We Need To Talk About Rocky Ice Worlds

While out exploring, I have intermittently encountered a very odd planet type.

6AC0Grm.jpg


It looks like a High Metal Content - or even a Metal Rich - world, although in all honesty they look more like they're made entirely of chocolate.

Mh1s7Rb.jpg


But no. They're called Rocky Ice worlds. They share a highly unusual feature. See if you can see what it is.

Qbg2UaX.png


Got it? If not, here's some more clues.

HRi445I.png


H2hPQhT.png


etYXFmo.png


The description doesn't appear to match the actual planet, putting it mildly. What I assume is happening is that the entire ice content of the planet is being treated as atmosphere, even though at that pressure it would be Ice X and therefore a solid. This rather implies that when we can actually land on these worlds we won't land on top of the ice sheet, but will rather plunge through thousands of atmospheres-worth of sublimating ice until we're crushed like tin cans.

This therefore needs fixing before these planets become landable. I suggest, while doing so, that they be renamed Chocolate Worlds and the surface ice be replaced with a thousand layers of gooey caramel.
 
It does say "often creating", OK your example doesn't match, but most, I think, do.
.
edit - just found one 800 atmospheres. Not as bad as yours, but not thin either.
edit - two more, 6 atm and 0.01 atm. At least the last one fitted the bill.
 
Last edited:
Atmosphere type is 100% water which has probably got something to do with it. Just think of the huge pressure of all that water on the surface.
 
Last edited:
I remember there was a 7th Draconis in Dan's Simmons Hyperion, that atmosphere got frozen after terraforming machines stop working after the Fall.
 
You can't.
Remember that we measure atmospheric pressure at the surface, not at the edge of space. I think it might be feasible, given the right situation. remember Venus has a lower gravity at the surface than us, but much higher pressure.

The atmosphere would obviously need to be a heavy gas - so as not to dissipate - and you'd need a lot of it. Essentially it'd be more of a gas giant that had a rocky core.

Possibly.
 
Atmosphere type is 100% water which has probably got something to do with it. Just think of the huge pressure of all that water on the surface.

Precisely that. The high atmospheric pressure results in a very high albedo, thus the metallic sheen.
 
Remember that we measure atmospheric pressure at the surface, not at the edge of space. I think it might be feasible, given the right situation. remember Venus has a lower gravity at the surface than us, but much higher pressure.

The atmosphere would obviously need to be a heavy gas - so as not to dissipate - and you'd need a lot of it. Essentially it'd be more of a gas giant that had a rocky core.

Possibly.

Pressure on Venus is 90atm. It's a long way to 30,000!
 
Notice the temperature of that planet, 1,900K and a water atmosphere. That's why the pressure is so high. And the pressure is why there's ice at that temperature.
 
Notice the temperature of that planet, 1,900K and a water atmosphere. That's why the pressure is so high. And the pressure is why there's ice at that temperature.

Yes but pressure does not form because magic. Gravity causes pressure. And at 0.36G how much water you need to get that pressure? Not to say it would disperse into space long before that...
 
The gravity is measured at the solid surface, but what if the bulk of the mass was in the atmosphere? Not too unlikely at that pressure. It may explain it. I think the planet is very close to being a water giant anyway.
 
Intuitively, yes, this does appear to nearly be a water giant with an enormous core. Unfortunately the way it's visually represented in game is by rendering what should be a very chaotic atmosphere as invisible, leaving only the chocolate underneath.
 
Yes but pressure does not form because magic. Gravity causes pressure. And at 0.36G how much water you need to get that pressure? Not to say it would disperse into space long before that...

Not really. Or rather: Not entirely. Pressure is the result of gravity, combined with the mass of the atmospheric column above you. If you have more 'stuff' above you in the same gravity, pressure is increased.

By way of example, water pressure increases by one Atmosphere for every 10m of depth.
And remember that Venus has 90 times our pressure, but slightly less gravity.

So if you stand on a small body, with a very thick atmosphere above you, pressure would be enormous.
And gas doesn't need to be light: Make it colder, it gets heavier. Use a heavy gas - hydrocarbons maybe - and it's heavier still, and less likely to dissipate.

Sure: The planet is insanely extreme, but I don't think impossible.
The rendering though doesn't seem to make enormous sense. Unless the atmosphere is brown and looks like rock!
 
Not really. Or rather: Not entirely. Pressure is the result of gravity, combined with the mass of the atmospheric column above you. If you have more 'stuff' above you in the same gravity, pressure is increased.

By way of example, water pressure increases by one Atmosphere for every 10m of depth.
And remember that Venus has 90 times our pressure, but slightly less gravity.

So if you stand on a small body, with a very thick atmosphere above you, pressure would be enormous.
And gas doesn't need to be light: Make it colder, it gets heavier. Use a heavy gas - hydrocarbons maybe - and it's heavier still, and less likely to dissipate.

Sure: The planet is insanely extreme, but I don't think impossible.
The rendering though doesn't seem to make enormous sense. Unless the atmosphere is brown and looks like rock!

Ok I ran some numbers... to get 30,000atm at 0.36G, you need about 950km of water. On a planet the size of Mars, that seems rather unlikely...
 
Back
Top Bottom