Magma life

[parallaxicality]

I was wondering, with all this speculation about life existing in Europa's subsurface ocean, what are the chances of some form of life existing in our subsurface ocean? If life can exist in liquid water, why not liquid rock?

[eburacum45]

I considered the idea of a non-organic, lava-dwelling form of lifelike complexity in this speculation here for Orion's Arm;
http://www.orionsarm.com/xenos/Rheolithoids.html
the idea was that geological processes alone might acheive enough of the characteristics of life (like self-replication, energy through-put and responsiveness) to be classified as life despite having no carbon (or silicon) organochemistry.

However, despite supposedly studying geology many decades ago, I have no idea if this wild speculation is plausible.

Since the underground ocean you seem to be referring to is one which is locked up deep in the mantle in hydrous wadsleyite, I don't know if this water would be available to support any kind of life; but it is an interesting prospect.

[parallaxicality]

No, I was being metaphorical. This issue arose when I was having a discussion over on Wikipedia over the claim that Titan is the only world other than Earth with open bodies of liquid on its surface. He argued that gas giants have "oceans" of liquid hydrogen, and no surface, ergo they also have open bodies of liquid.

I noted that there was a tendancy among planetary scientists to call the inner liquid regions of outer planets "oceans" because they were made of liquids other than rock. This is particularly true with Europa, whose inner liquid region is often called an ocean, when really it should be called a mantle. But, I thought, if Europa's mantle could be called an ocean, why not ours? And if it could be an ocean, could it have life?

[SkepticJ]

In the educational book What Does A Martian Look Like?, by Jack Cohen and Ian Stewart, they speculate on a form of life that would live in the mantle of a planet. Most of the life in the book is really weird and hard to describe, so sorry that I don't.

[eburacum45]

It's tricky; a life form cannot be entirely soluble, or it will be both too dilute and too disorganised to be considered an organism. But magma as an 'ocean' is so hot that most solids would be molten, and all organic carbon materials would be denatured and destroyed. So only a few materials (diamond is one) would remain coherent if the magma is not too hot.

Secondly, life-like organisation needs a thermodynamic disequilibrium to exist; according to the excellent National Academy of Sciences report anyway-see this page;
http://books.nap.edu/openbook/030910484X/gifmid/8.gif

In particular the requirement for thermodynamic disequilibrium is so deeply rooted in our understanding of physics and chemistry that it is not disputable as a requirement for life. Other criteria are not absolute.

Are magma oceans in thermodynamic disequilibrium? Something is going on in Earth's mantle, at least, as a massive magnetic field is generated in an active core below the mantle, and above the mantle the continents are moving slowly. But is this disequilibrium enough to support life of some bizarre kind?

Quite possibly, in my opinion- but that doesn't mean it exists.

[Mellow]

In the educational book What Does A Martian Look Like?, by Jack Cohen and Ian Stewart, they speculate on a form of life that would live in the mantle of a planet. Most of the life in the book is really weird and hard to describe, so sorry that I don't.

I also read "Evolving the Alien" by the same chaps, it's a really good read which takes the reader quickly into very different thoughts on self replicating/lifelike systems.

[Argos]

An interesting fiction story on this suject: "The Pressure Within" - A. C. Clarke.

[Doodler]

No, I was being metaphorical. This issue arose when I was having a discussion over on Wikipedia over the claim that Titan is the only world other than Earth with open bodies of liquid on its surface. He argued that gas giants have "oceans" of liquid hydrogen, and no surface, ergo they also have open bodies of liquid.

I noted that there was a tendancy among planetary scientists to call the inner liquid regions of outer planets "oceans" because they were made of liquids other than rock. This is particularly true with Europa, whose inner liquid region is often called an ocean, when really it should be called a mantle. But, I thought, if Europa's mantle could be called an ocean, why not ours? And if it could be an ocean, could it have life?

I believe the call it a mantle mostly because its a liquefied substrate under a primarily solid surface. Oceans, in the traditional sense, are open surface liquid bodies.

In Europa's case, its a mantle, just one who's material content is more analagous to an Earth ocean. Kind of a variation on "well, is it a planet or isn't it?" with locational factors involved.

Shoot...did I just shoot my own danged planet definition in the foot or what?

*limps off bleeding*