UEA Research Shows Oceans Vital For Possibility of Alien Life

An anonymous reader writes New research at the University of East Anglia finds that oceans are vital in the search for alien life. So far, computer simulations of habitable climates on other planets have focused on their atmospheres. But oceans play an equally vital role in moderating climates on planets and bringing stability to the climate, according to the study. From the press release: "The research team from UEA's schools of Mathematics and Environmental Sciences created a computer simulated pattern of ocean circulation on a hypothetical ocean-covered Earth-like planet. They looked at how different planetary rotation rates would impact heat transport with the presence of oceans taken into account. Prof David Stevens from UEA's school of Mathematics said: 'The number of planets being discovered outside our solar system is rapidly increasing. This research will help answer whether or not these planets could sustain alien life. We know that many planets are completely uninhabitable because they are either too close or too far from their sun. A planet's habitable zone is based on its distance from the sun and temperatures at which it is possible for the planet to have liquid water. But until now, most habitability models have neglected the impact of oceans on climate.'"

Comments

Correction

[halivar]

"Vital For Possibility of Earth-like Alien Life"

A lot of assumptions there.

Re:Correction

[Thruen]

I wish I had mod points. Every time I hear about planets not being able to support life, this is my first thought. While it's possible that there's no radically different life forms in the universe, until we actually go out and see it, we don't really know. I'm not even sure if we should call it unlikely until we've managed to examine the planets outside out solar system more closely. Don't get me wrong, I'm not expecting it and I'll be amazed if we find anything so different from ourselves, but I don't think we should rule out the possibility.

Re:Correction

[gstoddart]

but I don't think we should rule out the possibility

Not only shouldn't we, we simply can't, because we have no way of knowing.

There is no scientifically valid way to rule out life forms which are unlike our own, because we don't know what they would require or thrive on.

The same as when people say "but why aren't we searching for life which is unlike us", the answer becomes "because we don't know how". There's no basis on which to conclude anything other than "well, we couldn't live there".

At best, we can say a planet is uninhabitable by us, but we really cannot say it is uninhabitable by life we can't even imagine and which is significantly different from what we know.

Anybody who tries to tell you there is no chance of life as we don't know it existing someplace is saying much more than they actually know.

Re:Correction

[Iamthecheese]

Even on Earth there are a lot of creatures that can survive conditions far outside the normal range.

Re:Correction

[gstoddart]

If it is sub-intelligent, then it might meet some definition of "life," but would have no impact on life here.

Oh yeah, what if they're tasty? Some Cerulian maple-bacon pig or something. ;-)

But, more importantly, if we find life on another planet (or wherever), of any form, intelligent or not, that in and of itself would have a huge impact on life here even if we couldn't get there.

Because the answer to "is there life anywhere else" will have been answered, and the people who loudly say there is only life on this planet will be proven wrong.

And, if we know there's like here, and then confirm there's life elsewhere ... given the size of the universe, you would more or less have to conclude that life is pretty widespread.

Even if it was unintelligent, the discovery of life elsewhere in the universe would be utterly monumental in a lot of different ways.

To me, I don't think you can overstate just how big of a deal that would be. Because it would be a complete game changer in a lot of ways, and lay rest to the notion that Earth is singularly unique in that regard.

I just don't see such a discovery having 'no impact'. Not even a little.

Re:Correction

[the gnat]

I wish I had mod points. Every time I hear about planets not being able to support life, this is my first thought.

And every time a story about extraterrestrial life gets posted on Slashdot, several dozen people say exactly the same thing, as if they've had some brilliantly original insight that the scientists researching the subject missed. No one is explicitly ruling out the possibility that there are gaseous lifeforms living in the clouds of gas giants, or silicon-based rock monsters like the one in Star Trek. Hell, it would be a huge discovery if we found something like that. But since we're presently incapable of observing such lifeforms firsthand, and have no idea what we should be looking for at a distance of light-years, we have to settle for looking for the planetary "signatures" of temperature, oceans, oxygen content, etc. It may not satisfy the pedants, but it's still extremely difficult by itself. When we're capable of actually exploring other solar systems directly, then maybe we can start to look for fantasy lifeforms on frozen airless rocks and methane clouds.

Re:Correction

[K. S. Kyosuke]

There is no scientifically valid way to rule out life forms which are unlike our own

I'm pretty sure there are ways to constrain the range of possibilities. One obvious thing is that no life forms will most likely be based on xenon or gold because these elements don't really form the same kind of a wide range of interesting compounds that carbon does. The laws of physics (and chemistry) are the same pretty much everywhere, and just because our brains (and computers) are incapable of reaching more significant conclusions on this issue at this very moment doesn't mean that it's going to stay like that forever.

Re:Correction

[Anonymous Coward]

No one is explicitly ruling out the possibility that there are gaseous lifeforms living in the clouds of gas giants, or silicon-based rock monsters like the one in Star Trek.

Actually, we know almost all basic chemistry, and the range of (stable) molecules that silicon can form is orders of magnitude less than for carbon.
There is a lot of silicon to be found on/in the surface of our planet (over 900 times more than carbon), and yet lifeforms here didn't integrate it in their core chemistry. At most they used it to reinforce surface/skeletal structures.
It also doesn't readily form gaseous molecules like carbon does (CO2), which would help in energy cycles.

Re:Correction

[the gnat]

Actually, we know almost all basic chemistry, and the range of (stable) molecules that silicon can form is orders of magnitude less than for carbon.

Well, yeah, but I didn't want to offend the pedants even further. Unless the laws of physics (and therefore basic chemistry) are very different elsewhere in the galaxy, it's not unreasonable to think that carbon-based, liquid-water-dependent lifeforms are the most probable. In fact, I'd be willing to bet a tidy sum of money that the overwhelming majority of unique forms of life are not terribly dissimilar from ours as far as the underlying chemistry is concerned. They might be fantastically alien in all sorts of other strange ways, but they'll still be based on simple organic polymers. But this is still irrelevant to the discussion at hand, because even if there were different forms of life, we have no idea how we might detect them at astronomical distances.

Re:Correction

[khallow]

There is no scientifically valid way to rule out life forms which are unlike our own

1) Life will require energy flow. More fully, life will operate much like a heat pump tapping energy flow between a high entropy or temperature sink to a lower entropy or temperature sink.

2) Life will require an environment it can survive in. This story attempts to address part of that with the idea of climate buffering.

3) As K. S. Kyosuke noted in his reply, life will require some matrix capable of the complex morphological structures and behaviors that life will need to survive.

4) Life will need time or a shortcut (like a creator) in order to develop. Evolution-based life will need time (measured in generations) for adaptation to occur.

For example, let's take an isolated "rogue planet". First, it's an object massive enough to round itself under the force of its own gravity, but not massive enough to undergo fusion. Second, it's not orbiting a star and basically is slowly cooling down to the temperature of the cosmic microwave background (no external energy inputs of note). The driver for any life would have to be heat flow from the interior due to heat of formation and possible radioactive decay. The situation is contrived (but in a way that actually probably appears billions of times in nature, just in our galaxy) so that there is no other means to provide significant energy flow to the system.

Restriction 2) is rather simply solved since the environment is very stable over billions of years (unless the rogue planet happens to get too close to a star or runs into something).

Restriction 3) requires either complex chemistry (from elements other than hydrogen or helium) or structure from say possibly, the interaction of different phases of metallic hydrogen and electromagnetism at the core of a gas giant.

Restriction 4) means that if it's evolution-based life derived from abiogenesis, then it needs to be in a high enough energy flow over large enough volume so that enough generations can pass to evolve to a state where they can technically qualify as life (such as traits/information passed from past organisms to future ones). We don't know how big that would need to be, but bigger and older is better. Similarly, we would need the presence of complex structures, which are more likely in a high energy flow environment (eg, amino acids created by weather-induced lightning).

If it's creator-derived or evolved elsewhere and migrated, who knows. The resulting organism might be able to fuse deterium and/or helium 3 isotopes, for example. That allows for creation of higher weight elements too.

Re:Correction

[Immerman]

Hmm, now you've got me curious just what it would take. Let's see... human energy consumption in 2008 ~=144,000 TWh = 5*10^20 Joules
E = 1/2mv^2 (for negligibly relativistic speeds), therefore
m = 2E/v^2. And if we're looking to get to 0.1c that gives us...
m = 2*5e20/(0.1c)^2 = 1,112,650 kg

So given an acceleration system that requires minimal reaction mass, with the amount of energy we consumed in 2008 we could get a 1000 metric ton craft up to around 1/10 lightspeed. Eminently doable if we had the political will to attempt it, and the (few) passengers could reach the nearest stars in a single generation.

Of course for colonization with near-term tech we'd probably want to make large generation ships, which would increase the energy needs considerably. Still, a decent fusion reactor and some powerful ion drives should make it viable, and both of those are currently hovering on the edge of viability. And of course if we ever manage to find/make magnetic micro-singularities then mass-conversion reactors become an easy source of near unlimited energy, and such things become almost inevitable. Hmm, let's see: 5*10^20J/c^2 =~ 5,563 kg. Not too shabby, a 200:1 payload to fuel ratio to accelerate to 0.1c. Of course your reaction mass is going to dwarf that... and sadly Google won't cough up any thrust-to-energy ratios for a "radio drive" - I seem to recall they're expected to be terribly inefficient, but with mass conversion for power the lack of reaction mass might make it an acceptable option.

Swampland!

[TechyImmigrant]

This makes sense. The University of East Anglia exists in swampland that is slowly sinking while the sea is slowly rising. It's halfway to ocean already.

Extremophile

[khasim]

Extremophile

I'm thinking more along the lines of "Life that will use radio signals (or similar) to communicate in such a way that we have a chance of detecting them without either of us leaving our solar systems".

But that's a bit wordy.

Re:Extremophile

[i kan reed]

There's a couple things here:

1. Extremophiles evolved progressively to more difficult ecosystems. They came from organisms that could manage in chemically unreactive of mostly water/salt water. It's unlikely the precursors to life, like prions or unbound mRNA chains would've "made it" in arsenic lakes or boiling lakes. But some prokaryotes could manage in environments with a little arsenic, and evolution could work its magic.

Like the creationists say, getting something as complex and robust as a modern organism "randomly" would be a bit like a tornado blowing through a junk yard and assembling a car.

2. The utility of radio waves for communication wouldn't hinge much on the physic form of an organism, just something much like sapience.

Re:Not on Arrakis

[TechyImmigrant]

> BTW, if you averaged all the elevations on earth, none of it would be above the level of the ocean.

This would be true of any planet with any amount of surface water.
Given a perfect sphere, the water is just going to spread out and cover it.

You can't go around leveling the land without impacting the water level. They are linked.

Re:Not on Arrakis

[Your.Master]

This would be true of any planet with any amount of surface water.

This statement isn't true. The rest of your statements are true.

Consider a perfectly spherical planet with no surface water, but with an underground water supply not too far below the surface (eg. as Europa is hypothesized to be).

Now make it less smooth, eg. slam it with meteors such that there's no net loss in matter (possibly a slight net gain), but it's no longer perfectly smooth.

Now you have surface water on a planet with an average elevation higher than the water level.

Basically, any planet with surface water (or methane or whatever) and surface not-water is going to have an average elevation of water and an average elevation of not-water and they are likely going to be similar relative to the size of the planet as a whole, but there's no general statement you can make about which one is higher (there may be a probabilistic statement).

Re:Meaning of LIFE!?!?

[Immerman]

And how would you recommend we look for life of a kind we have no understanding of? We're still trying to figure out how to detect life-much-as-we-know-it if it's not jumping up and down and screaming (metaphorically of course). An example of a much easier problem: Suppose I know with absolute certainty that there's a specific thing in the room with you. Given only that much information, do you suppose you can identify it? Now identify the other specific thing that I suspect is also in the room. That's the life-as-we-don't-know-it challenge.

Re:Not on Arrakis

[Immerman]

Actually if I remember my Dune correctly water was once plentiful on Arrakis, but was locked away deep underground by the larval sand trout in order to provide a more hospitable environment for their adult form, the sand worms.

Also, if plate tectonics stops that means our planet's core has cooled to the point where it can no longer provide a strong magnetosphere, at which point the solar wind will begin stripping away our atmosphere, boiling away the oceans in the process as the air pressure drops, and leaving erosion to be a process fueled primarily my meteorite impacts. Much as is believed to have happened to Mars some time in the last few tens of millions of years.

Re:Not necessarily water oceans

[Immerman]

Actually, the problem with a gaseous environment is not that the molecules are too far apart - in fact you get a (very roughly) comparable frequency of collisions, and they're at higher energies which make reactions more likely. The problem is that as larger molecules form they tend to precipitate out of solution, and in a gas there is insufficient buoyancy to keep them mobile once they've done so. On Earth life likely evolved within the primordial open-faced sandwich on the bottom of tidal pools, borrowing mobility from the surrounding water and structure from the solid substrate. Get rid of either and things become much more difficult, though there's no reason to believe it would be impossible. Get rid of both (such as in the atmosphere of a gas giant where chemistry becomes radically altered at the enormous pressures around the quasi-solid core) and you're in completely unknown territory.

It's also worth mentioning that gas-versus-liquid has little to do with distance between molecules except at a given pressure, the phase is determined by the nature of the weak intermolecular bonds. The gas deep within a gas giant could be far denser than water, but the immense pressure and temperature maintain it in a gaseous state, smoothly transitioning to liquid as you go deeper. Or perhaps not - high-pressure chemistry is still a very young field and we keep discovering surprising things.

Neil DeGrasse Tyson

[The Evil Atheist]

As Neil Degrasse Tyson notes, the life we do know is primarily made of, in order of proportions - hydrogen, oxygen, carbon, nitrogen, other. Other than helium, the order matches exactly the proportions of "normal" matter in the universe. It's not a stretch to look for life made up of the most common elements in the universe.

Re:Limited Imagination

[drinkypoo]

Of course, almost none of the thousands of other species on Earth look exactly like us,

Exactly? Come back here with those goalposts. Creatures here have eyes above nostrils above mouth for a reason; likewise, they have head above body (at least in some positions) for a reason. The mouth is at one end, the ass at the other. If it were advantageous to have these features somewhere else, they might well. For anything which meets our definition of life, it's reasonable to imagine that they would take on a similar form.