Alien Life in Buried Oceans

Antius · 2017-10-26 12:02:28

Interesting solution to the Fermi paradox presented by Alan Stern:
https://www.space.com/38577-fermi-parad … ceans.html

In short, aside from Earth's surface – all of the potentially habitable environments in our solar system are oceanic and buried under thick shells of ice. These environments are more stable habitats than our planetary surface and hence, there is more time for intelligent life to evolve without disruption. The downside is that any life evolving at such depths would have a very difficult time making it to the surface and becoming space faring.

There is another problem that Stern has not picked up on. The average solar flux at Earth's surface is >100W/m2. The thermal flux exiting the core of a world like Enceladus and entering a slushy mantle is measured in mW/m2. So there is actually remarkably little energy to support a food chain, even if such an environment appears habitable in terms of liquid water and nutrients. This would tend to limit the diversity and complexity of life emerging in buried ocean habitats. It is likely to remain simple, because complex life tends to sit higher up the food chain. Without the ability to harness fire, they would also be stuck in a technological cul-de-sac, as they would be unable to refine metals.

This interesting scenario brings me back to a terraforming concept that we toyed with on this board a couple of years back. The hydrostatic pressure at the centre of a ball of water some 54km in diameter would be exactly 1bar.
http://www.asterism.org/tutorials/tut38 … iation.pdf

What is more, at such low gravity, convection would be a very slow means of removing heat. Heat would need to conduct through the water and ice – which would have thermal conductivity in the 0.5-1W/m.K range. Future human colonists could seek out icy Kuiper belt objects and use the waste heat from nuclear power sources to melt large internal cavities within these bodies. At the centre of gravity, huge inflatable structures a kilometre or more in diameter could be home to low-G ecosystems, with humans housed in rotating buildings. This would be technically quite easy to accomplish, as the same nuclear heat source can be used to melt its way down to the core.

As the cavity gradually expands, silicates trapped in the melting ice will gradually sink to the centre, where they can be extracted and used for construction.

There are many millions of Kuiper belt and Oort cloud objects in this size range and they extend half-way to the nearest star. The far future of humanity in space may end up being a slow migration between the Oort clouds of the galaxy, slowly hopping from one terraformed comet to the next. If we successfully develop deuterium fusion, then these bodies could be semi-permanent homes, potentially lasting for many millions of years. If not, then the power source must be whatever uranium and thorium can be extracted from the silicates. This would limit habitability to thousands of years and the settlers would tend to move on relatively quickly.

Last edited by Antius (2017-10-26 12:08:09)

Void · 2018-01-03 13:01:34

You always seemed a polite and tolerant and highly intelligent person. So...I will make a small attempt to amuse you on this lonely thread.

I don't think there is a certainty about this yet, but....
https://newsroom.unsw.edu.au/news/scien … er’-energy

I read about it recently. Hydrogen and Boron fused. It...
-Requires much higher temperatures that it is proposed to obtain with lasers.
-Does not emit Neutrons? Not radioactive.
-Should produce electric current from particle streams, not with boiling fluid and turbines.

Boron is in short supply though, but who knows maybe there is a lot somewhere. There certainly is a lot of Hydrogen.

As for your commentary about life in "Ice Shell" covered oceans, I mostly agree.

Any exception would require a method to access the surface, and likely also needed is free Oxygen. What else might help would be exposed rock with volcano's, and hot springs.

Unlike Europa, where radiation is thought to form Oxidants, I would have to believe that the object would need a substantial atmosphere up to 10 bar?. So, how free Oxygen would exist is a real problem.

Most likely it would require https://en.wikipedia.org/wiki/Polynya
And it is also possible that some photo organisms could live in the ice.
Another path would be Abiotic, and would require a world where Hydrogen could rather easily escape, but Oxygen would be retained for the most part. Then, if U.V. could come into contact with the Ice and water, and vapors of water, an Oxygen atmosphere might evolve without photosynthesis. It is thought that Mars had such an era.

Another fuel source beyond what I think you accounted for (Sorry if I am wrong about that), would be the rusting of rocks. "Rusting" of certain rocks:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4523005/
Producing H2 and CH4. I believe the process produces heat as well. There can be warm springs without geothermal heat.

On Earth some fish are at least partially warm blooded, so perhaps given the opportunity and limbs, they would seek to escape predators in order to breed, like Penguins. And like penguins they might develop feathers or fur to retain heat.

Two methods to escape predators would be to rise though a natural opening in the ice, or to burrow into the ice above the water line. In the case of burrowing, perhaps they would form a collective community like ants, and eventually burrow all the way to the surface.

The possibility of building shelter and fire on the surface would exist. The Inuit do it. However, an exposed volcano would likely be very helpful. Perhaps they would learn to harness geothermal energy. And then Wind and Solar energy. Winds would be fierce on a tidal locked world, but that's lots of energy. Solar concentrating mirrors would be intuitive, as a simple curved snow block wall near the terminator pointing it's concave at the solar source would provide a source of heat that would be rather constant except for obstruction by clouds and white outs.

A compromise between Io and Europa, but of a larger size would be possible. Of course I am thinking of tidal heating being significant. Just because Jupiter has a deadly radiation belt does not guarantee that the Moon/Planet under consideration would be exposed excessively to one.

So, a gas giant hosting a sizable moon with tidal heating might work out. If it were perhaps the size of Mars, and of a character between that of Io and Europa.

Or a Trappist - 1 type planet.
http://www.ibtimes.com/exoplanets-trapp … fe-2635766

We hear lots of stories about why Red Dwarf planets would not have atmospheres, but they typically leave me wondering why our Venus has an atmosphere. The reason is that it has a induced magnetic field. It does loose atmosphere, but much of that is Oxygen which is levitated upwards by an electric field which apparently exists because of the dryness of the upper atmosphere (So, I interpret what I have read).

Mars looses atmosphere apparently because is small and it has a partial geomagnetic field which interacts with an induced magnetic field. Earth has a complete geomagnetic field and is protected. Venus has an induced magnetic field and is protected (It actually has a very weak geomagnetic field at the surface, but it is too weak to cause trouble).

I know you were mostly thinking of worlds with thick ice shells such as our Europa and Enceladus. However there is likely a continuum of water/Ice worlds where the thickness of the shell goes from no ice, to ice all the way down to the surface.

A thick atmosphere, strong hot currents, especially from tidal heating could open up holes by melting, and by pushing the ice around. Tidal locked worlds would have very strong winds.

And I have been proposing this for some time here. Now someone says it also. Good!
https://arstechnica.com/science/2017/10 … agma-soup/

Magnetic Induction heating of a planet or moon by solar wind. I believe it also happens in this solar system but at perhaps 1/1000th the energy. Still, I believe that volcanism may be driven in part by the solar winds magnetic induction. So, here is another possible source of heating of a planet or moon outside of the habitable zone.

As I said I intended to amuse you. Hopefully not annoy you.

Last edited by Void (2018-01-03 14:14:31)

lindahughesons · 2018-04-12 16:22:30

Hm.. so much interesting ideas! Thanks for that information on such topic!

louis · 2018-04-12 16:43:02

I've always felt that the colour change ability of species like squid in the deep would potentially provide a much more effective communication system than our sound based vocalisation system. For instance, a highly evolved squid could when say discussing a complex concept keep up a list of bullet points on its surface while going through point by point...and at that same time indicate their emotional state, their willingness to continue the discussion (a sort of hour glass).

Void · 2018-04-13 11:30:53

Sorry about my previous post, I must have been confused. For that I will be brief.

I suggest that Mars, and some of the Moons of Saturn, Uranus, and Titan may have chances of the ultimate survivor that I could currently be aware of. That is as in South African gold mines, life that exists from chemicals that result from radioactive decay. Hydrogen for instance.

https://arstechnica.com/science/2008/10 … ty-of-one/
https://www.princeton.edu/news/2006/10/ … d-thriving

So, a method exists without sunlight or even an "Underground ocean".

I have relatively lately considered Mars, the moons of Saturn, Uranus, Neptune, and dwarf planets/objects beyond.

Even without true oceans, could we consider the possibility that rocks fractured and with pores under an ice shell might become warm enough at some level where moisture and thermal and PH and salt conditions allow life?

Then, the basic mode of life, stripped down to bare ability to exist. Granted, I allow for precursor life, and the God as well at the same time, but I don't want to get into that here at this time.

The notion then is that there may be multiple places where life may hang on. Where did it come from? Panspermia? That being solar, interstellar, or even galactic?

But then what is our moral response to it's possible existence? Is the human race so not valuable that we hold it back, or allow others to hold it back?

Lots of questions.

Again very sorry about the lack of ability demonstrated by me in post #2.