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soop
2002-Jul-01, 12:03 AM
You have 100 bucks. How much would you bet on:
A. Europa has a liquid ocean
B. Europa currently harbors life

If life existed on Europa, it would obviously need energy.
A convientient way to get it would be to tap hot springs on earth, much like the famed tube worms on Earth.
Another possibility is simply to exploit the temperature differnce between the colder waters near the surface of the ocean (if it exists!) and the warm waters below. Granted, the organism would have to be rather large (miles) in lenghth, but if you look at the towering columns of kelp that exist on earth, it seems possible.
Sunlight, while avalible in the depths of the ocean, is sometime avalible near the surface. A life form might take advantage of that oppurtunity.
Life could even exist in the ice of Europa, with the help of natural antifreeze.
Finally, through some clever adaptions, it is possible life could take advantage of the electrical field assoisated with Jupiter (although the mechanisms behind this I can't imagine...anyone here with enough biology to shed some light?).

The European ocean probarly does not contain too much oxygen. This may or may not be a problem (to my knowledge tube worms are not Oxygen dependant but I'm not sure about this).
Besides, it's concievable that sulfur could do a lot of oxygen's jobs (although not nessisarly with equal efficency).

Ok. This post is already too long. How about some opinions and answers? And bets!

Rift
2002-Jul-01, 12:08 AM
I have another one...

C- Hoagland would take credit and claim he discovered it first, no matter what the outcome. /phpBB/images/smiles/icon_razz.gif

Peter B
2002-Jul-01, 12:48 AM
Hmmm. Just to avoid confusion, I think a better adjective of Europa would be "Europan".

There's definitely life in Europe! /phpBB/images/smiles/icon_wink.gif

Silas
2002-Jul-01, 01:09 AM
Sorry to be a nay-sayer (or merely an advocate of the null hypothesis) but I'd bet the full amount against there being native life on Europa.

(And I want my money back if we contaminate the satellite with earth-based bacteria!)

Silas

nebularain
2002-Jul-01, 03:42 AM
I agree with Silas. Water, although essential for life as we know it, is only one of the essentials necessary. As far as I've heard, there has not been any indications of the other essentials.

Water + ??? = Water and ...well?...

xriso
2002-Jul-01, 08:48 AM
On 2002-06-30 20:03, soop wrote:
You have 100 bucks. How much would you bet on:
A. Europa has a liquid ocean
B. Europa currently harbors life

If life existed on Europa, it would obviously need energy.
A convientient way to get it would be to tap hot springs on earth, much like the famed tube worms on Earth.
Another possibility is simply to exploit the temperature differnce between the colder waters near the surface of the ocean (if it exists!) and the warm waters below. Granted, the organism would have to be rather large (miles) in lenghth, but if you look at the towering columns of kelp that exist on earth, it seems possible.
Sunlight, while avalible in the depths of the ocean, is sometime avalible near the surface. A life form might take advantage of that oppurtunity.
Life could even exist in the ice of Europa, with the help of natural antifreeze.
Finally, through some clever adaptions, it is possible life could take advantage of the electrical field assoisated with Jupiter (although the mechanisms behind this I can't imagine...anyone here with enough biology to shed some light?).



As far as I know, Europa is thought to have a rather thick layer of ice. Something like 6 km thick minimum (others have suggested a minimum 20 km!). Apparently there is something like 100 km of water (solid or liquid) above the rocky core of the planet. I haven't done any calculations on the energy Europa gets, but I'd figure that it could have at least *some* liquid water above the rock, just from tidal forces exerted by Jupiter. I'd probably bet some non-zero amount.

As for life, who knows. The odds of one planet successfully transferring life to another seems to be pretty darn low. Could life have originated there on its own? Can life even survive there at all? Myself, I'd wait to see what the composition of the planet is.

Azpod
2002-Jul-01, 07:01 PM
I'd bet it all on Europa having an ocean. Even if it doesn't have life, it's pretty likely that it at least has an ocean!

Seriously, I think it is likely that Europa has life. Without an energy source, no liquid water could exist on Europa. It has been shown time and again that tidal friction alone could provide the energy needed for at least a small ocean. While such an ocean has not been directly observed, there is evidence suggesting its existance.

If life can and does arise rather easily (as I understand that the current thinking is that it does), then there should be no reason why life couldn't have started on Europa, perhaps when it was still a young, warm world without the ice crust that it has today. Such life could survive to this day, trapped near hot springs at the bottom of a vast liquid water mantle. Perhaps life even could arise on its own near such springs.

If we go and find that Europa has an ocean and energy but is completely sterile, then we would have to rethink how easily life may arise, and how common even simple life may be in the universe as a whole. If, however, we go and find life on Mars, Europa and Callisto, then it could mean that our nearest intelligent neighbor may be closer than we thought.

Wiley
2002-Jul-01, 07:06 PM
On 2002-06-30 20:48, Peter B wrote:
Hmmm. Just to avoid confusion, I think a better adjective of Europa would be "Europan".

I prefer "Europaian". Although "Europian" would be fine if you place the accent second syllable.



There's definitely life in Europe! /phpBB/images/smiles/icon_wink.gif

Yes, but intelligent life? /phpBB/images/smiles/icon_smile.gif

xriso
2002-Jul-01, 08:14 PM
On 2002-07-01 15:01, Azpod wrote:
I'd bet it all on Europa having an ocean. Even if it doesn't have life, it's pretty likely that it at least has an ocean!


I'd probably do that too, if I were a betting kind of guy.



If life can and does arise rather easily (as I understand that the current thinking is that it does) ...



I guess it depends whose current thinking it is. Last I heard, scientists have been having a hard time figuring out how life on Earth started. Perhaps the upcoming ISSOL conference will shed more light on this matter.

A number of mathematicians have also commented on just how improbable it is to get that first bit of life.

beskeptical
2002-Jul-02, 03:01 AM
I'm betting on 'Europan' life and the ocean. ('Europaian' just doesn't have the right phonetics and I was going to comment on 'European' if Peter B. had not already done so.)

I think the topography is pretty strong evidence for liquid underneath though I understand the tidal forces may just be creating surface liquid.

As for life, my current stand is life is common. I think evolution of life is inevitable in a broad range of conditions given enough time.

I hope some of us are still in touch when the probes get there so at least some of us can gloat, (and, that doesn't have to be me, then again... /phpBB/images/smiles/icon_wink.gif ).

beskeptical
2002-Jul-02, 03:17 AM
On 2002-07-01 16:14, xriso wrote:
I guess it depends whose current thinking it is. Last I heard, scientists have been having a hard time figuring out how life on Earth started. Perhaps the upcoming ISSOL conference will shed more light on this matter.

A number of mathematicians have also commented on just how improbable it is to get that first bit of life.


Not to get this thread started again (see back under 'rare earth'), but biologists in the genetics field are not having a hard time figuring out how the first life forms arose. Gerald Joyce and colleagues at the Scripps Institute have the basics down and are at the experimental stage creating the first active organic molecules from non-organic ones.

And the mathematicians have to have the right formula if they are going to have accurate predictions. Are you speaking of the formula from Sagan using number of Earthlike planets etc., or a calculation of how many chemical combinations are possible in the original 'soup' and how many of those combinations would result in life?

Geneticists have the details of what it takes to go from inorganic to replicating organic molecules and while it might take a billion years for the first life forms to begin, well probability is relative. Given the time scale and size of the Universe, we're here aren't we?

xriso
2002-Jul-02, 06:28 AM
On 2002-07-01 23:17, beskeptical wrote:

Not to get this thread started again (see back under 'rare earth'), but biologists in the genetics field are not having a hard time figuring out how the first life forms arose. Gerald Joyce and colleagues at the Scripps Institute have the basics down and are at the experimental stage creating the first active organic molecules from non-organic ones.


I could write more about this but neither of us want to open that can of worms (relevant it may be).

Back to Europa, do you think that it even has the prerequisites for life?

David Hall
2002-Jul-02, 06:42 AM
I would gamble all but a few bucks on the existance of oceans. I'd put a small amount on the longshot of there being life, but I wouldn't count on it. My personal feeling is that life is a fairly rare phenomenon that needs relatively benign conditions to get started.

If we were talking about Mars, I'd bet almost the same way; that there is underground water, but not much chance of life. But I'd give it a higher probablity that there was life on the planet in the past.

soop
2002-Jul-02, 02:18 PM
What are the prerequisites for life, as far as we know them?

Well, here are some:

>Water
>Organic compounds
>Source of energy

Europa seems to have all three.
There are a few problems, one of them being lack of oxygen. Although sulfur could carry it's place, I'm not convinced that anything would be more efficent than oxygen respiration. This might put a damper on large multicellular life.

Or it might not. Evolution has habit of suprising us.

beskeptical
2002-Jul-02, 08:35 PM
On 2002-07-02 10:18, soop wrote:
What are the prerequisites for life, as far as we know them?

Well, here are some:

>Water
>Organic compounds
>Source of energy

Europa seems to have all three.
There are a few problems, one of them being lack of oxygen. Although sulfur could carry it's place, I'm not convinced that anything would be more efficent than oxygen respiration.

Didn't the primordial Earth have a predominately CO2 atmosphere until various evolutionary life cycles reversed the composition by locking up the CO2 in limestone deposits? Or something like that.

Also, doesn't water have free oxygen? Earth's oceans certainly do.

Life around our ocean's volcanic vents exists in the same conditions that could be present on Europa. If there is a liquid ocean on Europa, the implication is that volcanic activity would be the likely source of heat.

Azpod
2002-Jul-02, 11:18 PM
There are a few problems, one of them being lack of oxygen. Although sulfur could carry it's place, I'm not convinced that anything would be more efficent than oxygen respiration. This might put a damper on large multicellular life.

Or it might not. Evolution has habit of suprising us.


That's why I would bet on Europan life existing, but I would bet against there being any large multicellular organisms.

Here's hoping that I'm wrong, tho! /phpBB/images/smiles/icon_biggrin.gif It'd be interesting to see what type of aquatic creatures would be native to Europa if the did exist!

DaveC
2002-Jul-03, 05:15 PM
We know from our observations here on Earth that life is incredibly resilient and adaptable. The answer to the question of whether life exists on Europa (or Mars, or any other extraterresrial body) is really tied to the question "Did the conditions ever exist there for a long enough period for life to initially arise?" If we think the answer is yes, then the odds are probably quite good that life still exists. Not necessarily very complex life, but that wasn't the essence of soop's original challenge.

So David Hall's comment:
"If we were talking about Mars, I'd bet almost the same way; that there is underground water, but not much chance of life. But I'd give it a higher probablity that there was life on the planet in the past" doesn't fit with my view. If Mars had life at some point, the only way I could see it all becoming extinct is if there was a very drastic and very short-term change in the environment to something radically different than any pre-extinction condition.
That's possible, but highly unlikely. Life on earth occupies virtually every existing environmental niche. Some of it would survive almost any environmental change you could imagine.

So, I'd bet Europa has oceans, and since it appears to also have the prerequisites for life as we know it, Id even put a few bucks (Canadian, though) on there being some form of simple life there. My position assumes a couple of things that I have no idea about: that Europa is not a recent arrival from deep space (a captured comet or something) but rather it evolved as a Jovian satellite for a long time: and, there is indeed a source of carbon and nitrogen within the Europan environment.

traztx
2002-Jul-03, 06:29 PM
On 2002-06-30 20:03, soop wrote:
You have 100 bucks. How much would you bet on:
A. Europa has a liquid ocean
B. Europa currently harbors life


A. 60
B. 0

I love this photo:
http://antwrp.gsfc.nasa.gov/apod/image/9803/europaclose_gal_big.jpg

David Hall
2002-Jul-03, 06:43 PM
On 2002-07-03 13:15, DaveC wrote:
So David Hall's comment:
"If we were talking about Mars, I'd bet almost the same way; that there is underground water, but not much chance of life. But I'd give it a higher probablity that there was life on the planet in the past" doesn't fit with my view. If Mars had life at some point, the only way I could see it all becoming extinct is if there was a very drastic and very short-term change in the environment to something radically different than any pre-extinction condition.


Ok, I'll grant that. If Mars managed to bring forth life in the past, then I'd also agree that there may be simple life forms still living in selected regions. Those regions having sufficient access to water and a usable energy source. But in it's present state it doesn't look too hospitible, so I wouldn't discount it being sterile either.

Now as for life actually arising, I'd put much greater odds of it happening on Mars than on Europa. We know the conditions on Mars were much more favorable in the past, but as far as I know, Europa has always been an ice-ball.

David Hall
2002-Jul-03, 06:46 PM
On 2002-07-03 14:29, traztx wrote:

A. 60
B. 0


So what are you going to do with the other forty? Make some other side-bet? (We find some of Hoagland's glass towers there for example) /phpBB/images/smiles/icon_biggrin.gif

DaveC
2002-Jul-03, 07:03 PM
On 2002-07-03 14:43, David Hall wrote:
Now as for life actually arising, I'd put much greater odds of it happening on Mars than on Europa. We know the conditions on Mars were much more favorable in the past, but as far as I know, Europa has always been an ice-ball.


I agree with you. Nothing we know seems to suggest that Europa has ever had anything other than a very extreme set of environmental conditions. Mars, on the other hand appears to have been somewhat Earthlike at some point in the past.

The environs of deep sea vents here on Earth harbour some unusual life forms - and those enviromnmental conditions may well be duplicated on Europa BUT the fact that life has adapted to a thermal vent environment isn't the same as saying it arose in that environment. Thermal vents may bear no resemblance at all to the environment necessary for life to arise - and in fact probably don't.

So the existence of a "life friendly" environment can't be necesarily used to conclude that life exists there. What is needed is a biogenesis-friendly environment at some point in the distant past. Europa may never have had that. Mars almost certainly did. The only issue is whether it had such an environment long enough for life to arise and prosper.

Paul Unwin
2002-Jul-03, 07:28 PM
I'd bet against life on or in Europa. That way, I'm a winner no matter what.

Then again, how would I ever prove there is no life to win my bet?

Paul "attempt no landing there" Unwin

DaveC
2002-Jul-03, 07:40 PM
Good point, Paul. Those that bet against life existing will have some difficulty with those who bet for life. Failing to find it doesn't mean it's not there. On the other hand, finding it is absolutely conclusive.
So, in fact, if you bet there is no life on or in Europa (as opposed to Europe!) you can't win the bet.

Paul Unwin
2002-Jul-03, 10:12 PM
Now, this slight imbalance is easily fixed if we change the bet slightly. Instead of betting whether Europa currently harbors (or ever harbored) life, we should ask whether humans will ever find proof of that life. Even still, the question would be open to some confusion, as not everyone will agree that a given piece of evidence constitutes proof. There will, after all, be those who believe any mission to Europa is a hoax.

Paul "Someday, the children of the new sun will meet the children of the old" Unwin

soop
2002-Jul-03, 10:49 PM
>What is needed is a biogenesis-friendly environment<

So here is the real crux of the matter. And it's very difficult since we don't know exactly how biogenesis occurs.
Let's run through what we think were the conditions on earth:

1. So called primordial soop:-) of simple elements and compounds: Water, some carbon, sulfur, methane, ammonia, etc (all the stuff they had in those Stanley Miller type experiments).
2. Energy (UV rays AND OR Lightning)

With these two conditions in place, life arose on Earth.

So, are these two conditions avalible on Europa?

Energy is certianly there: electrical currents exist between Europa and Jupiter (and forms of radiation as well).

It is likley that the needed elements are their (I see no reason why methane, ammonia, etc would be absent from the moon).

Of course, how it happened on Earth might not be the only way it could happen.

The presence or non presense of multicellular life is also up to much debate. I think that if there happens to be UNICELLULAR life on Europa then there is very likely to be larger multicellular organism. It is fasinating to imagine what forms life could take on an enviorment such as Europa...

Chip
2002-Jul-04, 12:40 AM
On 2002-07-03 18:12, Paul Unwin wrote:
"...we should ask whether humans will ever find proof of that life. Even still, the question would be open to some confusion, as not everyone will agree that a given piece of evidence constitutes proof. There will, after all, be those who believe any mission to Europa is a hoax."
You bring up an interesting point in light of the still on-going controversy over possible fossilized evidence of life within the famous Martian meteorite. For example: If there is life in Europa, it might be chemically discernible by our understanding of Earth's biology, yet outwardly so bizarre as to appear to stand squarely in the middle between living and non-living matter.

By way of analogy, here is a hypothetical example: Suppose the HST discovered an extremely vast, orderly structure in deep space. The structure appeared to be made from natural material (such as interstellar dust) that had been apparently corralled into some kind of intelligent symmetry. (Like hiking across rough country and suddenly coming upon an 18th century English garden!) (Or collecting snowflakes, and suddenly realizing their symmetrical design.) Further, suppose the structure was also the source of much deep space noise and radio activity which had long been understood as the result of star formation, but was now discovered to have a coherent relationship if seen as a whole.

A debate would follow between those who cautioned that such a huge shape, (light-years across in order to be detected by Hubble,) could be a newly discovered natural phenomenon, perhaps a special case that is the result of multiple pulsars whose flashing frequencies and ejecta combined to form a symmetrical nebula; and those who point to that very artificial symmetry as evidence of a vast alien construction (alla Lowell's Martian canals). Anyway, if life were discovered on Europa, I think a similar controversy within the scientific community would arise. Further data and testable theories would develop from there.

(If this fictional example were really discovered, it would be seen by independent observatories. Therefore, hoax believers would not be part of the debate, but would just occupy their usual little niches on the internet, so I wouldn't worry about them.) /phpBB/images/smiles/icon_wink.gif

<font size=-1>[ This Message was edited by: Chip on 2002-07-03 20:40 ]</font>

beskeptical
2002-Jul-04, 12:48 AM
I always wondered when the first experiments were carried out on Mars to look for life, why the result of rapid oxidation was then assumed to be non-organic.

I may have the details wrong here but my fuzzy recollection is that they were looking for oxygen or something to form that was to indicate life. The result was what one would expect with life but the reaction was too much too fast or something.

I'd like to find out from the knowledgable posters I know are reading this what those fuzzy details are. /phpBB/images/smiles/icon_smile.gif

nebularain
2002-Jul-04, 03:06 AM
Of course there's life on Mars! Haven't you heard of Marvin - and his diabolical scheme to destroy the Earth? Why do you think all those probes we sent to Mars kept disappearing? Mathematical error?! Hah! What a cover-up! We knowthey were blown up by Marvin.

/phpBB/images/smiles/icon_lol.gif /phpBB/images/smiles/icon_biggrin.gif /phpBB/images/smiles/icon_lol.gif /phpBB/images/smiles/icon_biggrin.gif /phpBB/images/smiles/icon_lol.gif

beskeptical
2002-Jul-04, 09:21 PM
On 2002-07-03 23:06, nebularain wrote:
Of course there's life on Mars! Haven't you heard of Marvin - and his diabolical scheme to destroy the Earth? Why do you think all those probes we sent to Mars kept disappearing? Mathematical error?! Hah! What a cover-up! We knowthey were blown up by Marvin.

/phpBB/images/smiles/icon_lol.gif /phpBB/images/smiles/icon_biggrin.gif /phpBB/images/smiles/icon_lol.gif /phpBB/images/smiles/icon_biggrin.gif /phpBB/images/smiles/icon_lol.gif



I have to admit to having one brief thought that the first probe to crash that was to take further pictures of the 'face' was not accidental. Hmmm... was it Martians or the US Gov.???? /phpBB/images/smiles/icon_lol.gif

<font size=-1>[ This Message was edited by: beskeptical on 2002-07-06 01:59 ]</font>

traztx
2002-Jul-05, 03:14 PM
On 2002-07-03 14:46, David Hall wrote:


On 2002-07-03 14:29, traztx wrote:
A. 60
B. 0

So what are you going to do with the other forty? Make some other side-bet? (We find some of Hoagland's glass towers there for example) /phpBB/images/smiles/icon_biggrin.gif


I think we'll find not life, but death. What I mean is... dead/frozen microbes preserved in the ice or floating in the subeuropanean sea (coined word based on "subterranean"). I'd bet that other $40 they are interstellar.

Bacteria can actually survive the extreme conditions of cold and vacuum. I believe the easiest way to colonize other stars is to send spores and let nature take its course. Then we have to wonder if life began on Earth, or was it seeded?
--Tommy

DaveC
2002-Jul-05, 06:10 PM
On 2002-07-05 11:14, traztx wrote:

I think we'll find not life, but death. What I mean is... dead/frozen microbes preserved in the ice or floating in the subeuropanean sea (coined word based on "subterranean"). I'd bet that other $40 they are interstellar.

Bacteria can actually survive the extreme conditions of cold and vacuum. I believe the easiest way to colonize other stars is to send spores and let nature take its course. Then we have to wonder if life began on Earth, or was it seeded?
--Tommy


If the only lifeforms dicovered originated from another planet, it wouldn't be surprising if they were all dead. The chances of a lifeform that was adapted to a certain environment on its point of origin landing on a new planet with precisely the right conditions for it to survive are pretty slim. Even if that planet had the right conditions somewhere, it is not likely that's where the alien lifeform would land.
Life is resilient and adaptable for sure, but it can't adapt overnight to an environment that is totally alien. If there's any life (or residues of life) discoverable on Europa, my bet would be that it had to have originated there. A few bacterial colonies from another star system would be virtually impossible to find unless they had thrived and multiplied - and if they did, there is no reason to assume they wouldn't be continuing to do so.

David Hall
2002-Jul-05, 06:21 PM
If any living spores/bacteria/fungi/whatever were found on Europa, or any other planet for that matter, how would we be able to determine it came from another star/planet/place? If it managed to survive and adapt to conditions on that planet, it would basically be indistinguishable from an organism that arose there. Unless,perhaps there were an already in-place ecosystem to compare it to and it shows totally unexplainable differences to it.

But then, how could you tell that that biosystem didn't originate from another place also? /phpBB/images/smiles/icon_smile.gif

Donnie B.
2002-Jul-05, 08:24 PM
This discussion seems to be making a back-door approach to the "Intelligent Design" hypothesis.

Perhaps down in the deepest, most ancient segments of DNA we'll find a sequence that reads, "Made on Altair 6". But I doubt it.

However, if an intelligent ET wanted to seed the galaxy, maybe the simplest way would be to engineer spores that can survive long deep-space exposures, release them by the gazillions into nebulae, and then wait for star systems to come sweeping through on their normal paths around the galactix nucleus. Make enough of them, and every planet that comes along will get a good dose, and some might fall on "fertile ground".

But as has already been pointed out, after that each world's evolution would go its own way... so eventually you'd be hard-pressed to tell the difference between "native" and "seeded" worlds.

traztx
2002-Jul-05, 09:02 PM
On 2002-07-05 14:21, David Hall wrote:
If any living spores/bacteria/fungi/whatever were found on Europa, or any other planet for that matter, how would we be able to determine it came from another star/planet/place? If it managed to survive and adapt to conditions on that planet, it would basically be indistinguishable from an organism that arose there. Unless,perhaps there were an already in-place ecosystem to compare it to and it shows totally unexplainable differences to it.

But then, how could you tell that that biosystem didn't originate from another place also? /phpBB/images/smiles/icon_smile.gif


Good points. Our system is made of interstellar stuff, so it would definitely be hard to tell the difference! Maybe not as hard for someone born 500 years from now, though. Some clues:
1. Microbes and encasing material are made from isotopes that are very rare not only on Europa but the solar system at large.
2. Biologists are able to revive the microbes and get them to replicate only in a lab environment that is very alien to any of our planets/moons.
3. The microbes have photosynthetic features that don't make any sense in our system, but work very well in a system bathed in x-rays or some other spectra uncommon here.

If interstellar microbes found our system to be fertile enough to live (before any local life was around to compete), then their offspring would be made of our isotopes, adapt to our environment, and we would never know the difference.

But if they came to a sterile place and couldn't survive and were left in a well preserved environment, then maybe we have a chance.
--Tommy

traztx
2002-Jul-05, 09:24 PM
On 2002-07-05 14:10, DaveC wrote:
A few bacterial colonies from another star system would be virtually impossible to find unless they had thrived and multiplied - and if they did, there is no reason to assume they wouldn't be continuing to do so.


That's a very good argument. The needle is microscopic and the haystack is the size of Europa. Is it too late to ask for my $40 back? /phpBB/images/smiles/icon_smile.gif
--Tommy

DaveC
2002-Jul-05, 09:42 PM
On 2002-07-05 17:24, traztx wrote:
That's a very good argument. The needle is microscopic and the haystack is the size of Europa. Is it too late to ask for my $40 back? /phpBB/images/smiles/icon_smile.gif
--Tommy


Your $40 is gone. Can't change your bet just because the long shot horse is five lengths ahead 10 meters from the finish line.

beskeptical
2002-Jul-06, 06:13 AM
The major discovery about life around undersea vents on Earth is that the critters use chemical energy rather than photosynthesis. The implication is that life exists in much broader parameters than was previously believed.

I don't know whether planetary scientists are betting on Mars over Europa or vice versa. I think what is getting attention is that both planets have at least the potential for conditions where life can exist. In the past, we had tended to rule out the possibility of life within the solar system because there were no planets with conditions thought to be necessary for life.

Those pesky narrow minded scientists again. Now they're all scrambling to change fields: Planetary science instead of geology, astrobiology or something like that instead of biology, ..... /phpBB/images/smiles/icon_biggrin.gif ... should be fun to see what's next.

m1omg
2007-Jun-09, 09:30 PM
1.100 SK
2.20 SK

I am pretty much sure about the ocean...also the life is very probable for me, if some carbon sulfur nitrogen..compounds from the underwater volcanos are there than life is very probable if some great cataclysm did not happened..even if there is a bit hostile envirment (dark, no oxygen in the water) I belive that life could happen here, because I think that adverse conditions will HASTEN the evolution of the life...I will bet 1 Sk on multicellulars..

Occam's Shaving Cream
2007-Jun-09, 10:01 PM
About 10 years ago, in school, we got a group assigment to make a page from a newpaper from 2080. I've still got a copy around here somewhere.

One of our predictions was that single cellular life was discovered in the oceans of Europa (the others included cloning a dodo and a zero-g sports event).

I wouldn't actually bet on it though... But if they do live there, -so we predicted- some sucked nutrients from the ice (by growing threads into the ice) and others would concentrate near fissures in the ice to capture some solar energy. We even described a species that fed off chemicals near submerged vulcanic vents rather than pick sun light as energy source.

However, I'll bet 100 euros on Europa being a lifeless ball of ice, and I'll want my winnings by 2080. (If I'm still alive)

m1omg
2007-Jun-09, 10:08 PM
well 1 euro = about 31 SK
And why Europa being a lifeless ball of ice?

Occam's Shaving Cream
2007-Jun-09, 10:48 PM
The conditions on Europa just don't seem right. It's well beyond the habitable zone ("Goldilock's zone"). The liquid water is near freezing. Sure, we know of a lot of 'extremophiles' -bacteria that can prosper in extremely hostile environments- on Earth. But my personal take on that matter is that these are the descendents from earlier, less adapted surface dwellers. Those ancient bacteria have had quite some time to colonise the deep sea, deep underground, near aquatic vulcanic vents to eat chemicals, and even in the cooling water of nuclear plants.
I don't think an extreme environment like Europa is likely to spawn life, but existing life could probably adapt to such an environment (should we want to seed it with genetically manipulated seeweed or algea or something). I think it's a dead snowball.

m1omg
2007-Jun-09, 10:49 PM
The conditions on Europa just don't seem right. It's well beyond the habitable zone ("Goldilock's zone"). The liquid water is near freezing. Sure, we know of a lot of 'extremophiles' -bacteria that can prosper in extremely hostile environments- on Earth. But my personal take on that matter is that these are the descendents from earlier, less adapted surface dwellers. Those ancient bacteria have had quite some time to colonise the deep sea, deep underground, near aquatic vulcanic vents to eat chemicals, and even in the cooling water of nuclear plants.
I don't think an extreme environment like Europa is likely to spawn life, but existing life could probably adapt to such an environment (should we want to seed it with genetically manipulated seeweed or algea or something). I think it's a dead snowball.

Volcanos warm that water.Actually, that volcanic chimneys must spew hot water rich with various molecules.

Occam's Shaving Cream
2007-Jun-09, 11:09 PM
Volcanos warm that water.Actually, that volcanic chimneys must spew hot water rich with various molecules.

If it were that simple, we would have recreated it in a lab by now. Don't get me wrong here, I'm pretty sure that out there replicating lumps of matter are filling up all sorts of unfamiliar niches in their version of an eco-system, but I don't think Europa is a likely candidate for that role. We're not likely to find 'just a bit of life.' Either the seas are teeming with all sorts of life forms or it's dead. And if we encountered the moon during a 'primordial soup' period, every water sample should probably contain living critters. A rare event would be if we sampled the water at one side, and life had JUST started on the other side.

And besides, are vulcanic vents really a stable source of energy for generations of creatures to evolve? Presumably they are without means of locomotion, untill they evolve flagellae. Should that vents die out within the billion years it might take that single celled group of creatures to become multicellular then the entire bacteria colony dies.

It's a dead chuck of ice (with some water).

m1omg
2007-Jun-10, 12:29 AM
If it were that simple, we would have recreated it in a lab by now. Don't get me wrong here, I'm pretty sure that out there replicating lumps of matter are filling up all sorts of unfamiliar niches in their version of an eco-system, but I don't think Europa is a likely candidate for that role. We're not likely to find 'just a bit of life.' Either the seas are teeming with all sorts of life forms or it's dead. And if we encountered the moon during a 'primordial soup' period, every water sample should probably contain living critters. A rare event would be if we sampled the water at one side, and life had JUST started on the other side.

And besides, are vulcanic vents really a stable source of energy for generations of creatures to evolve? Presumably they are without means of locomotion, untill they evolve flagellae. Should that vents die out within the billion years it might take that single celled group of creatures to become multicellular then the entire bacteria colony dies.

It's a dead chuck of ice (with some water).

Because of the tidal flex, these volcanos are pretty stable and erupting imo.

m1omg
2007-Jun-10, 12:32 AM
And who said that we found "just a bit of life".I agree with you in that if there is a life on Europa, then it will be everywhere in it's water.But why that life shouldn't start here?

transreality
2007-Jun-10, 01:12 AM
There might be too much radiation in the proximity of Jupiter to allow life to be viable; is there enough ice and water to provide a shield?

Ronald Brak
2007-Jun-10, 02:19 AM
If it were that simple, we would have recreated it in a lab by now.

If your science department can afford a volcano, you have better funding than we do.

If all the bacteria living in the crust beneath you were brought up to the surface, you'd be at least knee deep in bacteria sludge. Over much of the earth there is more biomass beneath the surface than on it.


There might be too much radiation in the proximity of Jupiter to allow life to be viable; is there enough ice and water to provide a shield?

There is plenty of ice to act as a shield. A few meters should be fine and there are many kilometers of it available.

Noclevername
2007-Jun-10, 04:50 AM
If it were that simple, we would have recreated it in a lab by now.


Our attempts have been extremely limited in numbers and time, variations attempted, and amount and type of materials and energy involved compared to the conditions found in nature. Several billion years of planetwide trial-and-error (or moonwide, in this case) versus a handful of decades in a few labs? No comparison.

Occam's Shaving Cream
2007-Jun-10, 09:38 AM
Urg, I just knew that line about creating life in a lab would not go well. :doh:

Yeah, sorry, not a good comparison. I'm just exaggerating a bit to get my point across. Like so:

Liquid water is presented in the media almost as a guarantee that life WILL MOST LIKELY BE THERE. What, ice on the moon? Then these moonrocks are crawling with life! Erosion on Mars? Probably caused by rivers TEEMING WITH LIFE. What, there is a chance that there is liquid water on Europa? Pack your fishing rods guys!

Sure, I'd love to see alien life within my own life span, but I'm not getting my hopes up too much.

m1omg
2007-Jun-10, 09:52 AM
Urg, I just knew that line about creating life in a lab would not go well. :doh:

Yeah, sorry, not a good comparison. I'm just exaggerating a bit to get my point across. Like so:

Liquid water is presented in the media almost as a guarantee that life WILL MOST LIKELY BE THERE. What, ice on the moon? Then these moonrocks are crawling with life! Erosion on Mars? Probably caused by rivers TEEMING WITH LIFE. What, there is a chance that there is liquid water on Europa? Pack your fishing rods guys!

Sure, I'd love to see alien life within my own life span, but I'm not getting my hopes up too much.

There are ALL ingredients for life, not only water, like nutrients, minerals,heat...

Occam's Shaving Cream
2007-Jun-10, 11:09 AM
http://www.astrobiology.com/europa/images/europa.orca.2.jpg

m1omg
2007-Jun-10, 11:54 AM
http://www.astrobiology.com/europa/images/europa.orca.2.jpg

:D

Noclevername
2007-Jun-10, 06:09 PM
http://www.astrobiology.com/europa/images/europa.orca.2.jpg

"Free Willy VI: Whales In SPACE SPACE space space..."

Or:

"Captain, there be whales here!"

Noclevername
2007-Jun-10, 09:16 PM
And of course, those whales are aliens! (http://www.bautforum.com/showthread.php?p=1005578#post1005578)

Doodler
2007-Jun-11, 03:01 AM
Hmmm. Just to avoid confusion, I think a better adjective of Europa would be "Europan".

There's definitely life in Europe! /phpBB/images/smiles/icon_wink.gif


But is it intelligent? :think::razz:

On topic: If Europa does have an ocean, it probably has what it takes to form life.

Water - Present in vast quantities

Heat - Tidal warming from Jupiter, constant bombardment with radiation.

Chemistry - The satellite isn't ALL water, so the odds are some level of chemical activity is taking place at the transition between the ocean and the crust. Even if the crust of Europa has 10% of the activity of Io, its churning nicely by Terran standards. Plus the constant saturation of the crust would lube whatever passes for tectonics locally even more efficiently the oceans of Earth do here. This moon is rattled by harmonic resonance with two other Jovian moons, along with the tidal flexing from Jupiter, its got pretty decent conditions to motivate subsurface volcanism.

So to me, that's pointing pretty solidly in the direction of life, even if its barely to the trilobyte level

m1omg
2007-Jun-11, 06:12 AM
But is it intelligent? :think::razz:

On topic: If Europa does have an ocean, it probably has what it takes to form life.

Water - Present in vast quantities

Heat - Tidal warming from Jupiter, constant bombardment with radiation.

Chemistry - The satellite isn't ALL water, so the odds are some level of chemical activity is taking place at the transition between the ocean and the crust. Even if the crust of Europa has 10% of the activity of Io, its churning nicely by Terran standards. Plus the constant saturation of the crust would lube whatever passes for tectonics locally even more efficiently the oceans of Earth do here. This moon is rattled by harmonic resonance with two other Jovian moons, along with the tidal flexing from Jupiter, its got pretty decent conditions to motivate subsurface volcanism.

So to me, that's pointing pretty solidly in the direction of life, even if its barely to the trilobyte level

It is exactly what I think.

Occam's Shaving Cream
2007-Jun-11, 10:32 AM
And of course, those whales are aliens! (http://www.bautforum.com/showthread.php?p=1005578#post1005578)

They are indeed. And so is this one:


"Oh my god! They killed Willy!"
"You *******s!"
http://www.buddytv.com/articles/southparkmom.jpg

Noclevername
2007-Jun-11, 06:38 PM
"...And after that, NASA switched to using monkeys in their trial launches."

Doodler
2007-Jun-11, 08:54 PM
The petunias landed first.

Noclevername
2007-Jun-11, 10:11 PM
The petunias landed first.

No, no, that was a Sperm Whale! It's not visible here because the picture has been cropped.

Romanus
2007-Jun-15, 01:49 PM
I think it's too early to make any safe bets about Europan life; there are still many unknowns about the composition of its ocean, about subsurface activity, circulation, and the like.

I'm leaning to there being some kind of life, but if it exists I think it will be extremely primitive, maybe somewhere between the most complex virus and the simplest bacterium. Nothing I've read in scientific publications thus far indicates that Europa is likely to have a rich biotic environment.

Dr Nigel
2007-Jun-16, 09:52 AM
Didn't the primordial Earth have a predominately CO2 atmosphere until various evolutionary life cycles reversed the composition by locking up the CO2 in limestone deposits? Or something like that.

IIUC, the early Earth had a largely reductive environment. The atmosphere would have been mostly methane, ammonia and water vapour, with some CO2 and other stuff. Free oxygen (which is very reactive and hence does not have a long half-life) is a product of two processes. One is photolysis of water by UV light in the stratosphere (and subsequent photolysis of molecular oxygen leads to the production of ozone, which, in turn, protects the Earth's surface from harmful UV). The second is biogenic: photosynthesis using CO2 and water as substrates generates molecular oxygen.

The present amount of sea-level O2 in our atmosphere is almost entirely the result of photosynthesis.

Evidence that supports this idea comes from (inter alia) the existence of bacteria and archaea that are obligate anaerobes, i.e. oxygen is a poison to them. It is thought that metabolism based on oxidative phosphorylation initially arose as a means of detoxifying the toxic by-product of photosynthesis.

However, a consequence of the presence of molecular oxygen in the air is that our environment changed from being a reductive one to being an oxidative one. Hence, we have nitrogen instead of ammonia, the atmosphere contains very little methane and so on.


Also, doesn't water have free oxygen? Earth's oceans certainly do.

Water does not intrinsically contain free oxygen. The oxygen present in Earth's oceans and fresh waters has dissolved, either from the atmosphere, or as a result of its in situ production by aquatic photosynthetic life.


Life around our ocean's volcanic vents exists in the same conditions that could be present on Europa. If there is a liquid ocean on Europa, the implication is that volcanic activity would be the likely source of heat.

The very deep oceans, particularly around "black smokers", represent an anoxic environment, i.e. one with little or no molecular oxygen available. This is where we find life forms that use alternative means to acquire energy - the biochemistry of microbes in these places is often focussed on iron and sulphur rather than oxygen to produce energy.

The volcanic vents are more than a source of heat - they are a source of chemical substances that can undergo reactions that may be coupled to other processes in order to harness energy.