Plausibility of this meteor habitat?

[Kiwimaster76]

So in a story I'm writing humanity has found itself on another planet, its larger than Earth but less dense so that the gravity is roughly the same. There is a higher concentration of oxygen on this planet and most of it is pretty habitable. However for reasons that are too long to include say there was a group that decided to live in a meteor crater.

The crater is 21 km across and almost a mile deep, its in the arctic region of the planet and outside of the crater is very inhospitable wasteland, freezing cold, solid rock, basically an island the size of Hawaii's biggest island of barren rock with this crater on it. Inside the crater though is a temperate rainforest (emphasis on temperate, like 50-60 degrees Fahrenheit).

The relative warmth and high rainfall is sustained by numerous geysers fed by natural springs and heated by a central volcano that was made when the impact happened. The people are advanced enough to have some control over this volcano and use it for power and such.

So ignoring logistical problems of getting into a mile deep crater and such, is this a plausible or even possible concept? Could this environment actually exist or are there problems with it that would make it not as hospitable as I've written it? And if there are problems are there any high tech solutions to make it livable? These people have huge amounts of resources and are determined to make it a good place to live.

 

[Janus]

A problem that I see is that volcanoes tend to produce a fair amount of poisonous gases that would build up in the crater. Sulfur Dioxide would also dissolve into the water in the air to produce acid rain.

 

[Nik_2213]

A problem: There seems to be an anti-correlation between big impacts and local volcanism.

Okay, the jury is still out on 'near antipodal fracking' of flood basalts etc from prior eruption. IMHO, one (1) subtle change of Deccan magma mix at approx. time of Chix' impact is not sufficient data. But, yes, interesting...

So, go with a regular volcanic caldera. Hot springs, gas vents, geothermal stuff. Does it have a crater lake ? If so, you must deal with CO2 build-up in the deep water, with potential disaster if layers 'overturn'. As for several lakes in Africa, a 'soda syphon' arrangement may suffice, piped to outside...

Also, I reckon you'd burrow into the caldera walls for shelter, perhaps utilising lava tubes at start. This would allow ventilation to the 'outside', plus 'gas trap' foyers / air-locks.

 

[Kiwimaster76]

So its seeming as if the volcano is the big problem. If it was replaced with just a center peak from the craters formation and instead there was a large stable magma pocket pretty far under it that vented out to the edges of the island would that solve it? That way there would be no gas released directly into the crater and the fracture lines from the impact crater would serve very well for geysers and springs that went down towards the magma pocket to heat water. These people are advanced enough to engineer tunnels and pumps for venting excess magma while letting enough stay to keep the pressure up and the pocket from collapsing and forming a caldera.

As for the acid rain as its in an actic region and if the gas and magma were vented outside of the crater i know there might be an influx of air towards the updraft of air made by the heat from the crater. However would the rain fall before reaching the crater? The air outside is cold which would let the water vapor condense faster and the island is pretty big, about 150 km across. So would the acid rain fall mostly on the wasteland outside the crater? The mixing of warm and cold air tends to make storms i know at least and so there would likely be storms around where the magma met the ocean constantly maybe dumping the acid rain immediately? Leaving the humid air rising from the crater and the cold air from outside making it rain and storm a lot above the crater but with mostly clean water.

 

[Rive]

As I see it the main problem is not the volcano, but the insufficient insulation what a crater just a mile deep would provide. I would just make it 4-5 mile deep, with the air thin on the outside (matching with the air pressure on Earth at 4-5 mile high).

But if you need the outside still habitable, despite the already inhospitable environment, then of course this won't work...

 

[Kiwimaster76]

I see, well the atmosphere on the planet is actually supposed to be a little bit denser than Earth (A major part of the story is based on large hovercraft). I would consider making it deeper anyway but the deepest craters on the moon are at max 3.7 miles (6 km) and this is an active planet and the crater is in basalt, not in loose dirt on the moon and craters on Earth rarely stay over half a mile deep from what I've researched. So a mile is pushing it anyway, deeper is not really scientifically possible (from my limited research, i may be wrong) unless i want to step the size up to more than a few hundred km. At which point I think it might be impossible to insulate like that unless i do drop the atmosphere to nothing.

And yes the rest of the world needs to be openly populated with vegetation and life so that's not quite possible. The rest of the world is basically a larger Earth with some native life and a lot of Earth life that was engineered to thrive there (humans have been on the planet about 300 years, about 2 billion at this point so it's been modified to their liking a lot), a sightly higher oxygen content and lots of rain. Its only that this region is arctic and desolate that its mostly uninhabitable.

It is a Sci-Fi/ Fantasy type story so i suppose i could use a Fantasy reason for this to work but that's practically saying "it does cause i say so" and that's not really a good reason. I like scientific explanations for most stuff, even the fantasy stuff is mostly-science based.

 

[stefan r]

Iceland is nice. They have lots of geothermal springs and volcanoes.

 

[Kiwimaster76]

Iceland is nice. They have lots of geothermal springs and volcanoes.

So is Hawaii, its literally one big volcano and its debris. Only thing is they have winds off the ocean that blow away the volcanic gasses. If it's a crater it won't get those winds. That is a good point though, there are some real world examples I should probably take a closer look at.

 

[essenmein]

How do you hand wave away that you have a planet made of basically the same stuff as Earth (water, rocks etc), is bigger yet some how less dense? If its less dense does that not mean its not made of the same stuff?

 

[Kiwimaster76]

I don't recall stating exactly what the planet is made of except for mentioning the island is basalt. But the planet is less dense as it it's makeup is different. Not all rocks weigh the same and quite frankly a large part of this planet is water and to a depth that makes Earth's oceans look like a puddle. Earths density is 5.51 g/cm^3, the density of water is 1 g/cm^3. Most rocks have a density of between 2.2 g/cm^3 and 3 g/cm^3. Part of Earths big mass increase comes from its core which is solid iron (7.86 g/cm^3). This planet while larger is less dense as it has far more water, thicker crust (rock) and a similarly sized core, the planet is not as rich in iron as Earth but does have an abundance of other metals that tend to be lighter such as aluminum and titanium. Yes the volume is larger and yes it has more mass but density is mass/volume and that fraction is lower here.

So technically yes and no, its made of the same stuff (for the most part but that's story stuff) just different proportions of it.

 

[essenmein]

I don't recall stating exactly what the planet is made of except for mentioning the island is basalt. But the planet is less dense as it it's makeup is different. Not all rocks weigh the same and quite frankly a large part of this planet is water and to a depth that makes Earth's oceans look like a puddle. Earths density is 5.51 g/cm^3, the density of water is 1 g/cm^3. Most rocks have a density of between 2.2 g/cm^3 and 3 g/cm^3. Part of Earths big mass increase comes from its core which is solid iron (7.86 g/cm^3). This planet while larger is less dense as it has far more water, thicker crust (rock) and a similarly sized core, the planet is not as rich in iron as Earth but does have an abundance of other metals that tend to be lighter such as aluminum and titanium. Yes the volume is larger and yes it has more mass but density is mass/volume and that fraction is lower here.

So technically yes and no, its made of the same stuff (for the most part but that's story stuff) just different proportions of it.

Heh, I went and looked at what Earth is made of as well :D

Re stating what planet is made of, I just figured of you have water and rock in one place, then most likely that is everywhere, not like you'd see a little spot of water and a rock island and the rest is a gas giant or something.

Then I think the iron core is actually important to allowing any kind of life to exist because the iron core provides the magnetosphere and that protects against the barrage of charged particles that would strip away any atmosphere or water. So if its smaller and the planet bigger you may want to contemplate if the resulting mag field is strong enough to protect this planet and allow it to even have any kind of atmosphere.

 

[Kiwimaster76]

Ohh, I see. No the entire planet is like Earth in materials. Its just things like the far deeper oceans and thicker crust that make it lighter.

The core isn't smaller than Earth's, it's slightly bigger but not by much and not proportionally to the planets increased size. The magnetic field is made stronger by the core rotating faster than Earth's core. ( I'm not entirely sure of the effects of this so if you know that would be great, my current guess is faster tectonics and stronger volcanic activity but this isn't my field of expertise so i have no real idea) The atmosphere should be able to exist, when I say less gravity I mean about 9/10 that of Earth's, only slightly less and Venus has a far denser atmosphere than ours with that much gravity.

 

[Klystron]

The original meteor strike that created the crater could have hit high on a tall mountain. Once you introduce tall mountains, perhaps the planet has a mountain tall enough to reach the 'exo-atmosphere' analogous to Mons Olympus (if Mars had a thick atmosphere). The advanced mountain-crater people might want to develop the taller mount for a space port.

Just for fun the crater dwellers could be adapted to lower air pressure or colder temperatures analogous to Tibetan people. On the fantasy side, of course the high mountain people are more spiritual than the sea-level hoi polloi.

 

[Kiwimaster76]

That is actually a really good idea! The mountain would have to be unbelievably massive even if I shrunk the crater but if it was a tall, wide volcanic mountain like Mons Olympus that would actually work well and be a good massive island. This would also lend well to how the crater is supposed to be very defendable as the main method of transport are the hovercraft and that high up they won't work very well.
The meteor impact would have probably collapsed most of the magma pocket under the volcano, making it extinct, but maybe there's a little pocket left that can heat the water in the geysers and springs. The water getting there is an interesting problem but with what vents for gas and what magma there is being forced though cracks in the bottom the toxic gasses wouldn't be able to return to the crater in any way at least. Maybe the water for the vapor blanket actually enters at the bottom and as its heated works its way up through all the cracks from the impact to the top of the mountain.

The crater is more a headquarters for a group that's active across the planet than a separate people, people from all the factions would be there and while there would be a city and most of the peoples homes would be there, the crater dwellers would likely be spending lots of time in all sorts of environments so I'm not sure that they would adapt to the extent of the Tibetan people. Probably to a personal level of just getting used to it instead of genetically.
The spiritual idea is interesting, it's likely there would be more spiritual people there both as a result of the natural beauty and as a result of the groups work, (they help and protect people without asking for anything, both with recovery aid from natural disaster and military aid if some of the wildlife (or other humans) get too aggressive. That is the short answer to what they do.) I will have to look further into that and see what I come up with.

Thanks Klystron! That was actually a really helpful idea, in more ways than I expected!

 

[Klystron]

Glad to help. To me the novel is a sublime art form that announced the information age and should survive. Novels describe the human experience as even the most abstruse science fiction characters spring from a human mind, or our creations. Your meteor crater premise, though scientifically, plausible needs tension to develop characters and plot.

Consider criteria for joining the high mountain society. Oldest and wisest? Then the 'young turks' constantly scheme and plot to rise in status. Tallest and most visually pleasing? Intelligence and education? Celebrity and name recognition? All create tension and give the less powerful incentive to rise in their society. Perhaps religions on this world are replaced with height obsessions (giving the author license to compare Earth theologies with less offense).

Conversely, children enjoy playing 'crater games', digging into the clean dirt like inverted sand castles. Teens race their hover craft over the soft sand. Kids wear the colors of their favorite sand racers. Adults ride sedate but powerful lift engines. See this PF thread among several others https://www.physicsforums.com/threads/lift-engine.951255/ .
https://www.physicsforums.com/threads/hovercraft-lift.963564/#post-6114217

 

[rekoj]

The habitat which would be artificially made would definitely need to be evolved in order to say teraform a planet to make it all around habitable. >our concept of volcano is very plausible to me. The society in question however would be something completely different from the earthlings. Maybe a suggestion of story of this new society that develops their minds to such states as to be able to defy phsical laws of reality.