1. My headcanon is that Polyphemus' inward migration allowed it to capture much more rocky material to form many large moons. As for the clouds, it's a water-cloud jovian; it should be slightly less blue and more white, but I'll chalk it up to artistic licence. 2. One funny point about the atmosphere is that with so high CO2 content, the air would be deadly to humans even without the hydrogen sulfide, making it totally unnecessary. Also, it would smell like hell there. I've been to Iceland's geothermal regions and the smell there was pretty bad at much lower levels. 3. Unobtanium is an obvious mcguffin, it has to be there for the story to work (otherwise, what else would push humans to build antimatter starships to go there in force, if they can't actually live in that world? For that reason, I am willing to suspend disbelief quite a lot.
even without unobtanium pandora is too valuable to let go, we'd most likely establish major human colony for long term survival of our species ASAP especially when earth is already unhabitable, unlike mars pandora is almost identical to earth in every aspect, people just need air filter and they can live relatively free and comfortable as they live on earth
@_martian101 The trouble is it is in many ways more hostile than an inert world due to toxic air and hostile wildlife. Depending on how different pandora's life is from earth life biochemically, humans likely couldn't even eat native flora (it'd be toxic or at the very least inedible/not nutritious). For humans, it would be easier to terraform Mars or, hell, even Venus than to fly 4.37 light years to settle a hostile world where unaided humans wouldn't survive a minute.
@@Winner8501 not necesarilly true, hostile environment like lethal wildlife is not always a norm, there's many locations in pandora with less ecosystem where human can live relatively safe, and even in the rain forest human can still live inside their residental and industrial area, also pandora is almost same as earth in biochemistry the only exotic substance there is unobtanium the rest is just common on earth so native biosphere would very likely have the same nutrition or even better than on earth, since it's way more developed and very rich in biodiversity, even if most of plants and animals is toxic there's still vast amount of species that could be safe to eat, and we can still extract nutrition from toxic species even breed engineered native species for consumption if we want to considering how advanced the bioengineering technology has became in avatar universe, that if we only depend on native species, we could bring earth species and grow it indoor as well and it's still way better than doing it on mars, there's decent gravity, water source, air, magnetic field, essentially everything is already provided, it's too far for regular colony? we can start from little, then build necesary infrastructure like laser beam that accelerate isv from earth so no need for antimatter engine, no engine mean more space and less weight, mean more cargo and suplies,we can build solid civilization way faster on pandora than mars, pandora is undoubtedly much more easy to colonize than terraform the entirely dead planets.
Small correction on the color of Polyphemus For a gas giant that size we expect the coloration to be determined by the clouds in its atmosphere. This is the case for Jupiter and Saturn as well. In the case of Polyphemus clouds of water would likely form the highest layer, giving it a white coloration, with possible blue tints of rayleigh-scattering.
I wonder if some of the oddities of Pandora may have actually been shaped by intelligent forces. After all, all of the lifeforms on it are technically connected into one sapient superorganism (Eywa). Together with the unobtainium, it makes you wonder if maybe the whole moon was a failed experiment by some spacefaring empire millions of years ago, like the planet from Sid Meier’s Alpha Centauri.
Theoretically couldn't pandora be a captured planet? It would explain its large size and why there's so few minor moons if albeit polyphemus does have far more major moons than what you'd expect in such a scenario, I'd guess there'd should probably be only two others maximum
However, when it comes to a planet being captured by a gas giant, there are many consequences. The capturing of a planet will not only result in the orbits of a gas giant's native moons to be disrupted, but will also cause them to either be ejected, or collide with one or another (or perhaps colliding with the parent planet or the now-captured planet.).
@titan-1802 yes, I stayed that saying I believe that could be why it only has seven minor moons although I found it strange it had kept six major moons in such a scenario
Perhaps a super-Earth was captured early in the star system's development and was shattered by Polyphemus' tidal forces when it crossed its Roche limit, the result of which condensed into Polyphemus' current moons, most notably Pandora.
I just discovered your channel and binged most of the videos, it's already one of my favourites! As an aspiring science-fiction writer I'd love to see something like a 101 guide to the very basics of worldbuilding stars, planets, and moons. 💜🌕
we have very limited data about how gas giants and their moons can form, perhaps "one big rocky moon and very few tiny moons" is a rare but possible outcome in stellar system formation. the abundance of xenon gas as well, if i was to write it i'd connect that to the existence of unobtanium.
I certainly hope so. I don't feel like that's too high a mark to hit. There isn't a category that no planet has gotten a +1 in. I'm confident that eventually I'll find a planet that nails all five, even if it's by accident. (+5 points would be an S-grade on my scale.)
I'm so glad to see another video about my beloved franchise 😊 Just wanted to point out one thing. Avatar survival guide is no longer canon. It was discarded because that book was originally rushed and some information in that book doesn't longer make sense. Like those CO2 levels. I think they are planning to change it to a more believable level. There are two more newer books, Avatar a visual dictionary and Avatar a visual exploration but unfortunately, there isn't that much information. Avatar lore is now in some sort of vacuum. Cameron has a huge book called pandorapedia but it isn't public. And only a fraction of it is either online or in those mentioned books. Oh and yes, Pandora is tidally locked. It was confirmed also by developers in one of the behind the scene video.
i'm more interested in the possibility that pandora is actually an engineered world by ancient civilization, it would explain so many things including how complex life can develop in such unlikely environment and how can eywa be a thing, maybe eventually james cameron will tell us that this is how we should use technology as he portrayed na'vi as somekind of advanced civilization who choose to go back to nature after environmental collapse created by their own technology
As an aspiring writer, my dream now includes getting a lore feature on Alien Planetology. This channel made me double down on my research when it comes to building worlds in hopes that I can get a high rating lol.
i wonder if the blue hue of polyphemus has to do with the fact that being this close to its star, water clouds and haze replace ammonium clouds that we see in jupiter, giving it a white-ish, perhaps even blue-ish (due to water being very slightly blue in colour and polyphemus would likely possess abundant water clouds in the atmosphere)
Polyphemus is very likely to have a higher water content than Jupiter. It's not unlikely that you might see a blueish haze toward the edges (limbs) of its disk as light refracted through the gaseous water; and condensed water vapor could form white clouds, which could give it a higher occurrence of white banding and storm cells than what we see in Jupiter. Some of these could even have a blueish tint to them, but water cannot make up a high enough fraction of a gas giant's upper atmosphere to color the whole planet such a deep blue.
Does anyone know of a near or fully Canon topography map of Pandora? Ideally, a greyscale. I was wondering if could be possible to run an exoplasim climate simulation of the moon
There is that one texture map of Pandora from Avatar: The Game, but that game is considered non-canon. That is however the closest canonical map of Pandora we'll get. But as Taro mentioned, we might one day will get an actual map of Pandora.
so in the first Avatar movie they didn't really address anything to do with the stellar objects in Pandora's skies at all. in the second film, they finally addressed the eclipses that would inevitably happen on the planet-facing side of the moon. however, one thing that still bothers me is that they never really addressed the other stars in their system and how those would affect the sky. maybe Proxima would be too small to make a big change, but surely Alpha Centauri B would be way brighter than any star in our Earth sky, right? would light from Alpha Centauri B be strong enough to light parts of Pandora even at night, during some times of year? could it give the sky a twilight-like hue? this is something I always thought was cool and wondered about S-type vs P-type planets in binary systems
@@DiegoElizondo Exactly. In the parts of the year when Alpha Centauri B is visible during the night, it should be much much brighter than the full moon. (Depending on its current distance). But I recall reading in the Survivalist Guide (?) or Pandorapaedia (not sure) that truly dark nights are very rare on Pandora, exactly because of all the celestial objects illuminating the skies (Polyphemus, other moons, AC B, powerful auroras).
@@Winner8501another thing that's interesting is that so many animals/plants are bioluminescent on Pandora. obv I know that they did this because it looks cool, and I'll agree that rule of cool does justify it imo. but realistically, having three suns, the planet's terrestrial life would definitely not need this
If my math is correct, at its closest, ACB would be 251 times dimmer than our Sun, which is equivalent to about 1722 times brighter than the full Moon. So yeah, for awhile there, "nights" would be very bright. When at its farthest, ACB would be a magnitude -3.32 star---a little brighter than Mars.
@Alien_Planetology The second number doesn't seem right. At its farthest, AC-B is about the distance of Pluto. The sun at this distance is much much brighter than Mars and AC-B isn't *that* much dimmer.
2:05 It is actually extremely unlikely that all large moons are tidally locked to their planets. Yes, all moons in our own star system are, but that doesn't have to be the case in younger star systems. Tidal locks are not something that happens when the moon forms around the planet, it forms over time because the much larger planet slows the rotation of the moon (the same happens to planets in regards to the sun btw - Earth will eventually be tidally locked to the sun; Mercury's rotation is already incredibly slow with only 3 days in a Mercury year - which equals 88 Earth days. Venus is even closer to being tidally locked with a Venus year only being less than 2 Venus days long which equals 224.7 Earth days). Another possible explanation than just the age of the system for a moon not being tidally locked to its planet is that the moon was comparatively recently captured by the planet.
Considering the star system is older than ours by a billion years while not impossible it's likely it would have settled down so there'd be few orbits crossing, anyways due to orbiting a gas giant you'd expect it to be tidally locked relatively fast
I never liked that the "denser atmosphere-lower gravity" excuse for existence of not just extremely large, but also actively flapping, fliying creatures on Pandora. The planet's gravity is only like 10-15% lower than that of Earth and the atmosphere is only 20% denser and yet, the surface pressure is 0.9 of Earth's.
@@Cat-On-Wabdermelon Oh that explains why I wasnt subscribe to this one and why some of his old videos are missing, like a bunch of Star Trek and Star Wars ones.
I feel for you. That's the problem with cloning existing planets for speculative planets: they are in the state we see them in because of their physical parameters; so we can't keep those parameters and realistically expect them to be in a different state. If you want to make such a world, you're probably going to have to ignore realism to some extent.
@@Alien_Planetology i am currently considering adding more mass and density, since i want it to be as scientifically viable as possible. though i would like to note this Mars is not Earth-like as at the equator temperatures would be subtropical at best and the average sea level air pressure and oxygen concentrration would be equivalent to high altitude Andes settlements.
Theoretically you could have a mars sized planet with complex surface life if it was captured recently, it took mars a few tens of millions of years to have its atmosphere stripped so if your mars sized planet was rouge then it could've developed complex life then as it was captured and became subject to its star's solar wind then if through some stroke of luck life evolves fast enough you could theoretically get land life before the atmosphere is stripped although you would have to worry about radiation, if it's a moon of a gas giant not a planet then if it orbits close enough it could borrow its parents magnet field although you'd need to be careful for radiation belts
@@dontforgetyoursunscreen in my vision for this alternate Mars, all life is confined to the seas and lakes and coastlines around them, since due to a lighter atmosphere it can't survive above a certain altitude. the three things i want for this is complex life, a sea level atmosphere that humans can breathe in without (much) equipment and flowing water.
Wonder if two terrestrial planets with similar masses can orbit each other in a binary planetary system.I mean there are binary stars thats have close to the same masses so I assume the same can apply to planets
It is extremely unlikely for large planets, but Pluto and Charon get pretty close to it… which are a large dwarf planet and its major moon. But alot of things would have to go almost perfect to keep the orbit stable that it’s unlikely; mainly being of nearly identical masses forming at exactly the same time is almost the same orbit path close enough to tug each other into an orbit. It not impossible, just extremely unlikely… so if we do find it, I personally would be interested in studying the phenomenon
@@Alien_Planetology I'm looking forward to this!! I am personally working on a setting within a double/binary planet system and I spent way, waaay too much time doing all the math to work out how frequently eclipses would happen, when/where, and for how long. I've always loved the concept of them
I mean Holy Terra is literally just Earth. Nocturne is has a hazy atmosphere. And the Tau Homeworld is a basically slightly smaller somewhat arid Earth
Armageddon (and the other worlds of its system) seems to be the only other known planet in Warhammer to have lots of data (I.E. its diameter, gravity, temperature, and orbital distance).
@@titan-1802 its a shame, because there are very interesting planets, but obviously exactly what the planet is like isnt super important if you have an Ork infestation
@@PlutonianEmpire Kind of, yeah. I try to pick worlds that are well known to a large group of people, so that viewers have a vested interest in what I have to say about them.
I would love to! Subnautica is one of my favorite video games of all time. Unfortunately, there is virtually no astronomical data available for the planet, so I can't make a video like this. But I hope to make a video of some kind about it eventually.
Could you grade my planet please? It’s my first attempt at making a planet with its properties listed so expect inaccuracies as I’m terrible at maths Planet: Darwin Prime Moons: 1 major moon Star: 36 Ophiuchi-C Day length: 30 hrs Year length: 216 days Radius: 6,997,381 m Mean density: 5042 kg/m3 Mass: 7.236007869529 x 10^24
The geophysical realism is excellent (+1). All your math checks out and your planet is well within the realistic mass/size range for a terrestrial planet. You didn't give your planet's surface gravity, but if anyone is interested, it is 9.8636 m/s2 or 1.0044 G. The orbital realism is good (+1). Given 36 Ophi C's mass of 0.71 M_Sol, your planet's average orbital distance is 9.4034x10^10 m or 0.6286 AU. You did not provide any data for the climate realism (0). I know you probably haven't gotten that far yet, so consider this score temporary. Based off your planet's distance from its star and the star's luminosity, your planet only receives about 23% as much energy as Earth does. So, as it sits now, your planet is likely to be very cold. You did not provide enough data for the satellite realism (0). Having only one major moon is quite realistic, but without data about the moon's geophysical or orbital parameters, I can't score its realism. Once again, I'll consider this a temporary score. Its stellar realism is good (+1). Being a spectral type K5 main-sequence star, 36 Ophiuchi C is a good type of star to choose. However, at between 0.6 and 1.8 billion years old, it's a very young star. So I would consider it unlikely for a planet around it to support anything more than single-cell life. With a score of +3 points, your planet would get a B-grade. It's missing some important data, but what you have so far is really good. Keep up the great work!
@@Alien_PlanetologyThank you so much! I’ll be sure to provide data for those things and change it to be around an older star, since I want the planet to be tropical what distance and year length would it have to be to be said tropical temperature?
@@Cat-On-Wabdermelon It depends on the luminosity of the star you choose. You can calculate the orbital distance (in meters) by taking the square root of the star's luminosity (in Watts) divided by 4 times pi times the desired stellar flux (in Watts per square meter). Earth's stellar flux is equal to 1361 W/m2. If your planet has similar atmospheric and surface properties to Earth, then to get the warmer average temperature you want, you'll need a higher stellar flux value. Perhaps around 1470 W/m2. Once you have the orbital distance, you can calculate the orbital period of the planet by taking the square root of 4 times pi squared, times your orbital distance cubed, divided by the Gravitational Constant (6.674 x 10^-11) times the mass of your star (in kilograms).
@@Alien_Planetology by chance would Toliman or any other of the ophiuchi stars make a good K star to place Darwin Prime around since you said ophiuchi C was too young
Are you an engineer or otherwise engaged in scientific duties at the Marshall Space Flight Center, i.e. a NASA employee? Or, are you just a very well-informed, knowledgeable and intelligent hobbyist?
@ Why does an ostensible adult have an anime avatar? Surely you know that you intimate to others many negative character traits by utilizing an anime avatar. It matters in so far as I am interested in him as a human. I’m not challenging him on credentials, rather I am fascinated in his knowledge and wish to understand better whence it springs.
@ old comment got deleted for referencing a certain historical event as to why I refuse to let bad people win and ruin a thing I care about, not anime but this specific image.
@@Dianasaurthemelonlord7777 It seems criminal, on the part of UA-cam, that you can’t reply to me in plain language and reference any thing you wish without being censored. Free speech keep people free.
1. My headcanon is that Polyphemus' inward migration allowed it to capture much more rocky material to form many large moons. As for the clouds, it's a water-cloud jovian; it should be slightly less blue and more white, but I'll chalk it up to artistic licence.
2. One funny point about the atmosphere is that with so high CO2 content, the air would be deadly to humans even without the hydrogen sulfide, making it totally unnecessary. Also, it would smell like hell there. I've been to Iceland's geothermal regions and the smell there was pretty bad at much lower levels.
3. Unobtanium is an obvious mcguffin, it has to be there for the story to work (otherwise, what else would push humans to build antimatter starships to go there in force, if they can't actually live in that world? For that reason, I am willing to suspend disbelief quite a lot.
even without unobtanium pandora is too valuable to let go, we'd most likely establish major human colony for long term survival of our species ASAP especially when earth is already unhabitable, unlike mars pandora is almost identical to earth in every aspect, people just need air filter and they can live relatively free and comfortable as they live on earth
@_martian101 The trouble is it is in many ways more hostile than an inert world due to toxic air and hostile wildlife. Depending on how different pandora's life is from earth life biochemically, humans likely couldn't even eat native flora (it'd be toxic or at the very least inedible/not nutritious).
For humans, it would be easier to terraform Mars or, hell, even Venus than to fly 4.37 light years to settle a hostile world where unaided humans wouldn't survive a minute.
@@Winner8501 not necesarilly true, hostile environment like lethal wildlife is not always a norm, there's many locations in pandora with less ecosystem where human can live relatively safe, and even in the rain forest human can still live inside their residental and industrial area, also pandora is almost same as earth in biochemistry the only exotic substance there is unobtanium the rest is just common on earth so native biosphere would very likely have the same nutrition or even better than on earth, since it's way more developed and very rich in biodiversity, even if most of plants and animals is toxic there's still vast amount of species that could be safe to eat, and we can still extract nutrition from toxic species even breed engineered native species for consumption if we want to considering how advanced the bioengineering technology has became in avatar universe, that if we only depend on native species, we could bring earth species and grow it indoor as well and it's still way better than doing it on mars, there's decent gravity, water source, air, magnetic field, essentially everything is already provided, it's too far for regular colony? we can start from little, then build necesary infrastructure like laser beam that accelerate isv from earth so no need for antimatter engine, no engine mean more space and less weight, mean more cargo and suplies,we can build solid civilization way faster on pandora than mars, pandora is undoubtedly much more easy to colonize than terraform the entirely dead planets.
Small correction on the color of Polyphemus
For a gas giant that size we expect the coloration to be determined by the clouds in its atmosphere. This is the case for Jupiter and Saturn as well. In the case of Polyphemus clouds of water would likely form the highest layer, giving it a white coloration, with possible blue tints of rayleigh-scattering.
I wonder if some of the oddities of Pandora may have actually been shaped by intelligent forces. After all, all of the lifeforms on it are technically connected into one sapient superorganism (Eywa). Together with the unobtainium, it makes you wonder if maybe the whole moon was a failed experiment by some spacefaring empire millions of years ago, like the planet from Sid Meier’s Alpha Centauri.
Theoretically couldn't pandora be a captured planet? It would explain its large size and why there's so few minor moons if albeit polyphemus does have far more major moons than what you'd expect in such a scenario, I'd guess there'd should probably be only two others maximum
However, when it comes to a planet being captured by a gas giant, there are many consequences.
The capturing of a planet will not only result in the orbits of a gas giant's native moons to be disrupted, but will also cause them to either be ejected, or collide with one or another (or perhaps colliding with the parent planet or the now-captured planet.).
@titan-1802 yes, I stayed that saying I believe that could be why it only has seven minor moons although I found it strange it had kept six major moons in such a scenario
Perhaps a super-Earth was captured early in the star system's development and was shattered by Polyphemus' tidal forces when it crossed its Roche limit, the result of which condensed into Polyphemus' current moons, most notably Pandora.
I just discovered your channel and binged most of the videos, it's already one of my favourites! As an aspiring science-fiction writer I'd love to see something like a 101 guide to the very basics of worldbuilding stars, planets, and moons. 💜🌕
Thanks! You're in luck. I've been working on a series like that for quite awhile now and it'll be premiering early in the new year.
we have very limited data about how gas giants and their moons can form, perhaps "one big rocky moon and very few tiny moons" is a rare but possible outcome in stellar system formation. the abundance of xenon gas as well, if i was to write it i'd connect that to the existence of unobtanium.
wonder if they'll ever come up with a world that gets an A
I certainly hope so. I don't feel like that's too high a mark to hit. There isn't a category that no planet has gotten a +1 in. I'm confident that eventually I'll find a planet that nails all five, even if it's by accident. (+5 points would be an S-grade on my scale.)
@@Alien_Planetology you'd think with the money spent on some of these projects they'd kick in a few bucks to the "hey make a realistic system" devs
@@Alien_PlanetologyHow would you rank Earth in the films that depict it (most of them)
@@jper4911too busy paying the overpaid actors and consultants.
I'm so glad to see another video about my beloved franchise 😊 Just wanted to point out one thing. Avatar survival guide is no longer canon. It was discarded because that book was originally rushed and some information in that book doesn't longer make sense. Like those CO2 levels. I think they are planning to change it to a more believable level. There are two more newer books, Avatar a visual dictionary and Avatar a visual exploration but unfortunately, there isn't that much information. Avatar lore is now in some sort of vacuum. Cameron has a huge book called pandorapedia but it isn't public. And only a fraction of it is either online or in those mentioned books. Oh and yes, Pandora is tidally locked. It was confirmed also by developers in one of the behind the scene video.
i'm more interested in the possibility that pandora is actually an engineered world by ancient civilization, it would explain so many things including how complex life can develop in such unlikely environment and how can eywa be a thing, maybe eventually james cameron will tell us that this is how we should use technology as he portrayed na'vi as somekind of advanced civilization who choose to go back to nature after environmental collapse created by their own technology
As an aspiring writer, my dream now includes getting a lore feature on Alien Planetology. This channel made me double down on my research when it comes to building worlds in hopes that I can get a high rating lol.
i wonder if the blue hue of polyphemus has to do with the fact that being this close to its star, water clouds and haze replace ammonium clouds that we see in jupiter, giving it a white-ish, perhaps even blue-ish (due to water being very slightly blue in colour and polyphemus would likely possess abundant water clouds in the atmosphere)
Polyphemus is very likely to have a higher water content than Jupiter. It's not unlikely that you might see a blueish haze toward the edges (limbs) of its disk as light refracted through the gaseous water; and condensed water vapor could form white clouds, which could give it a higher occurrence of white banding and storm cells than what we see in Jupiter. Some of these could even have a blueish tint to them, but water cannot make up a high enough fraction of a gas giant's upper atmosphere to color the whole planet such a deep blue.
Does anyone know of a near or fully Canon topography map of Pandora? Ideally, a greyscale. I was wondering if could be possible to run an exoplasim climate simulation of the moon
Hi, we don't have a map yet. But people from lightstorm said that one day we will :)
There is that one texture map of Pandora from Avatar: The Game, but that game is considered non-canon.
That is however the closest canonical map of Pandora we'll get. But as Taro mentioned, we might one day will get an actual map of Pandora.
so in the first Avatar movie they didn't really address anything to do with the stellar objects in Pandora's skies at all. in the second film, they finally addressed the eclipses that would inevitably happen on the planet-facing side of the moon. however, one thing that still bothers me is that they never really addressed the other stars in their system and how those would affect the sky. maybe Proxima would be too small to make a big change, but surely Alpha Centauri B would be way brighter than any star in our Earth sky, right? would light from Alpha Centauri B be strong enough to light parts of Pandora even at night, during some times of year? could it give the sky a twilight-like hue? this is something I always thought was cool and wondered about S-type vs P-type planets in binary systems
@@DiegoElizondo Exactly. In the parts of the year when Alpha Centauri B is visible during the night, it should be much much brighter than the full moon. (Depending on its current distance).
But I recall reading in the Survivalist Guide (?) or Pandorapaedia (not sure) that truly dark nights are very rare on Pandora, exactly because of all the celestial objects illuminating the skies (Polyphemus, other moons, AC B, powerful auroras).
@@Winner8501another thing that's interesting is that so many animals/plants are bioluminescent on Pandora. obv I know that they did this because it looks cool, and I'll agree that rule of cool does justify it imo. but realistically, having three suns, the planet's terrestrial life would definitely not need this
@@DiegoElizondo or the constantly changing and non predictable amount of light somehow actually caused bioluminescence to develop
If my math is correct, at its closest, ACB would be 251 times dimmer than our Sun, which is equivalent to about 1722 times brighter than the full Moon. So yeah, for awhile there, "nights" would be very bright. When at its farthest, ACB would be a magnitude -3.32 star---a little brighter than Mars.
@Alien_Planetology The second number doesn't seem right. At its farthest, AC-B is about the distance of Pluto. The sun at this distance is much much brighter than Mars and AC-B isn't *that* much dimmer.
We haven't discovered more moons around Polyphemus yet!
2:05 It is actually extremely unlikely that all large moons are tidally locked to their planets. Yes, all moons in our own star system are, but that doesn't have to be the case in younger star systems. Tidal locks are not something that happens when the moon forms around the planet, it forms over time because the much larger planet slows the rotation of the moon (the same happens to planets in regards to the sun btw - Earth will eventually be tidally locked to the sun; Mercury's rotation is already incredibly slow with only 3 days in a Mercury year - which equals 88 Earth days. Venus is even closer to being tidally locked with a Venus year only being less than 2 Venus days long which equals 224.7 Earth days).
Another possible explanation than just the age of the system for a moon not being tidally locked to its planet is that the moon was comparatively recently captured by the planet.
Considering the star system is older than ours by a billion years while not impossible it's likely it would have settled down so there'd be few orbits crossing, anyways due to orbiting a gas giant you'd expect it to be tidally locked relatively fast
Vulcan from Star Trek would be a good pick I think.
@@oisinm332 Sadly, there isn't enough astronomical data available for it.
@Alien_Planetology That's a pity, oh well.
I've been waiting for this 😊😊
I hope you enjoyed it!
Also Pandora with carbon dioxide this high (>18%) in the atmosphere should have already had venusian style runaway greenhouse effect long ago
unless the distance is further than earth to the sun
I never liked that the "denser atmosphere-lower gravity" excuse for existence of not just extremely large, but also actively flapping, fliying creatures on Pandora.
The planet's gravity is only like 10-15% lower than that of Earth and the atmosphere is only 20% denser and yet, the surface pressure is 0.9 of Earth's.
the largest possible size for a flying animal in this planet has to be only a little bigger than the largest of Quetzalcoatlus
I would understand if Pandora had like gravity of 0.4-0.6 G and 8-10 atm.
I wonder if we will ever have an A or B rated planet
I thought u had done this one already
His old channel got deleted
@@Cat-On-Wabdermelon Oh that explains why I wasnt subscribe to this one and why some of his old videos are missing, like a bunch of Star Trek and Star Wars ones.
I want to make a naturally livable alternate mars and this series inspires me to pursue it but the low density and atmospheric loss is bothersome
I feel for you. That's the problem with cloning existing planets for speculative planets: they are in the state we see them in because of their physical parameters; so we can't keep those parameters and realistically expect them to be in a different state. If you want to make such a world, you're probably going to have to ignore realism to some extent.
@@Alien_Planetology i am currently considering adding more mass and density, since i want it to be as scientifically viable as possible. though i would like to note this Mars is not Earth-like as at the equator temperatures would be subtropical at best and the average sea level air pressure and oxygen concentrration would be equivalent to high altitude Andes settlements.
Theoretically you could have a mars sized planet with complex surface life if it was captured recently, it took mars a few tens of millions of years to have its atmosphere stripped so if your mars sized planet was rouge then it could've developed complex life then as it was captured and became subject to its star's solar wind then if through some stroke of luck life evolves fast enough you could theoretically get land life before the atmosphere is stripped although you would have to worry about radiation, if it's a moon of a gas giant not a planet then if it orbits close enough it could borrow its parents magnet field although you'd need to be careful for radiation belts
@@dontforgetyoursunscreen in my vision for this alternate Mars, all life is confined to the seas and lakes and coastlines around them, since due to a lighter atmosphere it can't survive above a certain altitude. the three things i want for this is complex life, a sea level atmosphere that humans can breathe in without (much) equipment and flowing water.
@@ghostoftheoldworld5104 if it was a recently captured planet or a moon of a gas giant it could work
Really good .loved it.
Wonder if two terrestrial planets with similar masses can orbit each other in a binary planetary system.I mean there are binary stars thats have close to the same masses so I assume the same can apply to planets
It is extremely unlikely for large planets, but Pluto and Charon get pretty close to it… which are a large dwarf planet and its major moon. But alot of things would have to go almost perfect to keep the orbit stable that it’s unlikely; mainly being of nearly identical masses forming at exactly the same time is almost the same orbit path close enough to tug each other into an orbit.
It not impossible, just extremely unlikely… so if we do find it, I personally would be interested in studying the phenomenon
They can! They are called double planets (sometimes binary planets.) I plan to do a video about them at some point.
@@Alien_Planetology I'm looking forward to this!! I am personally working on a setting within a double/binary planet system and I spent way, waaay too much time doing all the math to work out how frequently eclipses would happen, when/where, and for how long. I've always loved the concept of them
Do warhammer planets have info on them?
I mean Holy Terra is literally just Earth.
Nocturne is has a hazy atmosphere. And the Tau Homeworld is a basically slightly smaller somewhat arid Earth
Armageddon (and the other worlds of its system) seems to be the only other known planet in Warhammer to have lots of data (I.E. its diameter, gravity, temperature, and orbital distance).
@@titan-1802 its a shame, because there are very interesting planets, but obviously exactly what the planet is like isnt super important if you have an Ork infestation
Is there a minimum amount of fame a planet has to have in order to post a video on it, by any chance?
@@PlutonianEmpire Kind of, yeah. I try to pick worlds that are well known to a large group of people, so that viewers have a vested interest in what I have to say about them.
@@Alien_Planetology can you do trantor from foundation?
@@_martian101 There isn't enough astronomical data available for it.
Wait...if it orbits Alpha Centauri...wouldn't it go the way of Trisolaris? You know, getting 3 body problemed and jettisoned/frozen/fried?
Not necessarily. According to modelling of the system, planetary orbits around α Cen A below 2 Astronomical Units should be stable.
Proxima Centauri is pretty far, but is Polyphemus is big enough it could be? Just because A. Centauri B is so close to A. Centauri A
Could you make a video about the world of birrins please?
I am not able to find any astronomical data for that planet.
Can you do 4546B from subnautica?
I would love to! Subnautica is one of my favorite video games of all time. Unfortunately, there is virtually no astronomical data available for the planet, so I can't make a video like this. But I hope to make a video of some kind about it eventually.
Could you grade my planet please? It’s my first attempt at making a planet with its properties listed so expect inaccuracies as I’m terrible at maths
Planet: Darwin Prime
Moons: 1 major moon
Star: 36 Ophiuchi-C
Day length: 30 hrs
Year length: 216 days
Radius: 6,997,381 m
Mean density: 5042 kg/m3
Mass: 7.236007869529 x 10^24
The geophysical realism is excellent (+1). All your math checks out and your planet is well within the realistic mass/size range for a terrestrial planet. You didn't give your planet's surface gravity, but if anyone is interested, it is 9.8636 m/s2 or 1.0044 G.
The orbital realism is good (+1). Given 36 Ophi C's mass of 0.71 M_Sol, your planet's average orbital distance is 9.4034x10^10 m or 0.6286 AU.
You did not provide any data for the climate realism (0). I know you probably haven't gotten that far yet, so consider this score temporary. Based off your planet's distance from its star and the star's luminosity, your planet only receives about 23% as much energy as Earth does. So, as it sits now, your planet is likely to be very cold.
You did not provide enough data for the satellite realism (0). Having only one major moon is quite realistic, but without data about the moon's geophysical or orbital parameters, I can't score its realism. Once again, I'll consider this a temporary score.
Its stellar realism is good (+1). Being a spectral type K5 main-sequence star, 36 Ophiuchi C is a good type of star to choose. However, at between 0.6 and 1.8 billion years old, it's a very young star. So I would consider it unlikely for a planet around it to support anything more than single-cell life.
With a score of +3 points, your planet would get a B-grade. It's missing some important data, but what you have so far is really good. Keep up the great work!
@@Alien_PlanetologyThank you so much! I’ll be sure to provide data for those things and change it to be around an older star, since I want the planet to be tropical what distance and year length would it have to be to be said tropical temperature?
@@Cat-On-Wabdermelon It depends on the luminosity of the star you choose.
You can calculate the orbital distance (in meters) by taking the square root of the star's luminosity (in Watts) divided by 4 times pi times the desired stellar flux (in Watts per square meter).
Earth's stellar flux is equal to 1361 W/m2. If your planet has similar atmospheric and surface properties to Earth, then to get the warmer average temperature you want, you'll need a higher stellar flux value. Perhaps around 1470 W/m2.
Once you have the orbital distance, you can calculate the orbital period of the planet by taking the square root of 4 times pi squared, times your orbital distance cubed, divided by the Gravitational Constant (6.674 x 10^-11) times the mass of your star (in kilograms).
@@Alien_Planetology by chance would Toliman or any other of the ophiuchi stars make a good K star to place Darwin Prime around since you said ophiuchi C was too young
@@Cat-On-Wabdermelon Toliman is a good choice. Or maybe 107 Piscium.
Is anyone looking forward to Avatar: Fire and Ash?
@@thestrangecrisismalachi4121 Of course! It'll be silly and scientifically dubious, but It's sure to be visually stunning and entertaining.
Yes, i can't wait 😄
Awesome episode haha
Are you an engineer or otherwise engaged in scientific duties at the Marshall Space Flight Center, i.e. a NASA employee? Or, are you just a very well-informed, knowledgeable and intelligent hobbyist?
Why does it matter?
@ Why does an ostensible adult have an anime avatar? Surely you know that you intimate to others many negative character traits by utilizing an anime avatar.
It matters in so far as I am interested in him as a human. I’m not challenging him on credentials, rather I am fascinated in his knowledge and wish to understand better whence it springs.
@ old comment got deleted for referencing a certain historical event as to why I refuse to let bad people win and ruin a thing I care about, not anime but this specific image.
@@Dianasaurthemelonlord7777 It seems criminal, on the part of UA-cam, that you can’t reply to me in plain language and reference any thing you wish without being censored. Free speech keep people free.