Water World with surface temp of 397K?
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I guess it depends how deep the water is. A pond in the desert would evaporate, but the surrounding sea would cool down as it got deeper. The surface of the water would evaporate, then later precipitate back, given enough mass for gravity to hold on to it. Just a guess; I really don't know.
Ah....1.92 atmospheric pressure.....which, if I remember Boyle's law, would drive the boiling point up, right?
The higher the pressure, the higher the temperature required.
This is also the reason we can have ice worlds that have extremely hot surfaces too. Some places have crazy atmospheric pressure.
That's the point of them, to get the temperature up without all the water evaporating away.
You can also test the thing yourself, if you have a thermometer which goes up to 100° Celsius, a pot and a stove/fire:
near sea level water boils near 100° C (depending on the weather ~ air pressure), up 3.6 kilometers it is 85° C.
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I found a large landable icy planet with a surface temperature of 467k (194 Celsius) and no atmosphere.
It is in the second video at 7:35.
Part 1 and 2 of my current exploration journey.
Part 1 Source: https://youtu.be/RrrKPXlRlV4 Part 2 Source: https://youtu.be/NRni51mF1CM
1) The state change from liquid to gaseous requires energy, the state change back into liquid releases it.
So if you put a lid on your pot the water, the vapour condenses on the lid releasing the energy there and the heat remains in your "pot system" (instead of heating your kitchen air and ceiling).
2) If you increase pressure, you raise the temperature when the state change occurs. So you can reach higher a temperature without losing energy due to a state change at all. (The pressure cooker thing.)
3) Thermal capacity at constant volume is lower than at constant pressure, so you reach higher temperatures with the same energy if you keep the volume constant by pressurizing it. The effect is negligible for liquids though (but very important for gas).
I found a large landable icy planet with a surface temperature of 467k (194 Celsius) and no atmosphere.
It is in the second video at 7:35.
Part 1 and 2 of my current exploration journey.
Part 1 Source: https://youtu.be/RrrKPXlRlV4 Part 2 Source: https://youtu.be/NRni51mF1CMforums.frontier.co.uk
At 2,500 metres water boils at about 90c, on Earth for each 250 meters increase in height water boils at temperature about .5c lower. The lower the pressure the lower the boiling point, I thought this was a well known fact, oh well that's my fault for assuming I suppose. The boiling point of water in a pressure cooker is 121c, or 250f, the increase in pressure is around 15psi, so higher pressure equals higher boiling point of water equals faster cooking of food!
Ammonia is a natural refrigerant. I would think that a 70% ammonia atmosphere would be constantly cooling the lower atmospheric "depths". I don't know exact science behind it, but liquid ammonia is a widely used efficient industrial refrigerant. One would imagine that an "ocean world" of the stuff would be very cold below the "surface".
Well. Back to it.
o7
Well. Back to it.
o7
Refrigerants work a bit differently, and aren't really applicable in this case. They're effective for heat transfer due to having a boiling point (or phase change) in a particular temperature range, depending on the machine or application, and due to having good specific heat values that are well separated between the vapor and liquid forms. (Specific heat is just the amount of energy that can be stored in a given amount of material). It's just a question of how efficiently it can be used to pump heat energy from one place to another. Unfortunately it doesn't inherently cool something just by being present. Ammonia is starting to catch on because it's fairly environmentally friendly and inexpensive.
You're probably thinking of evaporative cooling, but that's not really the right thing here either. Heat energy that is lost from a surface will still be present in the atmosphere.
You're probably thinking of evaporative cooling, but that's not really the right thing here either. Heat energy that is lost from a surface will still be present in the atmosphere.
Even if you had a liquid ocean of the stuff constantly in circulation? It wouldn't matter in dispersing heat?
Any fluid can have convection currents, though I suppose the efficiency will be different for different materials. The thing that makes Ammonia good as a refrigerant are properties that are specific to the machines though-- phase change at a specific temperature, and separated specific heat values for vapor and liquid states, since refrigerators rely on the phase changes as part of their cycle. Convection doesn't do that, as such, but it's similar in that it transports heat via fluid motion. However, most of the loss of heat from something like a planet is in the form of radiation into space, which atmospheres tend to slow by reabsorbing some of the radiation from the planet's surface.
So many posts in this thread, and no-one has yet posted a link or pic of the phase diagram of water. Stealing the one from Wikipedia (again):
1 bar = 1 atmosphere, approximately. I do not know how much detail of the actual real-world water phase diagram has been programmed into the Stellar Forge, but it's usually pretty accurate in verifying the surface conditions of water/ice planets found in ED. The water on the OP's water world is almost boiling, but not quite.
The only exceptions I've noted are those like Deserted-crib3 mentioned, the ones rated as "No Atmosphere". Those are, indeed, law-of-physics-breaking. In the real world, hot ice in a vacuum would sublimate (go straight from solid to gas without turning into a liquid first), and either disappear completely (leaving a water-free surface like the Moon) or create a water vapour atmosphere. I suspect there's some glitch in the Forge where a planet's atmosphere is randomly switched "off", when it lawfully shouldn't. There might be tweaking to this part of the Forge once Odyssey comes out, but I doubt it.
1 bar = 1 atmosphere, approximately. I do not know how much detail of the actual real-world water phase diagram has been programmed into the Stellar Forge, but it's usually pretty accurate in verifying the surface conditions of water/ice planets found in ED. The water on the OP's water world is almost boiling, but not quite.
The only exceptions I've noted are those like Deserted-crib3 mentioned, the ones rated as "No Atmosphere". Those are, indeed, law-of-physics-breaking. In the real world, hot ice in a vacuum would sublimate (go straight from solid to gas without turning into a liquid first), and either disappear completely (leaving a water-free surface like the Moon) or create a water vapour atmosphere. I suspect there's some glitch in the Forge where a planet's atmosphere is randomly switched "off", when it lawfully shouldn't. There might be tweaking to this part of the Forge once Odyssey comes out, but I doubt it.
Was tempted, but thermodynamics usually messes with people's minds too much. Unless you meet that special kind of people, then it still does, but they enjoy that weird sensation
Yes, noted that one mismatching as well. But "switching atmosphere off" doesn't explain. Look at that one:
Let's assume the surface of this planet is ice, and temperature ist correct. And there is some amount of water sublimated and forming an atmosphere, but in a "hidden" atmosphere. For a solid phase to exist, you would need a pressure around 10 GPa @ 575K, let's assume we got surface pressure as well. Gravity decreases further away from the core, so you would inevitably get a liquid phase above the ice. (A rough estimate would be, that layer is 500 km thick to get 10 GPa@2G, if my calc.exe skills didn't fail me...) A possibility to avoid that would be a supercritical fluid, but you get that only above 647K.
Any other ideas, that are not be breaking physics?
Best I can come up with is "a truly strong magnetic field is influencing on the hydrogen bonds"...
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Here's what I mean about "randomly switching atmospheres off".
Suppose the Stellar Forge, operating in its "natural" state, created far too many worlds with atmospheres - leaving relatively few worlds without an atmosphere. So they tweaked it, not by making atmosphere creation less probable, but by adding an extra line to the Forge, deleting atmospheres at random to create a more realistic number of airless worlds. But, only the atmosphere is deleted, the base structure of the world that created the atmosphere in the first place is left unedited. Thus, we get "airless" worlds that break the laws of physics, like airless water worlds, airless ammonia worlds, and airless hot-ice worlds. I believe the earliest versions of ED had airless Earth-likes, too, but that was soon patched.
I don't know this is what happened, but it seems a reasonable conjecture, given the care with which the Stellar Forge otherwise obeys the laws of physics (as seen by the OP's planet, and countless others that obey the water phase diagram).