Alternate Planets, Suns, Stars, and Solar Systems Thread
- Thread starter Pragmatic Progressive
- Start date
4 * pi * r^2
Okay, that's rather too pithy because planets are not necessarily spherical, but it gives the general approach. You figure out the mathematical shape of the planet and then calculate the area that results.
Do you think the description I have for my system on the previous page is somewhat realistic?
The Tava Belt is a rough collection of minuscule asteroids that orbit very close to the star. It's not likely that the belt will survive the next hundred thousand years, as drag from occasional flares, as well as gravitational influences whittle down their velocity.
Aoerba (Follower) is a Mars-sized rocky planet that orbits at an incredible 0.005 AU, and as such is super heated by Tava's light. Nonetheless, Yivarkans (the native species) colonized areas around the poles, where the heat was more bearable. A large impact crater can be found, seemingly formed within the last 13,000 years. Its name comes from the fact that it's never seen far from Tava in the sky, and so early Yivarkans personified it as a follower of the star.
Turen (Dirt/Home, etymologists are split 50/50 ITTL) is the largest rocky planet in the system. 96% the size of earth, with similar gravity, day lengths, air composition, and even temperature, this planet more than any other is a visage of our own planet. (Ignore that it orbits at 0.014 AU, and that the years are 18 days long) The flora on the surface is purple due to retinal being used instead of chlorophyll. The Yivarkans also evolved here, four eyed, four armed humanoids. Unified over the course of centuries under a single religion, their technological advancement eventually led them to unlocking gravitation engines (and therefore spaceflight) at ~1830s technology. This resulted in the slow down of further technological advancements. Yivarkans themselves are split into three major sub-species, with Hesdorians (often called Fennec's due to their short stature and large ears) and Glen'aie (often called Arctics due to their polar environment and albino fur) being oppressed by the larger "Standard" subspecies. The two moons of the planet are binary, and are called "the Dancers" due to their slow, 18 hour rotation in the sky.
The Segne Belt (Neighbor Belt) is the second largest in the system, and holds a variety of objects and bases. The large mineral deposits caused this to be one of the first areas colonized by the Yivarkans. Oddly, no large dwarf planets can be found here, the closest one being Ayos, which now houses several bases.
Opel (Watcher) is the largest planet by far, being 45 times the mass of Earth, and orbiting at 1.49 AU. It has 5 major moons, and 19 minor moons, with other historical ones being mined out in the past. Opel's orange coloration looks like the light orange-tan tint of Yivarkan eyes, thus giving it its name. It's largest moon, Eller (Listener), bears life in the form of methane-based slime molds covering wet, low-elevation areas. Eller gains it's name from a myth in where the major moons (visible from Turen) listened to the giant planet tell stories of what it was watching over.
Causac (Red Light) is the second largest planet, with 13 Earth masses, orbiting at 3.63 AU (In a 1:2 resonance with Opel). Its distinctive burgundy color comes from complex componds in its upper atmosphere. Kinisent, the largest moon, was historically settled to extract water for longer journeys, and still remains settled to this day. Its name comes from the distinct deep red it has in Turen's sky, somewhat resembling their star's light.
Two dwarf planets, Roches and Kess, have irregular orbits between Causac and Sijsiv, and may be flung out of the system after an encounter with the former.
Sijsiv (Dissapointment) is a Mercury sized iceball, pock-marked with craters and canyons. However, this seemingly wasn't enough to the Yivarkans who settled here, who changed its name from El-Eta (Bright Star) upon the discovery of its admittedly mundane surface. The new name stuck, and so the planet is forever known as disappointing. Not good for tourism.
The Nisi-Yeip Belt (Outer Belt/Further-than Belt) marks the end of the system, excluding the Oort cloud. Many dwarf planets and other icy worlds exist out here, none too exciting. Rrivv Ga’p (Gray Stone), Servi (Pink Flower), Nisi-Viver (Far Rock), and the Ethi (Twins) binary dominate this cold, icy expanse.
But even further out, some even scraping the Oort cloud, some colonies are seen. Starbound, New Karelia, and Halfway (settled by the United States, Union of Sovierign States, and European Federation) were colonized by humans as they entered the Tava system during the end of the Centauri-Human War. These outposts represent the final frontier of the Tava system, and nowadays, both Humans and Yivarkans find new bodies to examine and settle.
Thanks for checking this out! If you have any questions, lmk. I'd be happy to answer lore about any body or history ITTL. Have a good one!
(Edit: error with attaching the image)
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What factors would I need for a world of mine to have a rotation of 48 hours yet have a solar insolation similar to that of Earth's?
But wouldn't that expose the planet to the problems typical of 48-hour rotations?
???? If you have a 48 hour rotation you have a 48 hour rotation - the Coriolis force will be weaker, and the temperature will vary more between day and night. (If you were to give the Moon an atmosphere and water, but make no other changes, there would nearly always be storms at sunrise and sunset - while the atmosphere lasted.)
I ask again--What factors would I need for a world of mine to have a rotation of 48 hours yet have a solar insolation similar to that of Earth's?
Being about the same distance away from its star, scaled for the luminosity of the star, as the Earth is from the Sun. Rotation period has nothing to do with insolation because 1) insolation is measured as the amount of solar energy intercepted by the disc of the planet (usually averaged over some period of time) divided by the area of the disc, which clearly has no influence from how fast the planet is rotating 2) because the longer nights and days cancel each other out. A tidally-locked planet with no day or night cycle and one rotating so rapidly it is on the verge of disintegrating will have exactly the same insolation, provided that they are the same scaled distance from their star.
Any planet that is the same distance from the sun as Earth is will have the same solar insolation, no matter how fast or slow it rotates.
https://energyeducation.ca/encyclopedia/Insolation
https://simple.wikipedia.org/wiki/Insolation
No, it won't. Longer days mean hotter days, colder nights and weaker currents if Earth's distance from the sun is unchanged.
Are you sure what you are talking about is the same as the terminology you are using? Are you using a different terminology, a different area of knowledge or starting with a different mother tongue rather than English? None of those things are wrong but they could cause miscommunication.
Solar Insolation uses no time unit beyond the needed for the Watt, which is standard and thus plays no part in the whole of the calculation. If you are asking the for the Solar Insolation per day, then yeah, it would change, but only to be multiplied by two compared to Earth's. If you are asking for the number across a whole year, then it would be the same as a normal year. Unless you are considering a year is still 365,25 days approx., just that said day is still 48 hours instead of 24, then your year would be two revolutions of Earth around the Sun. In that case the Solar Insolation is the same as two normal years.
If you are asking for a formula for the Solar Insulation for a specific area over and specific period of time, then sadly I'll have to inform you that even connecting all the computers of all the users in the forum likely wouldn't be enough to calculate it. You need supercomputers to deal with the chaotic systems that make up climate and atmospheric times. You also too small a sample space: just one planet with (somewhat) decent measurements, Earth.
If you are asking for a formula for the Solar Insulation for anything that isn't the one directly received from space, such as what would be the Solar Insulation in an place, at ground level, then you run into the same problem with the chaotic systems. You'd need to calculate cloud coverages, types of clouds, percentage of water in the air, among a long, long list of factors. Again, you'd need a supercomputer for a decently approximate result (which still would mean it likely wouldn't be reliable over time).
It just occurred to me that your question might be related to orbital mechanics more than climate. "What kind of orbit would give a 48-hour rotation while maintaining similar conditions to Earth?" might be the thing you are looking for. If that's the case, then the it also would depend on the type of Moon or Moons your planet has far more than on the orbit itself if the planet is beyond the heavy influence of the star. Tidal locking isn't something that's either black or white either (see Mercury), so you'd have to calculate to which kind of precision your planet starts experiencing the influence of its Moon(s) enough that the gravity of its parent star is negligible across billions of years. I cannot help you all that much with that though.
Solar insolation is simply how much light reaches the planet, rotation rate has nothing to do with it, so therefor assuming the sun is unchanged, any planet orbiting at the same distance from the sun as Earth does indeed have the same insolation as Earth.
Making the atmosphere thicker will reduce the temperature swings while also shrinking the circulation cells (the longer day increases their size) so that will cancel out some effects. (But not completely, an atmosphere somewhere around 2.6 times as thick would make temperature swings between day and night in continental interiors be roughly the same as on Earth, though temperature swings in oceanic areas will be higher than on Earth, but still less than in continental interiors. Making the atmosphere 5.2 times thicker would make oceanic temperature swings roughly the same as Earth's, while in continental areas it will be less than on Earth. Values taken from a very rough estimate calculation I worked out for my own world.)
Currents will be weaker, but both a thicker atmosphere and a longer day reduce equator-pole temperature differences.
See here for various information on what factors can change planet conditions, including but not limited to day length and atmospheric pressure: https://worldbuildingpasta.blogspot.com/2020/03/an-apple-pie-from-scratch-part-via.html
But the amount of sunlight stays the same, regardless of how fast or slow the planet rotates. This is very well-established physics.
I might use this Donjon procedurally generated world map for my planet, Halycon - as some sort of inspiration. Can someone tell me if such a map would be realistic for a habitable planet?
I might use this Donjon procedurally generated world map for my planet, Halycon - as some sort of inspiration. Can someone tell me if such a map would be realistic for a habitable planet?
If there is a whole lot of ice at the South Pole (much of that mountainous interior) it is a map with a number of interesting possibilities. There would be some massive rivers coming off of that ice, but the interior of the icecap would be like Antarctica - very dry, with old ancient ice.
For further reference, I had someone draw my solar system for me. The planet in question here, is Halycon. The planets and moons are not to scale, but it should give you a general idea of this system.
I imagine that there would be quite a bit of ice in the South pole, perhaps large mountain ranges that obscure areas the size of entire nations, far from prying eyes, for perhaps billions of years.
I've see you posting about this system a bunch on this thread, and I've been meaning to respond. It looks really interesting! I have a bunch of questions!For further reference, I had someone draw my solar system for me. The planet in question here, is Halycon. The planets and moons are not to scale, but it should give you a general idea of this system.
I imagine that there would be quite a bit of ice in the South pole, perhaps large mountain ranges that obscure areas the size of entire nations, far from prying eyes, for perhaps billions of years.
Is there any particular reason you chose to have so many rings? Nearly every planet in your system is described as having a major ring system - even if the graphic somewhat exaggerated them, from your description it seemed like they were all at least somewhere between Uranian and Saturnian. It seems like a lot, considering Earth's system only has a few ring systems, and not many that are bright enough to be that visible. Speaking of rings - it looks like the graphic shows Larceny without rings. Is this intentional? Your writeup mentioned Larceny had:
Has Garshova migrated inward since the formation of the system? 200 K is a fairly high temperature for a gas giant of its size. Volatiles need to be able to solidify outside the frost line to form giant planets, typically, and that would probably be a few dozen degrees colder, indicating to me that the planet may have formed slightly further out and has since migrated in. Admittedly, this is also quite flexible.
Aramo has ammonia oceans? Cool! Is there a chance that some strange life could be hiding in them? I see that you have its average surface temperature at -80ºC, while ammonia melts at -78º. Does this mean there will be relatively large ice caps? What is the crust made of? Is there geologic activity like on Meltdown?
The planet:moon mass ratio of Garshova and Aramo is about 270:1. This is much less than the lowest in our system (Titan:Saturn, ~4000:1). Furthermore, since it seems like all the other moons of Garshova combined have a mass a little less than Aramo, the overall ratio is around 150:1. It's certainly different from our system, but, considering our very small sample size of gas giants, I don't think there's a reason to dismiss it entirely - especially considering all of the interesting results that you might get from it.
This map is interesting. There would be a lot of effects which may or may not be intentional. Tectonically, I'm pretty sure that this is completely impossible on a geologically active planet, but then, you don't necessarily need to care about geologic realism if it's not what you're going for. To be fair, you don't have to care about any realism if it's not what you're going for. Just ask Tolkien.I might use this Donjon procedurally generated world map for my planet, Halycon - as some sort of inspiration. Can someone tell me if such a map would be realistic for a habitable planet?
The most immediate thing is that the land:water ratio is way higher than on Earth (I'm eyeballing it, but it looks like well over 50% land). This, along with the height of the mountains in the center, means there will be huge arid regions. Those cities in the middle of the continent are unlikely, unless some very large bodies of water manage to develop nearby them to moderate the climate (in which case, how does the body of water remain without evaporating?). The entire inland continent will be a high, barren wasteland, with habitation existing along the fringes of the large ocean. Depending on the details of climate, the ice-free corridor shown on the map in the north may or may not exist (it might be frozen over). It might make more sense to rearrange the map to be centered on the ocean, more like "pacific-centered" maps of Earth, since there is probably less going on in the land. That would just entail cutting of a bit from one side and adding it to the other unchanged. The huge mountains extending north from the south pole may lock the world into a permanent ice age, with various consequences. I wonder about the volcanic activity within the mountain range - without knowing about tectonics, it's impossible to say what that might look like.
The inland desert would probably exist no matter what you did to the mountains, to some extent. Deleting them entirely, even, would help somewhat (especially in regions where the prevailing winds blow moisture inland), but at some point it would just be too far from the coast. There's nothing like this on Earth. The middle of this continent looks like it's at least three times farther from the ocean than anywhere on Earth.
I'm realizing that the more I look at it, the more it seems like this map is made from several layered noise functions of varying resolution. This is a good way to produce almost-real-looking maps, so generators like this do it, but the arrangement of landforms can lead to odd things like I've described, which is why the generators aren't always reliable. It's weird how every single coast on the planet is flat (no coastal mountains).
You say you want to take inspiration from it. Well, I think that's a great idea - but I'd recommend modifying it quite a bit first. If you're feeling inspired, you could draw up a tectonic map based on the landforms, and then tweak things to make more geologic sense. If there's a "sea level" slider on the generator you're using, you could also just turn that up a few notches. But it's a good starting point!
Of course, if you want to keep the map as it is, obviously go right ahead. Just be aware of the effects that it will have on your planet's climate (and other general systems), and therefore on its civilizations. (I am assuming that there are humans living here - if it's some other species, a lot of what I said still applies, but it's probably much more flexible).
Overall, the solar system looks really cool! You have a lot of creative ideas with these planets and moons! I wonder what the surface of Aramo looks like.
P.S. If you haven't seen his videos, the Youtube channel Artifexian is a wonderful resource on worldbuilding grounded in science, including astrophysics & astronomy, geology, and climatology (and more).
P.P.S. Unrelatedly, the map of Halcyon looks a little bit like Mars.
@Epsilon Tauri
Larceny should not have had rings originally. Karma should also not have rings, that was something the artist drew in there of their own volition. Karma and Wallace are both satellite planets of Lilith, which is a Y dwarf star.
Garshova's rings are brighter and lager than Saturn's. Leitmotif, Sosa, and Edgelwonk's rings are more visible than say, Uranus or Neptune.
Meltdown, unlike Io has a thick atmosphere consisting of sulfur. It would perhaps have sulfuric acid rain. Meltdown is probably around 1 and a half times the mass of our Moon, I am not sure if I stated an exact figure for it previously. I imagine that Meltdown's volcanoes would probably shoot higher than it's atmosphere? If that would even be possible? Not sure, but it would sound very interesting.
The tides between Maple, Meltdown, and Aramo would probably result in geologic activity on all of them - though Maple would probably equivalent to Callisto, in it that it is out of resonance with the other moons and orbits further than them.
Ironia would be a larger equivalent to Metis, in it of that it orbits fairly close in. Ironia is not host to geologic activity, as it is almost entirely consisted of Iron. Perhaps it was larger in the past, and the mantle and crust were blown off in an impact event to form Garshova's rings? Ironia is about the mass / size of Miranda.
As for the planet: mass Ratio, that is quite interesting. Maple is 10% the mass of Earth. Aramo, we can say is around 95% the mass of Earth. Meltdown would be around...1.8% the mass of Earth? Just rough estimates.
This map, if there is ever another version of it will be heavily modified. The large landmass would exist, somewhat as you see here - but reduced in size a bit to allow for more water. Instead of 50/50 which is more or less like the map shows, it would perhaps be 60% water, 40% land, with some of that land locked up under icecaps. The Southern icecap will be over land, as well as the Northern one (unlike on Earth).
Perhaps in the future, I will have a tectonic map made - though, any future versions of this map will be something that is re-drawn. Perhaps in the near future I will show you something I consider to be more accurate.
Artifexian inspired me with the two suns idea. The eclipsing binary of Valey and Shinespark, eclipsing regularly throughout the day. I wonder how long a day would be on Halycon, anyway, with it orbiting closer to two stars, with a captured Lunar mass Moon?
Halycon's ring system is not visible with the naked eye when seen from the surface. It is a very tenuous, perhaps ancient ring system. Perhaps on extremely clear nights on Halycon, one can catch a glimpse of the ring system. Halycon's moon, Corsica is a captured planet. Perhaps on the scale of hundreds of millions ago, the capture of Corsica lead to the destruction of Halycon's original moons.
Larceny should not have had rings originally. Karma should also not have rings, that was something the artist drew in there of their own volition. Karma and Wallace are both satellite planets of Lilith, which is a Y dwarf star.
Garshova's rings are brighter and lager than Saturn's. Leitmotif, Sosa, and Edgelwonk's rings are more visible than say, Uranus or Neptune.
The temperatures are not something that I would hold too much importance to. I do not know exactly what they would be, as I do not know. It would make sense for Garshova to have migrated inward. Garshova would be in the "inner" solar system, and would be more prominent in Halycon's sky than Jupiter. Perhaps one would be able to see the visual size of it in the sky, as well. Halycon's star system is dimmer, smaller and more closely compacted than our own if I had any guesses.
Aramo would indeed have life on it. Though of what kind, I do not currently know. Aramo's atmosphere, and it's "Water" cycle will be as complex as on Earth. Unlike Titan, the moon is not covered by a thick atmospheric smog. I am not sure what the moon would be consisted of, exactly, though it would have a differentiated core and outer core like our Earth.
Meltdown, unlike Io has a thick atmosphere consisting of sulfur. It would perhaps have sulfuric acid rain. Meltdown is probably around 1 and a half times the mass of our Moon, I am not sure if I stated an exact figure for it previously. I imagine that Meltdown's volcanoes would probably shoot higher than it's atmosphere? If that would even be possible? Not sure, but it would sound very interesting.
The tides between Maple, Meltdown, and Aramo would probably result in geologic activity on all of them - though Maple would probably equivalent to Callisto, in it that it is out of resonance with the other moons and orbits further than them.
Ironia would be a larger equivalent to Metis, in it of that it orbits fairly close in. Ironia is not host to geologic activity, as it is almost entirely consisted of Iron. Perhaps it was larger in the past, and the mantle and crust were blown off in an impact event to form Garshova's rings? Ironia is about the mass / size of Miranda.
As for the planet: mass Ratio, that is quite interesting. Maple is 10% the mass of Earth. Aramo, we can say is around 95% the mass of Earth. Meltdown would be around...1.8% the mass of Earth? Just rough estimates.
I intend to be as realistic as possible. This map is a very broad guideline at most. I'll do my best to answer your comments and questions.
As for this huge amount of mountains, I will say that while I do wish for there to be a huge arid region - it would not be as large as depicted on the map. My goal is for Halycon to generally have a more "diverse" range of landforms than what we see on Earth. With perhaps this huge arid region being contained more towards the center and southern part of this large land mass. I will also say that Halycon is 93% the mass of the Earth. Gravity difference would not be as pronounced as on Mars, but it would possibly result in higher mountains? And perhaps those higher mountains will obscure / cut off a large portion of the Inland from the exterior, possibly resulting in a divergent ecosystem within that is more arid, and adapted to a lower atmospheric pressure.
Yes, this is true. Perhaps we can imagine this landmass is broken up somewhat, but it largely, is what I wish to present. There would be a large area of mountains, leading to a massive continental plateau of some kind in the center, possibly? It would be likely arid, yes, but it may also have a locked up icecap within those mountain ranges that could be the source of many rivers. If it is that large, perhaps Halycon has...3 icecaps, rather than two? Although, I am not at all sure about that, so I don't know. I'm not a geologist.
This map, if there is ever another version of it will be heavily modified. The large landmass would exist, somewhat as you see here - but reduced in size a bit to allow for more water. Instead of 50/50 which is more or less like the map shows, it would perhaps be 60% water, 40% land, with some of that land locked up under icecaps. The Southern icecap will be over land, as well as the Northern one (unlike on Earth).
Perhaps in the future, I will have a tectonic map made - though, any future versions of this map will be something that is re-drawn. Perhaps in the near future I will show you something I consider to be more accurate.
Artifexian inspired me with the two suns idea. The eclipsing binary of Valey and Shinespark, eclipsing regularly throughout the day. I wonder how long a day would be on Halycon, anyway, with it orbiting closer to two stars, with a captured Lunar mass Moon?