Life on Jupiter

[stevirobbo]

I'm not sure where you got those figures, but yes, whilst a protein spontaneously assembling is quite unlikely, consider the analogy of "mount improbable" used by Richard Dawkins.

Whilst leaping the face of a mountain in one go is very unlikely, so much so that you could say it is impossible, it is possible to climb it with a succession of smaller steps, each of which is perfectly natural, yet the cumulation of which would be impossible to achieve in one go.

a protein spontaneously self-assembling may indeed be nearly impossible, but a series of very probable events can lead to it. The Miller-Urey experiment showed that amino acids form within hours when sparks are introduced into an environment simulating the early Earth. the leap from a set of amino acids to basic proteins is not a large one, and Earth had a few hundred million years, not a couple of hours in a test tube!

It depends on the relative size of the subjects, if the mountain was small and the animal or human big then he could jump over the mountain for example small stones are mountains to the insect worlds and yet they have no trouble at all leaping over them, in fact they leap over things hugely bigger than the highest mountains to us, evolving better, stronger mustles in our legs may help one day.

[MikeWilson]

This is a very interesting topic indeed!

I find comparing earth's orbit to the sun in some way to a "Goldilocks zone" (not too hot, not too cold, but just right" is backwards reasoning. Of course the ecosystem of the earth is just right for us because it was the environmental pressures from this planet's ecosystems that drove natural selection to produce many lifeforms including us.

The earth is not always hospitable to life. Most of it, in fact, is wild and untamed and without some form of reliable shelter, food (and a manner in which to process it) and water, none of us would survive. Furthermore our climate has changed dramatically in the past (e.g. ice ages) and is likely to again. Furthermore, in earth's early hot and violent venus-like history there was probably no life at all.

To suggest that the earth is in a goldilocks zone is equivalent to suggesting that the human hand must have been made for a glove since the hand with it's five fingers fits so perfectly inside. It could not have been any other way.

Organic compounds have been found widely across the cosmos - including on extra solar planets (planets outside our own solar system). We find organic compounds on a comet; NASA collected samples from it's tail while it was still in flight and returned the samples safely to earth. Life may well be abundant in the universe.

It's all postulation, of course, but there's no reason to suggest that earth is in some goldilocks zone.

However it's the only planet which we have adapted to and I wonder if we will end up f***ing things up here so bad that in the future, trying to find somewhere else to live, we get stuck between a rock (pardon the pun) and a hard place.

[daneel]

Seems to me that Jupiter would be a great place for life to evolve. The atmosphere has lots of organics, lots of energy and lots of room. And there seem to be a lot of Jupiter-like exoplanets.

[MikeWilson]

Seems to me that Jupiter would be a great place for life to evolve. The atmosphere has lots of organics, lots of energy and lots of room. And there seem to be a lot of Jupiter-like exoplanets.

Hi Daneel (I think we met at Kelling Heath?),

I'd like to agree, but how are we going to detect life without getting awfully (and uncomfortably close) to Jupiter?

I presume NASA will conjure up a probe of some description to plunge into the planet and keep radioing back data until it's lost They're rather good at littering foreign planets with probes, aren't they?

[Wattsy]

a lot of the theories i've heard seem to assume that life has to be constructed of proteins and amino acids, carbon based and water dependant i saw an episode of stephen hawkings universe earlier where he argued that life could be silicon based or based on any other element only restricted by the laws of physics not necessarily by the laws of nature (on earth). i think alien life is most likely to exist as rafts of single cell organisms like bacteria myself

[brianb]

life could be silicon based or based on any other element only restricted by the laws of physics

Precisely.

Physics dictates that only carbon is good at making the sort of long chain molecules that appear to be necessary for life. Silicon is next best but it just isn't good enough to make self replicating molecules.

[toml42]

It's interesting to note that in the universe as a whole, Carbon is about 7 times more common than Silicon, however on the Earth, Silicon is about 1000 times more abundant than Carbon.

The Earth then is a practical oasis of Silicon, yet it is Carbon that forms the basis of all our living creatures. This suggests that either Silicon based life is either improbable or not viable, or that it cannot exist in our temperature range.

[FraserClarke]

Brian and Tom's points a very good; in it's very basic forms life is quite well described by chemistry and physics. Yes, you *can* make life forms with things other than carbon, but it's a lot harder and therefore less likely.

Equally, liquid water is quite an unusually useful substrate for life to start in. It's a fantastically good solvent, meaning it allows all your component molecules to break down and move around and react with each other. It's also very odd in that the solid is less dense than the liquid form -- very useful in stopping your oceans freezing solid. It's also got quite a high heat capacity, so it's relatively stable environment.

So the anthropic principle (conditions are compatible with life because we're alive) doesn't really apply to the Earth's conditions. There are a lot of solid physical and chemical arguments about why having liquid water is pretty key for life to evolve. Yes, you can do it other ways, but they are harder ; and that means they are less likely to happen (not impossible of course, just less likely).

[brianb]

Silicon is about 1000 times more abundant than Carbon.

The Earth then is a practical oasis of Silicon

And there's far more nickel and iron than either of these.

Fact is, most carbon compounds are rather volatile. So they got evaporated off the inner planets when the sun was young and vigorous (radiating off its gravitational infall energy plus a bit from deuterium fusion) leaving rather more of the much less volatile silicon compounds which make up the rocks in the crust and upper mantle.

There is much more carbon (and nitrogen and oxygen) in the universe than there is of the heavier elements ... eventually the Sun will grow a helium core massive enough to start "burning" helium to carbon, but will never produce significant amounts of silicon or iron. Heavier stars - which do go on to produce iron, and eventually go supernova, recycling the outer layers back into the interstellar medium - also contain more carbon group than heavier elements at the time they go bang.

In any case, though the constituent which has the potential to make long chain molecules is certainly necessary, it's not sufficient. Earthly life depends just as much on hydrogen and nitrogen in particular, and a host of other elements to a lesser extent, as it does on carbon ... and is supremely dependent on water as a solvent enabling the chemistry to happen. At the sort of temperatures where carbon doesn't "work" but silicon might, you need to look for an alternate solvent ... and at those sort of temperatures you'd probably find that the planet had lost most of its hydrogen (& other light elements) anyway.

Unless it was very massive, like Jupiter ... but then the dense, deep, turbulent atmosphere would tear apart molecules "interesting" enough to be precursors to life as fast as they were assembled ... though it might be possible to engineer a lifeform that could survive and reproduce in the Jovian atmosphere, it would be a complex "device" including pressure sensors allowing it to maintain a safe environmental temperature & pressure & it's hard to see how such an organism could evolve. (On Earth the existence of solid surfaces bathed in organic nutrients would have allowed evolution to act on simple organisms until they became complex enough to survive floating free).

[Space Oddity6]

Found this, New Earth-like planet discovered | Science | The Guardian (actually stole it from a thread in the Astro Lounge) but it seems very interesting. What do people think? The estimates of the temperatures being between -12 and -31C are discouraging but just that; estimates.

What I find the most interesting and encouraging is what Steven Vogt says at the end, that there could be tens of billions of these planets in our galaxy.

Something else I've read is the suspected presence of 'Water-worlds.' Scientists believe that life is highly likely to be present on these planets. Seeing as on Earth, we find lifeforms beneath the ice at the poles, the existence of life on these planets would seem to be probable.

[MikeWilson]

Organic chemistry, yes; Self-replicating compounds, probably. Interesting life? Maybe. Exotic, tall, blue female aliens of dubious and frivolous sexuality? One wonders, but too much star trek can be harmful to the imagination!

[brianb]

The estimates of the temperatures being between -12 and -31C are discouraging

Don't panic; the black body temperature of the Earth is -15C ... the temperature is of course much higher in the tropics than in the polar regions, and the black body temperature underestimates the actual average surface temperature by around 25C due to the effects of greenhouse gases (principally water vapour).

[BobTheSaxon]

Well commented Tom. Lots of time and little steps is our best understanding of how life has arisen on earth. I believe the earliest steps towards life were molecules that produced copies of themselves - it's nowhere near what we would call life today. The simplest lifeform, or is it just a complex replicating molecular assembly, would be a non-enveloped virus e.g tobacco mosaic virus. But is it alive??

I think we need to be clear what we mean by life - I don't regard clouds of gases that feed of one another as life. I think the biologists have a definition of simple life that has seven elements to it (apparently known by the acronym MRS NERG - Movement, Reproduction, Sensitivity (i.e responding to external stimuli), Nutrition (feeing), Excretion, Respiration and Growth). Also, as life is chemically complex it will need a range of molecules (small and large) in order to exist. These will be made from the usual chemical bonds - and these can only exist within certain environmental limits (e.g. too hot and they fall apart). The larger molecules needed for life (e.g. proteins) are like little machines which to function must deform - if the temperature is too low they will not be able to deform, either because they are frozen lke ice, or if in water the water would be frozen and so prevent them deforming and also moving (dffusing) to places where they carry out their acions. Putting them in liquid methane (as on Jupiter) would prevent them folding into the correct shapes in the first place. A little to warm and they melt - denature - just like the white of your egg when you fry it.

So, life is complex and needs complex molecules (e.g. proteins) which, while made up of fairly simple building blocks (proteins are made of only 20 different types of amino acids linearly polymerised, there may be a few 100 to 1000s in a given protein) are forced into a unique folded and functional state by their interaction with the solvent (water) as they are made - so folding is sequence specific. And this is a very simplistic view of life - in reality it is far, far more complex. So I think there will be a miniscule number of environmens in which various life forms can arise. But in a huge universe... no doubt other life forms exist.

Happy musings,

Bob

[sammy1404]

Life couldnt exist on jupiter one because it is gas and has no official surface, two there is no water, three it is too far from our sun for life to exist, 4 it would be painful because of g lol. This is of course assuming that all life in universe has to be like us and dependent on carbon and other fundamental things which make life on earth but it really does seem that way to be honest id be surprised if we find a life form which is radically different to us, their tech maybe different but not their being.

[brianb]

Life couldnt exist on jupiter one because it is gas and has no official surface, two there is no water, three it is too far from our sun for life to exist, 4 it would be painful because of g

1, 3 and 4 are irrelevant - does a shark need there to be a "surface" to the sea? It always swims somewhere between the surface and the bottom. Distance to the sun is irrelavant to life on earth that lives in the deep ocean where light does not penetrate; the primary power source for life around the deep ocean vents is geothermal not solar. For an animal living in a fluid environment, gravity is irrelevant as the fluid makes the animal effectively weightless - hence the use of underwater training for astronaut EVAs.

Water as a liquid solvent is however critical to organic life.

their tech maybe different but not their being.

I can't get it out of my head that, here on Earth, we are rapidly being out-evolved by inorganic beings generated by our advanced technology. Give it a few hundred years and I can see that it is possible that "intelligent" robots may have replaced organic life. Such robots would not require water to support their form of life. I don't see how they could start to evolve without a helping hand from a technologically savvy organic life form, but once they're bootstrapped we'll no longer be required.

[JayLynch]

I think it is likely that Jupiter is, in fact, very much alive.

Not to be blunt, but it did evolve alongside the earth, have access to the sun, and, in fact, evolved in a pressure system much greater than the earth's. In fact, with respect to the elements, we cannot begin to imagine how different the world appears when the pressure is 54x. I hypothesize that life actually evolved equivocally faster on Jupiter, and that we simply have not developed the capacity or perspective to see it.

We have methane, an essential building block, ammonia (which only comes from elsewhere in space). An outer layer of frozen ammonia, indicating the preference of trying to convert as much sunlight into energy as possible. If there is ammonia, there must be nitrogen. We have hydrogen sulfide which breaks down organic matter where there is very little oxygen. There are phosphines, which are implicated on the ongoing debate of Chirality:

Homochiral polymers are required for life, so the probabilities must be compounded in a high pressure system. However compounded the probabilities are, even in the case of earth, the mathematics does not support the probability of forming one homochiral polymer of N monomers by chance = 2–N. The probability of forming a functional homochiral polymer is much lower. So we have to assume that homochiral polymers are becoming functional through as yet undiscovered processes, which occur regardless of probability.

We also have liquid hydrogen, which it is hypothesized is a superconductor. (~290 K) far higher than any other known candidate material. This comes from its extremely high speed of sound and the strength between the conduction electrons and the lattice vibrations. So, we have a highly conductive liquid metal ocean, the largest ocean in the solar system, just below the cloud cover. Aside from being conductive, liquid hydrogen can be used to propel and power things. We also have the presence of another common and conductive metal, Silicon. We have ethane, a product of methane, which is a produced by bacteria.

Also we must consider that the concept of "bacteria" on Jupiter means something very different. With such internal pressures, a biological structure is going to be based on different principles. Aside from basic survival, it will need to be composed of strong metallic protective material. We are not looking for houses, cities or earthly, anthropomorphic things, like balloons or birds, the pressure is such that everything is in motion, permanently. Life would have adapted to this by storing energy from atmospheric turbulence and force, and would have evolved to develop ways to navigate and harmonize with it.

On earth, the process of life is the continual refinement of the organism to adapt to the environment. The eventual destination of evolution is adapting entirely to your planet, as an organism which is fully compatible and perfectly suited for advantage. On Jupiter, those numbers are quite different, Basically we have to imagine life and evolution under a completely different set of initial conditions. We also have to consider that Jupiter has existed as long as the earth has, and has had access to much more energy. We know Jupiter receives sunlight because it's atmosphere is configured to maximize the little sunlight it does receive (25% of earth's, comparatively).

Given the density of Jupiter, the sunlight would never reach very far, but its impact would be felt and dispersed. We also know archaea on earth can flourish without sunlight by eating hydrogen sulfide.

The atmospheric pressure causes elements (which normally are found underground on as a gas on earth) to be suspended in the air, highly pressurized and liquefied in Jupiter. The diminished sun resource would be not a problem for these early life forms. They would be getting all the energy they needed from the planet's heat releasing process. With nothing solid, the planet's biosphere would resemble a large, apparently chaotic ocean, with extremes of speed, temperature and pressure that dwarf the gentle physical tranquility of our planet.

We also have polycyclic aromatic hydrocarbons (PAH), which, it is hypothesized that they were abundant in the primordial soup of the early Earth as well. They mediated the synthesis of RNA molecules, leading to RNA. We have an equivalently sized troposphere.

X-ray emissions are expected from astronomical sources which contain an extremely hot gas at temperatures from about a million degrees kelvin (K) to hundreds of millions of degrees (MK).

We don't have nearly those temperatures on Jupiter, but we still have a pulsating x-ray every 45 minutes from the poles. This x-ray was determined to be of random, inordinate length, but only that it pulses approximately every 45 minutes. This seems to be evidence of a natural process.

Theoretically, Jupiter could already be a highly advanced civilization which has simply evolved into gaseous forms to survive in the intensely physical, high pressure atmosphere.

Our current system of pressure enables us only to understand life from this perspective.

The complexity of some of the Jupiter's processes and the silicon and liquid hydrogen interactions could be a manifestation of future technology, or simply the distant-future result of life adapting fully and completely with its host.

Unfortunately the Galileo probe was destroyed before it could reach some of Jupiter's

more telling depths.

[lw24]

When our Sun eventually enters the 'Red Giant' stage of it's life cycle, it will expand. Due to this, will Titan, and Europa 'warm up' enough to allow life to evolve, survive and adapt?

I mean, the methane rain and methane lakes on Titan will surely turn to gas, as the temperature of the planet increases, and therefore the ice should melt making water. Is this enough for life to form on Titan.

Also, scientists are sure that Europa has a large ocean beneath its icy surface. If this ice started to melt, the ocean would be exposed to sunlight, and certain organisms which thrive off of sunlight would be able to survive and develop.

Pity we wouldn't be around to see it

Just my thoughts.

[fatwoul]

...Also, scientists are sure that Europa has a large ocean beneath its icy surface. If this ice started to melt, the ocean would be exposed to sunlight, and certain organisms which thrive off of sunlight would be able to survive and develop.

Pity we wouldn't be around to see it

Just my thoughts.

Wasn't it also suggested that volcanic vents at the bottom of the Europan sea could provide the energy gradient needed to support life? Rather like we have lobsters living around vents in our seas, whose food chain derives its energy from the vents entirely, with no sunlight at all. Europa wouldn't need to warm up for that, would it?

[MikeWilson]

Wasn't it also suggested that volcanic vents at the bottom of the Europan sea could provide the energy gradient needed to support life? Rather like we have lobsters living around vents in our seas, whose food chain derives its energy from the vents entirely, with no sunlight at all. Europa wouldn't need to warm up for that, would it?

I don't have a source for this but my understanding (from watching documentaries on the telly) was that those animals who live around those thermal vents had in fact evolved further up (and share a fairly close common ancestor with other prawns/lobsters, etc) and migrated down towards the vents, slowly adapting and losing vision.

[JulianO]

I don't have a source for this but my understanding (from watching documentaries on the telly) was that those animals who live around those thermal vents had in fact evolved further up (and share a fairly close common ancestor with other prawns/lobsters, etc) and migrated down towards the vents, slowly adapting and losing vision.

I think the jury is out on that. There are equally good lines of speculation that suggest life started at these black smokers and made their way up.

The early earth was a hostile environment, with hardly any free oxygen, there was a lot of UV light hitting it because of no ozone layer. Therefore delicate early reactions would likely be ruined by the UV light blasting things apart.

[Macavity]

Hardly scientific, but, given the difficulty of maintaining "bio-free" environments locally(!), I personally have a hard time conceiving of, "entirely sterile", planets. Bit like thinking "Big Bang", as encompassing the WHOLE of reality.

Despite past enthusiasm for "alternative life", based on homologue elements etc. (See Star Treck's HORTA), I sense the "reaction kinetics" are against it? Even "heavy" water has significant toxicity to "life as we know it" (Jim)...

[MikeWilson]

I think the jury is out on that. There are equally good lines of speculation that suggest life started at these black smokers and made their way up.

The early earth was a hostile environment, with hardly any free oxygen, there was a lot of UV light hitting it because of no ozone layer. Therefore delicate early reactions would likely be ruined by the UV light blasting things apart.

Very true and Wikipedia has this to say:

Günter Wächtershäuser proposed the Iron-sulfur world theory and suggested that life might have originated at hydrothermal vents. Wächtershäuser proposed that an early form of metabolism predated genetics. By metabolism he meant a cycle of chemical reactions that release energy in a form that can be harnessed by other processes.[19]

It has been proposed that amino-acid synthesis could have occurred deep in the Earth's crust and that these amino-acids were subsequently shot up along with hydrothermal fluids into cooler waters, where lower temperatures and the presence of clay minerals would have fostered the formation of peptides and protocells.[20] This is an attractive hypothesis because of the abundance of CH4 and NH3 present in hydrothermal vent regions, a condition that was not provided by the Earth's primitive atmosphere. A major limitation to this hypothesis is the lack of stability of organic molecules at high temperatures, but some have suggested that life would have originated outside of the zones of highest temperature. There are numerous species of extremophiles and other organisms currently living immediately around deep-sea vents, suggesting that this is indeed a possible scenario.

Source: http://www.pnas.org/cgi/reprint/87/1/200.pdf

I ended up on Wikipedia after searching for a common ancestor between the lobsters and prawns we all know and love and the ones that sit around the hydrothermal vents. They all look similar so probably share a close ancestor.

[JulianO]

I ended up on Wikipedia after searching for a common ancestor between the lobsters and prawns we all know and love and the ones that sit around the hydrothermal vents. They all look similar so probably share a close ancestor.

The prawns and lobsters would be relative newcomers. The original, and still those that tap the primary energy are bacteria/archea of which a form of is a good LUCA (last universal common ancestor) candidate.

[lexyastroman]

BBC News - Impacts 'more likely' to have spread life from Earth

Interesting bit of news that if life was found in jupiter's system it could have originated from earth? Perhaps the missing link to how life on earth started begins with lifeforms found in jupiter's system? Imagine if they shared the same genetic structure as us but evolved on another planet? Darwinism gone galatic that would be... Basically like life on earth but in a more hardened form.

[Anweniel]

I guess some(most) of the speculation regarding Jupiter will be quashed once/if the data from Juno mission is returned and analysed.

Love the discussion thread though much of the arguements have been surrounding the possibility of life forming and evolving in these unfamiliar and untested environments.

There is of course another possibility, a theory of panspermia. That life can be seeded into various regions of space from alien environments. Research has shown that in the depths of space simple life can exist on perhaps more likely on an icy comet, the low temperatures experienced can cause life to become dormant and buried beneath perhaps a thick layer of ice or rock have some protection from lethal radiation. Then as it comes to rest be reanimated and then adapt to more complex forms.

Bearing in mind this is still seated highly in speculation it does offer another theory how life can exist in seemingly inhospitable environments, however it is based on ideas we know, sucj as how life does exist here and in some pretty harsh environments. We know how life can seem to hibernate at low temperatures.

In all the trillions of places life could exist in our universe (or others) I would not be placing my bet on it not. As for Jupiter, I'm not sure we will find any life form that we recognise, thats not to say it doesnt exist just that if there is something there it will be so far removed from our expectations and definition of life that we are likely to miss it.

Of course I could always be spouting absolute rubbish its fun to speculate nevertheles