[Bug] Planet Surface Temps Hot as Stars - Breaks Immersion for Explorers

[CMDR Galilean]

o7, Commanders!

While exploring S171 43, I came across a few planets with reported surface temperature over 10,000K, which is obviously a procedural generation glitch. Elite Dangerous prides itself on being a realistic space sim. But stuff like this shatters immersion-- especially for explorers who thrive on authenticity. Planets shouldn't and can't be this hot, not even near a class O star.
Bug report was submitted: https://issues.frontierstore.net/issue-detail/75942, but it seems it requires 10 confirmations before it's even considered for a closer look. If you've seen similar planets, or want to help preserve the sim integrity of the galaxy, please give it a bump. Let's cap planet temps to something physically plausible, and keep the galaxy grounded in science.

Fly safe!

 

[Neilski]

o7, Commanders!

While exploring S171 43, I came across a few planets with reported surface temperature over 10,000K, which is obviously a procedural generation glitch. Elite Dangerous prides itself on being a realistic space sim. But stuff like this shatters immersion-- especially for explorers who thrive on authenticity. Planets shouldn't and can't be this hot, not even near a class O star.
Bug report was submitted: https://issues.frontierstore.net/issue-detail/75942, but it seems it requires 10 confirmations before it's even considered for a closer look. If you've seen similar planets, or want to help preserve the sim integrity of the galaxy, please give it a bump. Let's cap planet temps to something physically plausible, and keep the galaxy grounded in science.

Fly safe!

Well, it may very well be a glitch but it's not instantly and unambiguously unphysical, to me at least. It's an interesting question though. (NB: I haven't considered this stuff in depth so I may be talking nonsense in some of what follows! )

Firstly, I'm wondering how hot you'd be prepared to accept, both in general and for this particular planet/star combo? (Googling a bit suggests that the hottest known surface temperature for an exoplanet is currently a bit over 4 kK, so already crazy hot.)

For S171 43, Spansh says the host star has a temperature of almost 87 kK, which does seem too high for a class O star but isn't impossibly high for any star.
And with a host star that hot, it's not instantly obvious to me that a planet couldn't possibly reach 10 kK. (All the more credible if some kind of internal heat generation were invoked.)

There's a weird anomaly, however: your report and screenshot on the issue tracker say that A 7 A is extremely hot (the screenshot says 6 - 12 kK), but Spansh and Inara both say that the surface temperature of that body (they call it A 7 a, but the radius and mass both match) is a mere 1.4 kK - still pretty darn hot tbf; almost as hot as the class L star it orbits.
No idea what has caused this mismatch... Some kind of data display glitch in game? Or a data-upload glitch to EDDN/Inara?

If we instead consider A 6, which Spansh and Inara list as one of the crazy hot planets in that system, and thus fits your general complaint: Spansh says it has a surface temperature of just over 10 kK, and a surface pressure of over 35 M atm.
I have no clue (maybe some data exists though? ) about the spectral characteristics of an atmosphere that dense, made of "Hot thick Silicate vapour", but just maybe it could act as a greenhouse gas, letting in the deep-UV light from the star but absorbing the nearer-UV light from the surface...? If that were true (and yeah OK that's a stretch!), then maybe it's not all a bunch of unphysical nonsense...

 

[Neilski]

Update:
Following up on this interesting question, I just found a useful Reddit post (https://astronomy.stackexchange.com/questions/20715/is-there-a-maximum-temperature-a-planet-can-have) which linked to an even more useful web page (https://www.dangermouse.net/gurps/science/temps.html).
The latter page has a simple formula for the surface temperature of a planet.

tl;dr: plugging in the (very very) hot star's temperature and radius, along with the planet's orbital distance, along with some possibly-credible guesses for its albedo and atmospheric absorption, that formula is predicting around 10 kK for A 6. (And amazingly, that's without even invoking any greenhouse effects.)

So basically if there's a dodginess to this system, it's seeming like it's probably the star being hotter than a class O is meant to be, rather than the planet being unphysically hot.

 

[CMDR Galilean]

Hi Neilski, and thanks for your extensive input! Let me try and elaborate a bit more on what the issue here is.

Firstly, I'm wondering how hot you'd be prepared to accept, both in general and for this particular planet/star combo? (Googling a bit suggests that the hottest known surface temperature for an exoplanet is currently a bit over 4 kK, so already crazy hot.)

You're probably referring to planet KELT-9b which is literally burning away. A hypothetical one at 10,000K would be melting, vaporizing and disintegrating until it's gone entirely. It would be unlandable, unexplorable with SRV, and you definitely couldn't walk on its surface to collect anemone samples. My suggested temperature cap at ~2500K is based on the approximate point at which a metal-rich planet of this type would turn into a pot of molten lava, with a surface too unstable for landing and exploring. I'm not too fussy about the exact number that ultimately gets picked, as long as it's more realistic.

There's a weird anomaly, however: your report and screenshot on the issue tracker say that A 7 A is extremely hot (the screenshot says 6 - 12 kK), but Spansh and Inara both say that the surface temperature of that body (they call it A 7 a, but the radius and mass both match) is a mere 1.4 kK - still pretty darn hot tbf; almost as hot as the class L star it orbits.
No idea what has caused this mismatch... Some kind of data display glitch in game? Or a data-upload glitch to EDDN/Inara?

Good catch! This makes me believe that the bug in question was introduced more recently, perhaps with the Odyssey expansion.

So basically if there's a dodginess to this system, it's seeming like it's probably the star being hotter than a class O is meant to be, rather than the planet being unphysically hot.

It's entirely possible that the bug originates with the star temperatures, and the resulting domino effect is causing such hot planets as well.

 

[CMDR Yates]

I agree, it seems like these planets should either be capped at a surface temperature that allows them to be plausibly solid, even it means fudging the mathematics that says otherwise, or in an ideal world, rendered as the brilliant, blowtorched objects of death they truly would be at those temperatures, trailed in their orbits by comet-like streamers of luminous, superheated material boiled off their blazing "surfaces".

I suppose making them unlandable and rendering them as lava-sea worlds (assets already in the game) would be fair compromise.

 

[STRONTIUM DOG]

o7, Commanders!

While exploring S171 43, I came across a few planets with reported surface temperature over 10,000K,

well as long as no boney m records start playing ones "cheez" should remain unslid on its proverbial block

 

[Kira Goto]

I'm inclined to think this is a stellar forge quirk because some fully procedural generation systems have bodies like this as well. Usually, they have a totally ridiculous atmospheric pressure number. Which, to no surprise (or at least not mine) this one does. Looking at body A6 as listed on inara, it has a whopping 35 million atmospheric pressure, mostly composed of vaporized silicates. In other words, the surface burned up enough that the atmosphere is the planet's own material.

Is it particularly realistic? Possibly not, but it seems to attempt creating a semblance thereof. I guessed when seeing these cases that there is a strange equilibrium due to the obscene pressure where the surface is sort of but not really solid under the heat. At least until some of that atmosphere is blown away. Of course this would also eventually result in there being no planet any more, but I'm not sure if it would happen on the time scales which can be observed in a single human lifespan. And likely is not part of the simulation.

 

[Neilski]

You're probably referring to planet KELT-9b which is literally burning away.

Yup, that's the one.

A hypothetical one at 10,000K would be melting, vaporizing and disintegrating until it's gone entirely.

Well, I have no idea what state the matter would be in at that temperature and pressure (maybe a weakly-ionised plasma) but the "disintegrating until it's gone" thing might take rather a long time. The escape velocity at the surface of A 6 would be over 46 km/s and the mean thermal velocity of silicon atoms (or ions) at 10000 K would be less than 4 km/s so I don't think they'd be lost all that quickly, especially if the temperature in the atmospheric column dropped a fair bit on the way up (as you'd expect, I guess). The solar wind (etc.) would "scrape" off a fair bit of the atmosphere as well (we actually had another thread on this overall topic a few weeks back), but nonetheless, I'd hazard a wild guess that a back-of-envelope lifetime estimate for such a planet would still be hundreds of millions of years and perhaps into the billions. (I haven't attempted this estimate yet )

(2500 K is pretty tame by comparison, with plenty of stuff on our own planet not even melting at that temperature. Silica apparently melts at around 2000 K and - at 1 atm pressure - boils at a little over 3000 K. Raise the pressure significantly and you'd just have a lake of molten silica sitting there happily with a cloud of silica vapour over it. Still very much not landable, btw, see below.)

It would be unlandable, unexplorable with SRV, and you definitely couldn't walk on its surface to collect anemone samples.

Unlandable, for sure, but A 6 is indeed listed in Spansh as unlandable (just like a gas giant ) so I'm not sure I understand your point here.

My suggested temperature cap at ~2500K is based on the approximate point at which a metal-rich planet of this type would turn into a pot of molten lava, with a surface too unstable for landing and exploring. I'm not too fussy about the exact number that ultimately gets picked, as long as it's more realistic.

But there are loads of cooler planets that are unlandable, including room-temperature water worlds.

Good catch! This makes me believe that the bug in question was introduced more recently, perhaps with the Odyssey expansion.

Maybe, but in my head the stellar forge hasn't been touched much (if at all) since day 1, by the very nature of the proc gen approach, so I'm not sure what can have caused the discrepancy. It's weird.
This brings me to a point I forgot to make in my first reply: I don't see how FD could credibly change this now even if they wanted to. Imposing a cap on planets that have already been scanned by players would break/invalidate the data they gathered and in some cases uploaded to community sites.

Usually, they have a totally ridiculous atmospheric pressure number. Which, to no surprise (or at least not mine) this one does. Looking at body A6 as listed on inara, it has a whopping 35 million atmospheric pressure, mostly composed of vaporized silicates. In other words, the surface burned up enough that the atmosphere is the planet's own material.

It's a crazy high pressure, but I'm not sure what's ridiculous (as in "impossible") about it...

 

[CMDR Galilean]

I'm inclined to think this is a stellar forge quirk because some fully procedural generation systems have bodies like this as well. Usually, they have a totally ridiculous atmospheric pressure number. Which, to no surprise (or at least not mine) this one does. Looking at body A6 as listed on inara, it has a whopping 35 million atmospheric pressure, mostly composed of vaporized silicates. In other words, the surface burned up enough that the atmosphere is the planet's own material.

Is it particularly realistic? Possibly not, but it seems to attempt creating a semblance thereof. I guessed when seeing these cases that there is a strange equilibrium due to the obscene pressure where the surface is sort of but not really solid under the heat. At least until some of that atmosphere is blown away. Of course this would also eventually result in there being no planet any more, but I'm not sure if it would happen on the time scales which can be observed in a single human lifespan. And likely is not part of the simulation.

Good eye. Some of the planet atmospheres in that system are definitely off the charts. Come to think, I've seen similar discrepancies before, such as planets that are supposedly 'icy' but have way too high temps, or vice-versa. Not sure if it makes sense reporting any of that considering the way the Issue Tracker works-- it would probably be faster to fly to Cambridge, grab ahold of CMDR Braben, drag him to a nearby pub, and explain to him (over a pint of strong ale of course) just how important this is to the veteran players.

 

[Kira Goto]

such as planets that are supposedly 'icy' but have way too high temps

Given how pressures work, this is also not too out-of-bounds. EG the iron in Earth's very inner core is solid even though the heat down there is way beyond its melting point at surface level*. Though of course I'm not in a position (or smart enough) to figure out if those supposed ice worlds with temperatures where those solids should be rather gaseous, are appropriately modelled to that.

*Extreme example just to illustrate.

 

[CMDR Galilean]

Yup, that's the one.

Well, I have no idea what state the matter would be in at that temperature and pressure (maybe a weakly-ionised plasma) but the "disintegrating until it's gone" thing might take rather a long time. The escape velocity at the surface of A 6 would be over 46 km/s and the mean thermal velocity of silicon atoms (or ions) at 10000 K would be less than 4 km/s so I don't think they'd be lost all that quickly, especially if the temperature in the atmospheric column dropped a fair bit on the way up (as you'd expect, I guess). The solar wind (etc.) would "scrape" off a fair bit of the atmosphere as well (we actually had another thread on this overall topic a few weeks back), but nonetheless, I'd hazard a wild guess that a back-of-envelope lifetime estimate for such a planet would still be hundreds of millions of years and perhaps into the billions. (I haven't attempted this estimate yet )

(2500 K is pretty tame by comparison, with plenty of stuff on our own planet not even melting at that temperature. Silica apparently melts at around 2000 K and - at 1 atm pressure - boils at a little over 3000 K. Raise the pressure significantly and you'd just have a lake of molten silica sitting there happily with a cloud of silica vapour over it. Still very much not landable, btw, see below.)

Unlandable, for sure, but A 6 is indeed listed in Spansh as unlandable (just like a gas giant ) so I'm not sure I understand your point here.

But there are loads of cooler planets that are unlandable, including room-temperature water worlds.

Maybe, but in my head the stellar forge hasn't been touched much (if at all) since day 1, by the very nature of the proc gen approach, so I'm not sure what can have caused the discrepancy. It's weird.
This brings me to a point I forgot to make in my first reply: I don't see how FD could credibly change this now even if they wanted to. Imposing a cap on planets that have already been scanned by players would break/invalidate the data they gathered and in some cases uploaded to community sites.

It's a crazy high pressure, but I'm not sure what's ridiculous (as in "impossible") about it...

My original complaint is with planet A 7 a, which is landable although it should not be at that surface temperature. A 6 was merely given as another weird example in that system. Different problem, but perhaps with a common source.

 

[CMDR Galilean]

Given how pressures work, this is also not too out-of-bounds. EG the iron in Earth's very inner core is solid even though the heat down there is way beyond its melting point at surface level*. Though of course I'm not in a position (or smart enough) to figure out if those supposed ice worlds with temperatures where those solids should be rather gaseous, are appropriately modelled to that.

*Extreme example just to illustrate.

Fair point.

 

[Kira Goto]

It's a crazy high pressure, but I'm not sure what's ridiculous (as in "impossible") about it...

Just that it’s obscenely high and for it to be still classed as a high metal content or metal-rich world than a (small) gas giant. But then again, I don’t know exactly where humans draw the line.

… and apparently there’s an even more absurd one out there with over a trillion pressures of iron vapor, or was at time of that post's creation at least. Now that’s metal. … sorry.

 

[Neilski]

My original complaint is with planet A 7 a, which is landable although it should not be at that surface temperature.

Ahhh. This brings us back to the weird data discrepancy. I'm inclined to guess that the game client showed you some mangled data for that planet - partially mixing data from other bodies? You can find out "sort-of for sure" by looking in your game journal for the entries when you scanned it. I suspect they will confirm that A 7 a has a "mere" 1435 K surface temperature (mostly because I'm assuming that Spansh got its data from you).

Just that it’s obscenely high and for it to be still classed as a high metal content or metal-rich world than a (small) gas giant. But then again, I don’t know exactly where humans draw the line.

Yes, fair point, and no me neither

… and apparently there’s an even more absurd one out there with over a trillion pressures of iron vapor, or was at time of that post's creation at least. Now that’s metal. … sorry.

Wow, that's starting to feel silly high now for sure. (And ROFL!)

 

[Morbad]

Strictly speaking, the only thing required for a planet to be 10k or hotter is an equilibrium temperature of that high and enough gravity to keep it together. I can imagine such surface temperatures on worlds with sufficient internal heat and suitably thick atmospheres.

No doubt the game is generating many impossible worlds, but many of those that may seem off at first glance aren't completely far fetched.

Given how pressures work, this is also not too out-of-bounds. EG the iron in Earth's very inner core is solid even though the heat down there is way beyond its melting point at surface level*. Though of course I'm not in a position (or smart enough) to figure out if those supposed ice worlds with temperatures where those solids should be rather gaseous, are appropriately modelled to that.

*Extreme example just to illustrate.

Looking up phase diagrams for the material in question can serve as a quick sanity check.

 

[CMDR Galilean]

Ahhh. This brings us back to the weird data discrepancy. I'm inclined to guess that the game client showed you some mangled data for that planet - partially mixing data from other bodies? You can find out "sort-of for sure" by looking in your game journal for the entries when you scanned it. I suspect they will confirm that A 7 a has a "mere" 1435 K surface temperature (mostly because I'm assuming that Spansh got its data from you).

Nope, I'm not using any data upload tools. But you're right about the log - it lists the same temp as INARA site. However, the gravity is waay off. Make sense of it if you can.

{ "timestamp":"2025-05-20T18:58:10Z", "event":"Scan", "ScanType":"Detailed", "BodyName":"S171 43 A 7 a", "BodyID":14, "Parents":[ {"Star":13}, {"Null":12}, {"Star":1}, {"Null":0} ], "StarSystem":"S171 43", "SystemAddress":178618511, "DistanceFromArrivalLS":1415.424257, "TidalLock":true, "TerraformState":"", "PlanetClass":"Metal rich body", "Atmosphere":"", "AtmosphereType":"None", "Volcanism":"major silicate vapour geysers volcanism", "MassEM":0.031500, "Radius":1653707.625000, "SurfaceGravity":4.591009, "SurfaceTemperature":1434.972168, "SurfacePressure":0.000000, "Landable":true, "Materials":[ { "Name":"iron", "Percent":34.992847 }, { "Name":"nickel", "Percent":26.467121 }, { "Name":"manganese", "Percent":14.451689 }, { "Name":"zinc", "Percent":9.509746 }, { "Name":"vanadium", "Percent":8.593025 }, { "Name":"niobium", "Percent":2.391575 }, { "Name":"molybdenum", "Percent":2.285012 }, { "Name":"antimony", "Percent":1.308977 } ], "Composition":{ "Ice":0.000000, "Rock":0.000000, "Metal":1.000000 }, "SemiMajorAxis":1347270846.366882, "Eccentricity":0.003216, "OrbitalInclination":0.643958, "Periapsis":340.377539, "OrbitalPeriod":68291.271925, "AscendingNode":-65.519908, "MeanAnomaly":71.839030, "RotationPeriod":68291.964923, "AxialTilt":0.399152, "WasDiscovered":true, "WasMapped":true }

 

[Neilski]

Nope, I'm not using any data upload tools. But you're right about the log - it lists the same temp as INARA site. However, the gravity is waay off. Make sense of it if you can.

{ "timestamp":"2025-05-20T18:58:10Z", "event":"Scan", "ScanType":"Detailed", "BodyName":"S171 43 A 7 a", "BodyID":14, "Parents":[ {"Star":13}, {"Null":12}, {"Star":1}, {"Null":0} ], "StarSystem":"S171 43", "SystemAddress":178618511, "DistanceFromArrivalLS":1415.424257, "TidalLock":true, "TerraformState":"", "PlanetClass":"Metal rich body", "Atmosphere":"", "AtmosphereType":"None", "Volcanism":"major silicate vapour geysers volcanism", "MassEM":0.031500, "Radius":1653707.625000, "SurfaceGravity":4.591009, "SurfaceTemperature":1434.972168, "SurfacePressure":0.000000, "Landable":true, "Materials":[ { "Name":"iron", "Percent":34.992847 }, { "Name":"nickel", "Percent":26.467121 }, { "Name":"manganese", "Percent":14.451689 }, { "Name":"zinc", "Percent":9.509746 }, { "Name":"vanadium", "Percent":8.593025 }, { "Name":"niobium", "Percent":2.391575 }, { "Name":"molybdenum", "Percent":2.285012 }, { "Name":"antimony", "Percent":1.308977 } ], "Composition":{ "Ice":0.000000, "Rock":0.000000, "Metal":1.000000 }, "SemiMajorAxis":1347270846.366882, "Eccentricity":0.003216, "OrbitalInclination":0.643958, "Periapsis":340.377539, "OrbitalPeriod":68291.271925, "AscendingNode":-65.519908, "MeanAnomaly":71.839030, "RotationPeriod":68291.964923, "AxialTilt":0.399152, "WasDiscovered":true, "WasMapped":true }

That all looks like a match to me. The gravity is just in different units (this is a constant annoyance, actually) - on Spansh and Inara it's in units of Earth gravities, while in the journal it's in m/s/s, but only Inara actually mentions the units. (Nice one Artie!)

 

[CMDR Galilean]

That all looks like a match to me. The gravity is just in different units (this is a constant annoyance, actually) - on Spansh and Inara it's in units of Earth gravities, while in the journal it's in m/s/s, but only Inara actually mentions the units. (Nice one Artie!)

Roger that. Not sure what to make of it now concerning the temperature discrepancy, though. The bug appears to be in the UI rather than the procedural generation? In that case I'll just edit the bug report.

 

[DjVortex]

While exploring S171 43, I came across a few planets with reported surface temperature over 10,000K, which is obviously a procedural generation glitch.

Go to the first planet of the system CSI+46-20087.

It's a landable atmosphered planet with a day-side surface temperature of over 18000 K.

It's also beautiful, especially if you land on it approaching from the night side, with the star just above the horizon.

 

[Agony_Aunt]

Out of all the stellar forge quirks this is the one that gets to you?

Not, perhaps, earthlike worlds around neutron stars? Or the fact that neutron stars are one of the best places to find ELWs and WWs?

Or ELW around black holes?

its worth keeping in mind, FD only had the chance to reroll the stellar forge before release. After, they couldn't keep rerolling every time someone found an issue with it. Sure, maybe they could tweak temps on planets or something, but not a proper reroll to get rid of the really really silly stuff.

As I understand it, FD were considering a reroll during gamma, but when it was under consideration, a lot of people (myself included) said "Go with it! We already started exploring and putting our names on systems." In the end, they didn't reroll, so we are more or less stuck with the galaxy we have, all the silly stuff included.