Stardust

[Laika]

Billy T,

Simple life is probably very common. I.e. better than a 50/50 chance on at least one orbiting object in every solar system.

Do you arrive at your figure from the rapid appearance of terrestrial life, or is there another basis for it?

To advance to more complex, but still single-cell forms (Those with considerable internal structures providing unique services to the organism.) is highly probable at least on thousands of objects in each galaxy.

I agree that prokaryote-like life is likely to be more common than eukaryote-like life, but the subject seems too speculative to justify the term "highly probable", given the single example we currently have.

Ophiolite,

Interplanetary biological transfer via ejecta sits comfortably with me. I can almost accept the possibility that relatively unprotected cells could survive interstellar journeys. However, I don't see how life could have originated in the interstellar environment, given the lack (I assume - this subject is not my forte) of large surface areas for the accumulation and concentration of the requisite molecules. To me, panspermia, used as an explanatory principle for terrestrial life, seems absurd. Why move the problem of genesis to a seemingly hostile environment from a demonstrably benign one if the necessary raw materials were common in both?

If I've erred at all in my reasoning, be gentle. Remember I'm strictly a layman in this area.

 

[Billy T]

Billy T, Do you arrive at your figure from the rapid appearance of terrestrial life, or is there another basis for it?
I agree that prokaryote-like life is likely to be more common than eukaryote-like life, but the subject seems too speculative to justify the term "highly probable", given the single example we currently have....

I am currently reading a Portuguese translation of Rare Earth by Peter D. Ward & Donald Brownlee*. I recommend it on this subject, and most of my views have been at least reshaped by it to some extent.

Life in very simple forms may have had several independent starts on only Earth. I.e. probably several different forms locally formed in the depths of the ocean without using oxygen to convert chemicals from the numerous volcanic vents (back when the radiogenic heat from deep Earth was significantly stronger) into their energy system's source. (To them, sulphur tasted good, etc. and I bet they also "thought" H2S stinks.)

There is also the oxygen using form on the surface of the Earth, of which we are a part. I suspect that there may have been several of these also, until one (no doubt our origins) learn how to eat the others, so now the surviving forms all use DNA, and have a lot in common, etc.

I am defining life broadly:
Life is a self-reproducing system, which has at least one internal chemical process. (That gets crystals excluded)
There is reason to suspect simple life has originated on other objects orbiting the sun. If in our solar system very simple Life has arisen several times, I think it reasonable to guess it has at least a 50/50 chance of doing so in other solar systems.

I do not know how many solar systems exist in a typical galaxy, but and I am sure my "thousands in a galaxy" of examples of eukaryote forms is a very small fraction and thus a reasonable, perhaps very conservative, guess if the prokaryote type is as common as 50/50 in each solar system. As Adam Smith noted in his study of economic systems (and life really is one, in a general sense) there is a tremendous advantage to specialization of tasks. Surely "thousands" of the many billions of examples of prokaryote life in a typical galaxy discover this and become eukaryote forms.
__________________________________
*A local bar owner calls me a several times each week. He has a sign up in bar that offers free English lessons by “native speaker” (me). If convenient, when he calls, I go there, a 5-minute walk, eat a fish and drink a few beers, for free. Ivo Korytowski is one of about 12 regular customers who translated the book, but wants to speak English better. A couple of the “want-English-practice” customers have actually improved their spoken English, but not Ivo, who laughs most of the time. We all have great fun in spontaneous discussions and joke telling etc. in mixed languages, especially when three or four are present and half-drunk. The Portuguese version of Book is ISBN 85-352-0706-6.

 

[cyber_indian]

What you're talking about is called black smokers, white smokers and lost cities and are a type of hydrothermal vents(there other types like geysers and hot springs) they're all habited by Archaea and are the first point of the food chain, meaning that they create biomass from simple chemicals. What hydrothermal vents do is introducing abundance of nutrients by circulating water next to magma cracks.
That same Archaea live in absence of oxygen, they also live in our intestines and are the reason we fart(methanogenesis).

According to science books Archaea is a middle point of the evolution(between Procariotes and Eucariotes), somehow Archaea never evolved. My believe is that Archaea is the source(according to books it's Procariotes) and divided to "vital" Procariotes and then to Eucariotes. Why vital because without Bacteria live on earth would have ceased to exist in several years. And are simplifyed as much as possible the the task they need to do.

Also Archaea is not only chemosynthetic, but also the one specialized in harsh enviroments.

 

[DwayneD.L.Rabon]

If the human body and life is considered to be 90 percent water it is then 90 percent cosmic sensitive, which leaves the remaining 10 percent. 5 percent carbon, 2.5 percent sulfur, 1.25 percent sodium. 1.25% potassium and 1.25 phosphours and 1.25 the reminder. At this assumption.........
Humans are subject to
90 % Cosmic infulences
3.75 % Galaxtic infulences
5 % Solar infulences

Undoubtably we know from observation trial and error that carbon is the main substance of human structure. Carbon being responsive to the events of our solar system shows that planetary organization is cheif in the structure of life. carbon is followed by those atoms that are galaxtic sensitive which seems to be a intermediate medium for carbon formations, both of the solar and galaxtic sensitive atoms are engulfed in the stable medium of the cosmic sensitive atoms ( water, H2O).

Appearntly there is a big difference between water and carbon in life forms, comparing the two one is 90% and the other 5 %, which defines that planetary(solar) motion is pivotal in the formation of life. water is a completely cosmic sensitive chemical, but is subject to solar fomation in chmeical form, CH2,CH3 and so on are solar and cosmic senstive chemicals but are subject to solar formation in chemical form. All chemicals are subject to solar formation events wheather they are cosmic, galaxtic or solar senstive atoms, this is simply the rule of proxcimity of force, simular to the effect of the moon verses the sun in effect on tideal motion where in the moon has a effect 11 times stronger than the sun. even so atoms are still responsive to the polarity be it cosmic, galaxtic or solar. Undoublty carbon is the structure of life as it is not only solar senstive but governed in chmeical formation by the solar system.
At 90% water is defined complety as a cosmic senstive polarity that is the medium of the human body, appearnlty life reqiures the lift and or energy signiture of the cosmic polarity, the accleration and unit of induction of this polarity are abundant and stable, another chemical such as one that was galaxtix would not be as stable, so it can be seen that water provides stabltiy and lift to carbon life.

Compare the earth to that of humans
____EARTH_____________________________HUMANS
46.557 % Cosmic Sensitive...................90 % Cosmic infulences
15.68% Galaxtic Sensitive.....................3.75 % Galaxtic infulences
36.51% Solar Sensitive.........................5 % Solar infulences

There seems to be a signifcant difference, so what could onbe exspect to find on a comet???

DwayneD.L.Rabon

 

[DwayneD.L.Rabon]

Perhaps helium would have to be the medium to supply the stabltiy of a life form on a comet.

DwayneD.L.Rabon

 

[DwayneD.L.Rabon]

or Iodine

 

[superluminal]

The formation of life requires liquid water...

Why are we so sure of this? Without knowing the detailed mechanisms of the formation of self-replicating, evolution-prone molecules, how can we be so sure? Because we have one good example of a planet with life that needs water to survive? Admittedly, the facility with which carbon-based molecules in water tend to form complex structures is impressive. But the whole water chauvinism thing smacks a bit of religious pronouncements...

 

[Mr Anonymous]

You basically need some form of relatively nonreactive medium in which chemical interaction can take place between individual chemical elements and not the environment in which they are in - unless its an oxidisation process.

Water is one of the most stable states O² can be stored in without it necessarily going nuts with everything else, but readily there if needed. Hence the importance of water.

In an anhydrous model you'd have to find something else which performed the same function. It would be more adventurous, but would it necessarily be at all likely?

 

[Hercules Rockefeller]

Why are we so sure of this

We can be reasonably sure of this due to an area of science known as “chemistry”. Water has unique properties that are largely a result of its simple composition and structure. Water is polar and, thus, more substances dissolve in water than in any other liquid. For this reason, water is often called the "Universal Solvent." The ability of water molecules to quickly break and re-form hydrogen bonds gives it a property called cohesion. Water has a high surface tension, high heat capacity and high latent heat of fusion. Quite simply, there is no other liquid that could possibly provide all the biochemical reaction conditions for all the various organic molecules that we know are associated with life on this planet. There is no other liquid in which organic molecules can react so efficiently. So it is commonly stated that water is essential for life as we know it. We cannot be 100% sure of this, but no science is 100% certain. A theory is only as good as the observations that underpin it. If you want to posit some other liquid in which biochemistry as we know it could produce life, then do please go ahead.

But the whole water chauvinism thing smacks a bit of religious pronouncements...

Nonsense. That was a rather foolish thing to say. It’s got nothing whatsoever to do with religion. It’s got everything to do with chemistry.<P>

 

[cyber_indian]

Who said something about religion ?

Encyclopedia:
Chauvinism is extreme and unreasoning partisanship on behalf of a group to which one belongs, especially when the partisanship includes malice and hatred towards a rival group. The term is derived from Nicolas Chauvin, a soldier under Napoleon Bonaparte, due to his fanatical zeal for his Emperor. Nicolas Chauvin was injured, wounded 17 times in the Napoleonic Wars but nevertheless he continued to fight for France.

Talking about Chauvinists ... the worst ones are Darwinists and Intelegent Design-ists if you ask me - that's one realy ugly war ...

 

[superluminal]

We can be reasonably sure of this due to an area of science known as “chemistry”. Water has unique properties that are largely a result of its simple composition and structure. Water is polar and, thus, more substances dissolve in water than in any other liquid. For this reason, water is often called the "Universal Solvent." The ability of water molecules to quickly break and re-form hydrogen bonds gives it a property called cohesion. Water has a high surface tension, high heat capacity and high latent heat of fusion. Quite simply, there is no other liquid that could possibly provide all the biochemical reaction conditions for all the various organic molecules that we know are associated with life on this planet. There is no other liquid in which organic molecules can react so efficiently. So it is commonly stated that water is essential for life as we know it. We cannot be 100% sure of this, but no science is 100% certain. A theory is only as good as the observations that underpin it. If you want to posit some other liquid in which biochemistry as we know it could produce life, then do please go ahead.

Yes, yes, yes. Had several chemistry courses. Understand the uniqueness of water.

Please reflect on this paragraph:

Quite simply, there is no other liquid that could possibly provide all the biochemical reaction conditions for all the various organic molecules that we know are associated with life on this planet. There is no other liquid in which organic molecules can react so efficiently. So it is commonly stated that water is essential for life as we know it.

Do I disagree with any of this? No. But can I imagine the discovery of what appears to be "life" based on some other solvent, with some fundamental element other than carbon as its structural base? Sure. I am far from a chemist, but the very fact that we have only one example of a phenomenon with very little understanding of the origin of this phenomenon, and then say we are " reasonably sure of this " is in opposition to the scientific method itself. Would you not agree?

Nonsense. That was a rather foolish thing to say. It’s got nothing whatsoever to do with religion. It’s got everything to do with chemistry.<P>

Yes, I agree with this. Retract the religious statement.

 

[superluminal]

Who said something about religion ?

Encyclopedia:
Chauvinism is extreme and unreasoning partisanship on behalf of a group to which one belongs, especially when the partisanship includes malice and hatred towards a rival group. The term is derived from Nicolas Chauvin, a soldier under Napoleon Bonaparte, due to his fanatical zeal for his Emperor. Nicolas Chauvin was injured, wounded 17 times in the Napoleonic Wars but nevertheless he continued to fight for France.

Talking about Chauvinists ... the worst ones are Darwinists and Intelegent Design-ists if you ask me - that's one realy ugly war ...

With respect, I use the word 'chauvinism' in the sense of a fairly unreasonable bias toward something. I happen to think that "water bias" (better?) is a fairly unsupportable position from a strict scientific perspective. JMO.

 

[Laika]

Wow, the red rain story gets even more interesting. This paper elaborates on the biology of the apparent organisms. It even provides a means for the transfer from a planet's surface to interstellar space. Seems a bit like science fiction at the moment, but if only it were true...

 

[DwayneD.L.Rabon]

Ok here it goes,
the area of the comet must be 11,619,687 cubic ft.(density 5.5) and have a weight of 174,295.3 tons to support structure of simple rna bases and the chromsome; of size simular to the human chromosome of 263,000,000 bases. in other words duplication of chromsosmes could take place possibly some cell formation, but no differential of cell types. so it would be a jelly, or a bacteria. but it seems that the out come would be more like a consistant chemical reaction such as the production of a given chemical formation, possibly a complexed carbon molecule.
As the life form is the result of the contents of the comet, it would have to depend on what element could act as the strutural formation, and which could act as the medium of transfer.

If the comet was solid tungsten at normal density the comet would have to have a area of 206,323.2 cubic ft. the difference in area undoubtly would change the size of the cell if it where to exist, and or change the volume of chemical produced.

As suggested by someone else organic molecules have been found in comets or asteroids?, that would seem consistant with the the nessacary mass and area required for support of rna type molecules if it where to exist on a coment.
Because of the large number of atoms that are solar senstive(polar) i would suppose that as long as they are bindable with a cosmic senstive atom a amorphous compund could always be present, haveing many sub-form chemicals of the same base consituents, and for that matter several such amorphous compounds.
Seems as well though that this would only occur at the surface of the comet, and in space at distance from the coment would crystalize and break apart.
At last it seems that comets might have a less stable orbit, and travel through to many solar atmospheres to support chemical life. Earth in contrast as a stable orbit and a fixed number of solar atmoshere and a reasonably consistant rate of travel these fixed circumstances are systematic in there relation to the solar bodies which effect the polarity of carbon, a coment in contrast has more varibles with motion so polarity of carbon would have no reasonable consistant order.

DwayneD.L.Rabon

 

[superluminal]

What does the size of the comet have to do with its ability to harbor simple organic compounds???

 

[DwayneD.L.Rabon]

Well simple organic chemicals would seem to form regardless of the mass or area of the comet, as chemical formation is a event of solar sensitiveity, and planetary effects of our solar system. but the area would effect the rate and volume of production of the chemical. The area is like the container? in which a chemical reaction occurs. it is the area of which the chemical must make response. when the container is full there is no more room for chmeical formation, or the type of chemical changes.

Dwayne D.L.Rabon

 

[Ophiolite]

However, I don't see how life could have originated in the interstellar environment, given the lack (I assume - this subject is not my forte) of large surface areas for the accumulation and concentration of the requisite molecules..

I envisage loose aggregations of the more solid material as mini-comets. These, and asteroids, appear to be much more porous and insubstantial than originally thought, thus providing a substantial network of interlinked surfaces, protected from radiation and with the possibility of local temperatures benign enough to permit liquid water.
The prebiotic phase is well catered for in the interstellar gas clouds in general.
In both cases it is the shear total volume of material within these clouds and conglomerations throughout the galaxy that offers multiple order of magnitude increases in the chance of life getting a start.

To me, panspermia, used as an explanatory principle for terrestrial life, seems absurd. Why move the problem of genesis to a seemingly hostile environment from a demonstrably benign one if the necessary raw materials were common in both?

I argue for moving it to the interstellar medium because I suspect that is where it occured. In short, we should follow the evidence. Life started suspiciously rapidly on Earth: ergo, it may have come here from elsewhere. Benign environments can be envisaged in interstellar space (and remember I mean benign for an extremophile, not a tourist on the beach in Spain): ergo, life may have originated there.

If I've erred at all in my reasoning, be gentle. Remember I'm strictly a layman in this area.

I am just an enthused amateur. I could be wrong. I probably am, but it is instructive to speculate.

 

[Laika]

But if life is truly ubiquitous in our galaxy, shouldn't it be settling through our atmosphere every time we pass through a comet's orbit?

 

[Ophiolite]

Yes. It should. Hoyle and Wickramasinghe proposed high altitude balloon experiments to test this. Bacterial spores have been found at high altitude before, but always assigned an Earthly origin. Application of Occam's razor would support that interpretation. They had proposed controls to account for terrestrial contamination. [I don't recall what they were, or how rigorous.] The project never got funding.
The problem is this: if you don't think life could comes from space you wont go looking for it; if you don't go looking for it, then a serendipitous series of events will be necessary before you discover it.

 

[Laika]

I don't suppose that Stardust has collected enough cometary debris for us to expect life, but if there is life to be found, maybe Rosetta will find it in 2014.