoritic ice would all be burned off on entry. Given the enormous tonnage of meteorites that have fallen on Earth in the past billion years, if that water contained viable organisms, they would already be here, from meteoritic meltwater.

It is possible that if meteorites carry dormant life in its ice that some micro organisms may have survived the landing, but that would imply that those dormant living organisms could withstand thousands of degrees of heat as the meteorites that enter the earth ignite when they cross the atmosphere.

[ Edited: 28 April 2012 08:19 PM by Quest of Knowledge ]
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Posted: 29 April 2012 05:17 AM   [ Ignore ]   [ # 34 ]
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Quest of Knowledge - 28 April 2012 07:38 PM

There is life in ice at least -60Celsious, maybe colder. You might like to check these links: discovermagazine.com/2008/feb/did-life-evolve-in-ice http://www.dailymail.co.uk/sciencetech/article-1249632/Saturns-icy-moon-Enceladus-contain-life.html  http://www.actionbioscience.org/newfrontiers/deming.html 

Those links do not show that life exists (much less evolved) in solid ice. E.g., this quote from the last link: “However, I am interested in what happens in the coldest ice that still has enough liquid water in it to support active microbial life forms and so I go to the Arctic in the winter.”

All life forms we know require liquid water. Those microbes that exist in sub-freezing temperatures do because they have managed to evolve methods of antifreeze, for one thing, to keep ice crystals from piercing cellular membranes.

Quest of Knowledge - 28 April 2012 07:38 PM

It is possible that if meteorites carry dormant life in its ice that some micro organisms may have survived the landing, but that would imply that those dormant living organisms could withstand thousands of degrees of heat as the meteorites that enter the earth ignite when they cross the atmosphere.

The outer surface of meteorites will burn off on atmospheric entry, but what remains of the core can still be well below freezing when it impacts earth. E.g., see HERE:

Although the fusion crust may be warm or hot immediately after impact, the inside of the meteorite is still deep frozen from eons in cold space.

I can’t find the citation just now but I recall hearing that people who find meteorites that have just landed will often find them covered in a thin layer of frost.

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Posted: 29 April 2012 05:46 AM   [ Ignore ]   [ # 35 ]
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Quest of Knowledge - 28 April 2012 10:02 AM

If asteroids contain life, it could be the type of life that could take hold in even adverse conditions, like seeds do.  That life could be in the form of viruses and bacteria with aggressive DNAs.  This is pure speculation, yet a real possibility and that is why extensive exploration of asteroids should be conducted before bringing any preserved material to Earth.

When meteorites enter the Earth, they enter through the atmosphere which burns a large percentage, or all of it, and probably most living organisms if they existed.  That process would be bypassed if portions of the meteorites where brought to Earth encapsulated.

This makes a nice cheezy scifi movie but not really very good science. First of all most meteorites are iron or stoney. The small proportion that are carbonaceous chondrites which have organic molecules in them have fallen to earth and no evidence of life has ever been found in any of them. Its naive to think that if life formed it would form on the surface and would have been burned off during the fiery entry through the atmosphere. Carbonaceous chondrites are porous and space is a very hostile place. Not just because of the cold and the vacuum and the dearth of liquid water but also because of the dangerous amounts of radiation. For any organism to survive it would have to exist in the interior of these meteorites and we should have seen some evidence on examination.

Think about the argument you are making here. You are suggesting panspermia asa the source of life on earth which means that life would have had to survive this fiery fall to earth but then you are saying that meteorites that fall to earth today wouldn’t carry such evidence because it would have been burned off. We can’t have it both ways. Either life survives this process or it doesn’t.

While there might be some remote chance that life could exist in some primitive form in these asteroids ( It would have to be really remote because all our examinations of martian and lunar samples have shown nothing) I think it is a bit silly to worry about bringing it back to earth since these things are falling to earth every single day and in the past they fell to earth in massive numbers.. both asteroid and cometary debris. Whatever is out there.. if there is anything.. most likely has already fallen to earth in the past and will again in the future, and there is not much we can do about that. With over a ton of this stuff landing on earth every day I don;t think there is much we need to worry about when it comes to a small amount being brought back by an asteroid mining company.

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Posted: 29 April 2012 06:07 AM   [ Ignore ]   [ # 36 ]
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I agree with your conclusions, macgyver, but I assume he’s talking about comets (high in water ice) rather than carbonaceous chondrites. And FWIW there have been some organisms that have managed to survive for short periods in space; e.g. tardigrades. Of course, the fact that they survived a few days doesn’t go very far towards showing that something could survive a billion years or so, but OTOH they are also very complex organisms compared to, say, a bacterium, virus or snippet of DNA ...

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Posted: 29 April 2012 06:29 AM   [ Ignore ]   [ # 37 ]
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My question is why life would have to have originated somewhere else.  Our solar system and earth’s composition lend itself perfectly for the generation of real life. While perhaps some compund elements crashed as part of meteors, etc., is there any evidence that earth’s living organisms should not have originated on earth.
Seems to me early earth offered a perfect pertrie dish for nature to experiment and come up with something. That’s all it takes, something that an duplicate itself and use its environment to procreate.

I am sure there are other planets with life forms in the universe, each developing independently. We can see here on earth that life can exist in extreme temperatures, i.e. -60 ice and +600 sulphur vents in the ocean. IMO, give it some stuff, the right conditions, and time, nature will produce something.

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Posted: 29 April 2012 06:37 AM   [ Ignore ]   [ # 38 ]
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You are probably right but this whole discussion was about mining asteroids. The people proposing this project are not talking about mining comets. Their orbits are too elliptical to make mining practical. Even so thousands of comets have hit earth in its history, most recently 100 years ago in Tunguska. On a geologic time scale they have been raining down on us so I’m not sure there is much reason to be concerned about bringing home some cometary material even if that were the plan and its not.

I am aware of the ability of tardigrades ( very interesting critters by the way for anyone with a microscope and some wet moss in the yard and an interest in taking a look at them) to survive exposure to space for days but as you say that is a far cry form being out there for billions of years especially during things like solar flares. Surviving in space once an organism has evolved on earth and evolved mechanisms to protect against and repair radiation induced DNA damage is a lot different from postulating that life could begin and evolve under those conditions. Amino acids and DNA are delicate molecules. Its difficult to say that this would be impossible in space since we don’t know how life begins in the first place but it seems like it would be difficult unless it was protected in the interior of the asteroid/comet.

At any rate Quest cant have it both ways. You cant postulate that life came here on a comet and then say that current day comets/meteorites are sterilized by the heat of entry through the atmosphere.

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Posted: 29 April 2012 06:44 AM   [ Ignore ]   [ # 39 ]
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Agreed, macgyver. There’s no way that life as we know it could have evolved in solid water ice. No way. Though it could have been preserved in stasis (or its DNA could have been), if so, it would have saturated earth long ago.

Fred Hoyle wrote an SF novel about the possibility of life evolving in large dust clouds around stars. The clouds themselves became sentient. I have no idea if that would be possible or ever would have happened, but if so, it’d be a very different sort of life than the stuff down here on earth. (All I’m saying is that it’s theoretically possible for a very different sort of life to have evolved in space).

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Posted: 29 April 2012 07:39 AM   [ Ignore ]   [ # 40 ]
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Write4U - 29 April 2012 06:29 AM

My question is why life would have to have originated somewhere else.

Exactly!  That is nothing but pseudo-intellectual speculation.  Until there is significant evidence to suggest it why waste time discussing it.

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Posted: 29 April 2012 10:12 AM   [ Ignore ]   [ # 41 ]
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dougsmith - 29 April 2012 05:17 AM

Those links do not show that life exists (much less evolved) in solid ice. E.g., this quote from the last link: “However, I am interested in what happens in the coldest ice that still has enough liquid water in it to support active microbial life forms and so I go to the Arctic in the winter.”

All life forms we know require liquid water. Those microbes that exist in sub-freezing temperatures do because they have managed to evolve methods of antifreeze, for one thing, to keep ice crystals from piercing cellular membranes.

I am speaking of a hypothetical dormant “seed of life” that would not be even as developed as a single cell.  I am not saying that life would evolve in the meteorite, but rather that the essential components to restart life elsewhere could be present in some meteorites and comets.

Obviously, I cannot provide any citations because there is no proof that they exist, as there was no proof in Europe that the Americas existed before Europeans saw it for the first time.

It does not make sense to me that life would exist on Earth only.  Perhaps life could begin in any planet under the right circumstances, but I postulate that it might be more likely that the “seed of life” travels through the universe and that it starts when it lands within the right circumstances.

The outer surface of meteorites will burn off on atmospheric entry, but what remains of the core can still be well below freezing when it impacts earth. E.g., see HERE:

Although the fusion crust may be warm or hot immediately after impact, the inside of the meteorite is still deep frozen from eons in cold space.

I can’t find the citation just now but I recall hearing that people who find meteorites that have just landed will often find them covered in a thin layer of frost.

I agree with that.  When those meteorites land, much of the hypothetical life might be destroyed all the same and what if there some life components left they would be mostly spread in small amounts and mostly in isolated areas or the oceans.

Bringing large amounts of intact meteorites would potentially pose a health risk to urban centers if they were to contain life and the material was brought into contact quickly within the general population.

This is all speculation, obviously, and it hinges on the possibility of meteorites containing some sort of life or “life starter” within. If there is no life of any sort in or on the meteorite, then there is nothing to worry about.  If there is some sort of life form or “life starting” components, then more of a reason to explore meteorites with the hope of better understanding how life evolved on Earth, albeit with extreme caution do to potential harm to life on Earth.

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Posted: 29 April 2012 10:29 AM   [ Ignore ]   [ # 42 ]
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Quest of Knowledge - 29 April 2012 10:12 AM

I am speaking of a hypothetical dormant “seed of life” that would not be even as developed as a single cell.

Explain. Do you mean a snippet of DNA molecule? An entire genome?

“Seed of life” as such is meaningless.

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Posted: 29 April 2012 11:21 AM   [ Ignore ]   [ # 43 ]
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dougsmith - 29 April 2012 10:29 AM
Quest of Knowledge - 29 April 2012 10:12 AM

I am speaking of a hypothetical dormant “seed of life” that would not be even as developed as a single cell.

Explain. Do you mean a snippet of DNA molecule? An entire genome?

“Seed of life” as such is meaningless.

It could be DNA or something that could produce DNA.  “Seed of life” is indeed a meaningless name.  It is just a way of calling a hypothetical something that could result in the start of life organisms.  I don’t even want to speculate as to what form that would have because there is no information to base it on.

Some viruses, such as the HIV virus, the Hep C virus, are extremely fragile and they last very little time without a host.  The people who had the right conditions for those viruses to survive and to take over their bodies would not think of those viruses as fragile.

That is my concern and why I think that thorough investigation of potential harm to Earth should be conducted before bringing anything back to Earth.

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Posted: 29 April 2012 11:35 AM   [ Ignore ]   [ # 44 ]
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I agree with doug. That term has no meaning at all. You are postulating that life begins from unknown seed but you dont seem to have any idea what you mean by that.

I agree that we know little about the actual origin of life and there are many possibilities but you are proposing that there is some sort of pre-cellular unit of life that might be potentially dangerous. I doubt such a thing exists but if it did and there was a remote chance that such a primitive form of life could survive and cause harm, all the other arguments I made still stand. There is no reason to suspect that such primitive “seeds” as you call them would only exist on the surface of the meteorite. In fact it makes much more sense that they would be in the interior. As I said before you are proposing that these “seeds” survived the heat of entry to plant life here in the first place, but then you suggest that current meteorite samples are somehow sterilized and the seeds don’t survive. You aren’t being consistent. If we’re going to worry about what gets brought home by miners we need to be concerned about ton of material that falls to earth every day and that doesnt seem to have caused any trouble so far.

I have to say I dont agree with you basic premise. I agree that life probably exists throughout the universe in many places and panspermia may even occur in rare circumstances under the right conditions but there is absolutely no reason to invoke this as an explanation for life on earth or any other place it has sprouted up. First we have no evidence for it and secondly it does nothing to help us explain the origin of life. It simply displaces the origin to another location. You still have to explain how it originated there and why should some place other than earth be an easier place for life to originate?  I think it makes far more sense and is a simpler theory to propose that under the right conditions life will emerge without needing to be seeded from somewhere else. Unless there is good evidence to the contrary Occams razor would seem to suggest panspermia is not the most probable explanation for the origin of life on our planet.

[ Edited: 29 April 2012 11:42 AM by macgyver ]
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Posted: 29 April 2012 02:11 PM   [ Ignore ]   [ # 45 ]
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Quest,
I am speaking of a hypothetical dormant “seed of life” that would not be even as developed as a single cell.  I am not saying that life would evolve in the meteorite, but rather that the essential components to restart life elsewhere could be present in some meteorites and comets.

That is precisely why life on earth would have started on earth and life elsewhere would develop there. The “essential components” to “start” life are found throughout the universe, in abundance.

IMO, I should think that a reasonably hospitable environment anywhere would inevitably produce some form of life. The universe is a giant chemical laboratory. All essential elements are present everywhere.  If we can duplicate the building blocks of life in a petrie dish in a few years by simulating a favorable condition, is it not entirely logical to conclude that 14 billion years of experimentation on billions of planets would produce something resembling life?

The “seed (secret) of life” is naturally contained in the mathematical nature of chemistry and the inherent potential of elements to combine in certain predictable ways under similar conditions and in other predictable way under different conditions. IMO, life was an “inevitable” result of the way things work at a most fundamental level.

But the question if mining might introduce something virulent into our system, is a valid question.  If life can and does develop throughout the universe, importing stuff from other planets (with a reasonably hospitable environment) which is rich in the stuff we need, there is a possibility that something which interacts with our own stuff might well be present. It would not necessary have to be “alive”.  We have a habit of introducing carcinogens and other deadly compounds into our everyday lives from stuff we mine or create on earth. Mining off planet should present the same threats as mining here.

A perfect example is our experience with aerosols (chlorine) interacting with (depleting) our ozone layer. If we had not discovered this “deadly” interaction, our lives on earth might already have been drastically altered.

[ Edited: 29 April 2012 02:17 PM by Write4U ]
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