How salty is Laythe?

[fenderzilla]

Since laythe is so far away from the sun, it gets really cold - as low as -40 celsius! this should mean that all the water on it is ice, but it's clearly liquid water. since saltwater has a lower melting point that freshwater, i've concluded that Laythe's oceans are very salty. but just how salty? what would be the salt/water ratio in those oceans to mean that it wouldn't freeze?

[That guy who builds stuff]

It's not salt it's fuel from all the probes I've crashed into it.

[stupid_chris]

" Clearly water" is a false assumption, we have literally no idea what it could be. And not only salt makes water have a lower solidification point, the best candidate, if it really is water, is ammonia IIRC.

[Johnno]

Since laythe is so far away from the sun, it gets really cold - as low as -40 celsius! this should mean that all the water on it is ice, but it's clearly liquid water. since saltwater has a lower melting point that freshwater, i've concluded that Laythe's oceans are very salty. but just how salty? what would be the salt/water ratio in those oceans to mean that it wouldn't freeze?

Water would freeze at −21.1 °C (−6.0 °F) if it was saturated with salt. I'd say Laythe clearly has a liquid on its surface, but I wouldn't say it's clearly water.

[fenderzilla]

It just said saltwater on the wiki, so I believed it. i guess you guys are right.

[stupid_chris]

The wiki is fanmade.

[fenderzilla]

I guess if it is ammonia and water, what would be the ratio of that?

[nyrath]

" Clearly water" is a false assumption, we have literally no idea what it could be. And not only salt makes water have a lower solidification point, the best candidate, if it really is water, is ammonia IIRC.

Yes, I'm with you, ammonia. -40 celsius is far too hot for liquid methane.

I guess if it is ammonia and water, what would be the ratio of that?

Probably pure ammonia with no water.

[stupid_chris]

I think ammonium hydroxide (or ammonia solutions basically) solutions could also have a freezing point below or at 40celcius, which would also allow forms of water based extremophiles in the water. Although pure ammonia freezes at -77celcius, which is plausible but leads me to wonder about the polar caps on Laythe. Must say the temperature model is not accurate yet though.

[stupid_chris]

According to the charts found here, a solution of 22% of weight ratio of ammonia in water would have a freezing point of 43,5Celcius.

[JupiterII]

Wouldn't Laythe be heated from the radiation and tidal forces from Jool? It also has an atmosphere to trap heat. Just because it's far from the sun doesn't necessarily mean it's really cold.

[LaydeeDem]

It's already been stated by Nova that Laythe's oceans are a mix of water and ammonia.

[stupid_chris]

Wouldn't Laythe be heated from the radiation and tidal forces from Jool? It also has an atmosphere to trap heat. Just because it's far from the sun doesn't necessarily mean it's really cold.

It's still cold, I don't know if you expect this to be a tropical paradise, but it isn't. The radiation belt doesn't heat the planet up, tidal forces heat up, but that affects mostly the core of the planet and sure doesn't provide enough heat to have reasonable temperatures, and lastly, it's atmosphere has a density of 0,8 atm, not enough to capture a great amount of heat from the star, at that distance it receives at most 10% the light Kerbin does, so really, Laythe is cold. Stick a stock thermometer and go on Laythe, you'll see that it's cold even to the game.

We'll properly see some differences when more realistic atmospheric and temperature models are implemented, but it won't really heat up if you want my opinion.

[Benie]

if it really is water, is ammonia IIRC.

Whelp, there goes my floating Laythe base... I rather not be swimming in ammonia, thank you very much.

[stupid_chris]

Yeah, ammonium hydroxide is rather hurtful, but I think the Kerbals are usually happy in environments that would normally not be a happy place to be, i.e. reentering the atmosphere at 2km/s, Only a few thousand of kilometers from a star on an arid planet, under 5atm of pressure near seas of radioactive elements, etc

[fenderzilla]

I doubt that the oceans are pure ammonia because they're blue.

[Holo]

Everyone, Laythe has a temperature of 6 celsius. Even check in game.

[fenderzilla]

Wouldn't Laythe be heated from the radiation and tidal forces from Jool? It also has an atmosphere to trap heat. Just because it's far from the sun doesn't necessarily mean it's really cold.

Everyone, Laythe has a temperature of 6 celsius. Even check in game.

like every planet or moon, laythe isn't all one temperature everywhere. the highest temperatures on laythe's surface can reach 6 celsius, and the lowest are -40.

[geb]

... at that distance it receives at most 10% the light Kerbin does, so really, Laythe is cold ...

Solar panels in game don't follow the inverse square law, so we shouldn't assume that planet illumination works that way.

The star in the Kerbin system emits target-seeking photons.

[stupid_chris]

Solar panels in game don't follow the inverse square law, so we shouldn't assume that planet illumination works that way.

The star in the Kerbin system emits target-seeking photons.

I did not assume the illumination that way, I'm aware of this, else, we should assume Laythe receives 50% of the light Kerbin does because panels who produce 2U/sec produce 1U/sec there. My estimation was off the distance from the star. Jupiter receives roughly 4% the light Earth does, 10% and less is not far from a good estimation.

And fenderzilla, the colour is totally irrelevant. Water is colourless, the colour you see it at depends of what's in it mostly, don't forget that some seas are turquoise. Chemistry is tricky, and you can't identify a compound only by it's colour and by the physical state in which it is.

Anyway, I have no clue what colour seas of ammonia would look like and I have no idea why they couldn't be blue. It might still be another compound dissolved in the water.

[Brotoro]

Laythe receives 3.9% the illumination that Kerbin receives.

But the fact that it has a quite thick atmosphere (with 80% the surface pressure of Kerbin) can mean it has a substantial greenhouse effect, especially if it contains a sizable fraction of carbon dioxide. And this greenhouse effect will help trap its heat no matter what the source of that heat is (be it energy from the sun or energy released from tidal friction within, working its way out). Either way the heat gets radiated from the surface as infrared, and the greenhouse effect makes it harder for the heat to escape.

Because of the small distance scale of the Joolian system, tidal forces are much greater for Laythe than they are for the Jovian moons in our solar system. We should not be surprised if Laythe is warm...we should be surprised if it is cold. And the argument that this energy is released in the interior of Laythe does not hold water...it still has to work its way out and be radiated into space to cool Laythe...it can't just disappear inside.

The observed fact that Laythe has polar caps tells us that the energy it receives from Kerbol is enough to push much of its surface above the freezing temperature of the liquid in the oceans (since the relative lack of heat from the sun at high latitudes is why the poles are colder than the equator). The simplest explanation for the oceans is still that they are mainly water (albeit with some additional mix of salts and/or ammonia).

[fenderzilla]

I did not assume the illumination that way, I'm aware of this, else, we should assume Laythe receives 50% of the light Kerbin does because panels who produce 2U/sec produce 1U/sec there. My estimation was off the distance from the star. Jupiter receives roughly 4% the light Earth does, 10% and less is not far from a good estimation.

And fenderzilla, the colour is totally irrelevant. Water is colourless, the colour you see it at depends of what's in it mostly, don't forget that some seas are turquoise. Chemistry is tricky, and you can't identify a compound only by it's colour and by the physical state in which it is.

Anyway, I have no clue what colour seas of ammonia would look like and I have no idea why they couldn't be blue. It might still be another compound dissolved in the water.

Since laythe has a blue sky, the oceans could really be any liquid that reflects. our saltwater seas are only blue because they reflect the sky.

[stupid_chris]

Since laythe has a blue sky, the oceans could really be any liquid that reflects. our saltwater seas are only blue because they reflect the sky.

I guess then the Caribbean is turquoise because the sky is turquoise there, and that my local pond is brown because of the sky in the region too. Sky has little effect on the colour of your water compared to what's in it.

[Guest]

Very salty.

[Aqua667]

If Laythe was covered with ammonia, it would be covered in cleaning chemicals! Liquid ammonia is clear, so there's probably something else in the oceans, maybe dissolved cobalt or copper?