Anatomy of a (HABITABLE!) Solar System | Worldbuilding

Episode 7: Worldbuilding Planetary Systems and Moons
In this video we discuss the creation of planets within a solar system, establishing their orbits, determining habitable zones, and looking at why Jupiter is the guardian of our solar system.
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WORLDBUILDING CORNER: www.worldbuildingcorner.com
Solar System Builder: www.worldbuildingcorner.com/r...
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All music, images, and other media used in this video are available for commercial use with Creative Commons licensing, found on www.pixabay.com and www.pexels.com.
Tidal Locking animation credit to Stigmatella Aurantiaca, allowed for use under Creative Commons licensing with attribution: creativecommons.org/licenses/...

[@Fabyskan]

This is so detailed.. really amazing Im just sitting here and thinking about the solar system of my world... even tho my characters will never leave the planet lmao

[@alexanderzippel8809]

Same. The biggest amount of attention anything besides my earth is gonna get is through a single side character who is an astronomer

[@nineblackgoats]

Even if they don't, astronomical phenomena, visible moons and planets etc can have interesting cultural implications.

[@Fabyskan]

@@nineblackgoats A really good point. I actually didnt think about that

[@Rei_geDo]

I also happen to be building a binary star system and a planet with two moons, so I'm really excited to see how this shapes out, as it's the first I've seen so far that has both two Suns and moons. This channel is a worldbuilding godsend!

[@WorldbuildingCorner]

Thank you! I wanted to create a system that is plausible but still unique and interesting by our standards as earth-dwellers haha. Plus there's an element of the balance between two stars, two moons that I really like and I think gives great worldbuilding potential for cultures down the line. Good luck with your own worldbuilding project!

[@Rei_geDo]

@@WorldbuildingCorner The balance of two binaries and potential for cultures is exactly what crosses through my mind when creating my project too. I also have to say that your spreadsheet has helped me a ton in better visualizing my system, so many thanks for that and props on how well done it is!

[@WorldbuildingCorner]

@@Rei_geDo You're very welcome, glad the resource is useful!

[@andresmarrero8666]

I think an ethereal green color would have worked as well given that you already have a red dwarf as a star.

[@eryscalamitas1611]

I'm binging this series because it seems very interesting and the suns already gave me ideas, but the moons? tripled those ideas. This is a fantastic series and I love it

[@vincentcleaver1925]

I'm interested in the mechanism which gets locus into a stable orbit; I imagine it has everything to do with the binary and vigil, but it blows my mind!

[@Shukaldes]

Habitable zone matters for exposed life but there are some species that can exist and thrive under huge ice sheets.

[@gaelicpatriot3604]

Malus isn’t really a minor moon, it’s a small major moon. It’s radius is 1012km. Minor moons are supposed to have a radius

[@JimWeaving-ty6tr]

I absolutely love your dedication to using real science to guide creativity and realism! As a scientist myself, it's exactly the approach that I want to take in building my own world, so you're provided some very useful stuff here. Thanks mate!

[@Shalashalska]

Wouldn't the high eccentricity of Locus cause it to have significant temperature variation across the year? It would get 50% more solar radiation at 1.2AU than at 1.5AU.

[@ultramark2o959]

It'd be cool if Malus was so close to the planet that each year it was closer and closer, so that it would eventually collide with Locus. It would suit the name

[@kiwiworldbuilder6449]

I have been doing a lot of this detailing in my world(building), since the Covid lockdowns. Your work on the "science of it" has helped me add the sauce on those meat and potatoes. Cheers

[@jehooft8569]

But... How did Locus get these moons? Were they formed along with Locus, traveling with it to the new solar system, or did Locus crash into an already existing protoplanet in the new solar system Theia-style? Or did it just capture the existing protoplanet? I'm curious

[@Tsurf]

It could have snagged them from any of the outer Gas Giants on the way in too.

[@AW-wf2dx]

This was a useful vid.

[@WorldbuildingCorner]

Thank you, glad you found it helpful!

[@khilorn]

I agree

[@cerberaodollam]

"I'm not lonely, I have 13 cats!...er, moons."

[@tristanmitchell1242]

What about if you wanted the habitable planets to themselves be moons of a gas giant? Like, imagine if you had like three habitable moons orbiting the gas giant, which itself orbited a binary star system. The habitable moons get called "Home", "Brother", and "Sister", but you could have two cultures that argue over what the Gas Giant and suns are called. The larger sun is always called "Father", but in one culture the planet is "Mother" and the smaller sun is "Mistress", while the other culture calls the smaller sun "Mother" and the planet "Nanny".

[@foofy8977]

Yeah, I would like to onow about habitable moons and how to make them to. Honestly its very hard to get any useful info on that from the net

[@phoens2803]

2:55 I'm strugling with how did you find the rotation speed? Did you just randomly chose it or is there any equation? And I wanted to say that your work is amazing, it really helps me to build my world and to organize or find ideas!

[@lordeludrian1418]

Your videos are incredibly well done and inspiring. Have already made a world for a game and hadn’t intended on doing the full scientific break down, especially with high magic involved…but now I’m convinced to do some backwards building and make it all work. Lol Now I just have to figure out how a terrestrial planet only a little larger than Earth garnered five moons, one primary like our own and the other four only appearing one at a time alongside the primary during the length of each season. This should prove interesting. Especially since I want to try not to do the “because gods said so” if possible. :P

[@midzyblinkonce7716]

For a terrestrial planet to have 5 moons, it could have at one point been a planet within an asteroid field perhaps. As asteroids collide and get larger they pull more in. Large enough to form a planet, some smaller asteroids start orbiting the planet and crashing into each other to form moons perhaps. Or a planet with rings around it like Saturn, and the moons formed from them.

[@lordeludrian1418]

@@midzyblinkonce7716 Some very good ideas there! Thank you for the suggestions, I'll definitely have to consider them. Given I hadn't considered the world having rings, its more likely the asteroid field hypothesis. Hm...*ponders thoughtfully*

[@WorldbuildingCorner]

That sounds like a very interesting project! In addition to Midzy's excellent ideas, you also have the advantage of a high magic world using magic to literally place the moons in orbit. I know you mentioned you don't want deities involved, but any exceptionally powerful magic user could do the trick. If it's high magic enough, maybe the moon ITSELF is a magical entity, responsible for its 'children'. You could even realistically place the minor moons within the hill sphere of the major moon and have it all work soundly. And thank you for the positive feedback, I am glad you have found the series inspiring so far!

[@lordeludrian1418]

Very good ideas as usual from you as well! Jotting down plenty of ideas already thanks to you two. 👍🏻 Matthew, please keep up the great work! And thanks again Midzy!

[@user-mt1qi4vd1z]

Anyhow, it wont be stable at the geological timescale. But stable period can be long enough

[@logicisuseful]

I’m curious to know if you know a way to figure out what would happen if the planets in a binary system had “circumpolar” orbits (ie, orbiting perpendicular to the orbital plane of the two actual stars). I’ve only ever seen minimal information on the topic, the gist being “possible, and possibly technically habitable, but the weather would be *insane*”).

[@SneakyTogedemaru]

2:40 - just how severe of a seasonal temperature difference we'll see with this much difference between minimum and maximum distances from star(delta seemed too big to me, so I checked Earth's delta, and it is only 0.034)? I'm not sure how much it'll affect temperature really, but if we have a delta of 0.296 AU I'd imagine that might cause great seasonal variation. Since they stay in habitable zone, I can believe for life to adapt to it, but it seems to me it'll have to have a great effect on your future intelligent species...

[@GentlemensClubHolyEdition]

Is it possible to get a habitable moon working?

[@Nerdgirl9853]

7:18 I want to point out this part is just blantently incorrect. It is a misunderstanding of the Titus-Bode Law. What you actually do is find the innermost planet's semi-major axis, multiply it by ten, and then continiously multiply by 2 to find stable orbits. (Dividing each value by ten to convert it back to standard AU), this finds approximated orbits for planets. But falls off as it gets further out into the system, as it tends to get overly high numbers for further out planets. For instance, for the Solar system, it predicts 0.7, 1, 1.6, 2.8, 5.2, 10, 20, before it begins falling off, getting 39 and 77. Outside of those two, all but 2.8 is very close to the actual orbit of the planets. But that is just due to the fact 2.8 is one of the *potential* stable orbits. It isn't perfect, and other better formulations do exist (as mentioned before). Looking at the Titus-Bode Law page on Wikipedia for further details and links to sources on the subject. It does not rely on starting with a gas giant, and it is not based on factors of 1.5. i also tried your method with out system, and got very wrong answers. It only approximated Earth and Mars, and everything else was very off, it also required a very large number if interations compared to the other method. It also failed to approximate any planets beyond Jupiter. I apologize for my aggression, I just dislike when misinformation is spread without even saying what your basis is for the math, or any citation/further reading on the topic. I suggest in future videos you better cite where you get your information from, and mention the theories/laws you are using for your rationale. It helps a lot to verify information and to read more into the sources used. : ) Just want to see you get better and grow. And part of that is learning to do better research, and better site your sources.

[@squessi]

LOVE your series! watched it some months back and i've come back to it now that I have more time to do my own worldbuilding. I do have a question though! and maybe this just comes from me not understanding something in the spreadsheet. I am having some trouble with the surface area measurements particularly... If you place a planet of 1 earth radius and 1 earth mass it will calculate the surface area as 12.566, what is this 12.566 relative to? Surely it cannot mean 12.566x earths surface area as that does not make sense for an earth equivalent planet. Am I misunderstanding the radius measurement, or the final output? EDIT 1: I spent some time trying to properly think it through - and I believe that means 12.566 Square Earth Radii. So to get the number of square km it would be 12.566 * 6378^2 Where 6378 is the radius of earth. Is this a correct assesment?

[@user-uu5rp1pw2x]

Since the two moons move independtly of eachother dies that that mean you'll see them near each other or far from each other when looking in the night sky?

[@ericdutton6743]

In my worldbuilding I have 1 major moon that orbits the habitable planet. I envisioned it being a light purple and silvery colored moon with a thin ring or rings around it. It is a fantasy worldbuilding project, but I was curious as to what it would require (if even possible) for it to actually be a possibility within our known universe. There is only 1 star in the system.

[@epicspacetroll1399]

If the moon has habitable conditions, purple color could come from photosynthetic archaea. It's hypothesized that 3.5-2.4 billion years ago the first photosynthetic organisms used a chemistry that made them purple instead of green. As for a ring system, I'm unsure on how to get that. The moon would probably need to be orbiting fairly far away from its parent, be very smooth, and have had some event occur recently to have produced the rings. Our own Moon has a fairly lumpy gravitational field, so between that and the small, but noticable pulls of the Earth and Sun, most orbits around it are unstable on timescales of just years to decades. There are certain "frozen" orbits that can be sustained for longer periods, but still probably not enough to sustain a ring system for geological time periods. Idk, I'm not an astrophysicist, just interested in these topics.

[@j.f.fisher5318]

It would be interesting when someone invents a pinhole projector. Especially if what they see makes them a heretic.

[@herrbrennholz977]

When I try to enter the calculation formula for the average surface temperature into my calculator, the result is about 40 degrees Celsius too high. even if I use the same numbers as in the video.

[@BigBrain05]

Jupiter is not the guardian it is the menace

[@adamjenkins7653]

Soo... I mentioned back at the start of the playlist that my world building project was based or at least themed on an MMO. This removes some freedoms regarding year length, and all the associated details. In short, if I want to have seasonal events like a xmass event in the appropriate season, I need a year length as close to Earths as possible. So I plan to just match it. I am free to play with day length, so I plan to increase the relative speed so that 2 days pass on that planet compared to every earth day. Ordinarily I would factor this back into the worldbuilding, but here I won't. Should the project be completed and used for the purpose of a game the day length will largely be calculated on how it would serve the player, as opposed to how realistic it would be. All that however leaves me with a minor issue. As mentioned in #2 in the series "The rules of PHYSICS" this universe has a psuedo-energy called mana. Stars and planets with a molten, free-moving/rotating core generate mana. one of the abilities of mana is to increase the heat of local matter. So my star and planet are hotter than normal, and the only way to feasibly cool them is to add mana-insulators like gold. That's fine on my Earth-like unnamed world, but stars IRL don't generate materials past Iron during their lifetime. Materials past that point on the periodic table are generated by supernovae. Largely due to the energy requirements... but with enough mana a Sol sized star might be capable of doing so. As a result here I am going to ignore certain details. They would matter if I was to have my peoples leave their home world but they are largely in the "Medieval period" so I will take my novel approach here: "Go 1 size bigger than what you show", meaning I should have a good idea of the details around the location I'm focusing on. As I don't leave my main planet I don't need to go too detailed on the local system. Enough or Galileo to look at and make some theories, but not space age detail. So Earth sized main planet, Sol sized star, local primary will be running hotter than base physics would indicate, as would planets with a molten core. As a result I will have more storms and more dramatic weather systems (Stuff I will need to think on as that would effect both the map, and the ecology, along with the gameplay) and less surface ice unless I rework some of the rules of mana. Edit 1: As for celestial neighbours we have our gas giants: "Watchman" an Azure blue gas giant a about the same orbit of your "Vigil", and "The Dark Hound" A dark blue gas giant in the outer system. "The Dark Hound" is an extra-solar capture and is orbiting counter to the other planets, but due to it's proximity it is pulling "Watchman" slightly out of orbit with each pass, though the star will die before that becomes a major issue. Then we have "Death's pendulum" a pale planet close to the star that is periodically obscured by one of the twin planets commonly referred to as "The Arms" in the scholarly circles. These 2 actually have the same orbital path and orbit between our earthlike and "Death's Pendulum" as for why that normally poor idea is somehow stable, they are at opposing ends of their orbit and perpetually chase each other. Past the Earth-like we have "Times Watch" a grey lifeless planet, and just past the belt is "The old Garden" Note: these are the translations of the Human Imperial names for the planets, as most Kobolds on the main continent have basically been beaten into obscure, dangerous locations or have yet to be in contact with the largest Human nation of the northern Hemisphere. As for the names they are all religious in origin (more on that later). They're not nailed down, but I can do that some other time.

[@phiinblade2293]

I know this is an Old video, but Im hoping you'll see this. Im trying to create this system in Universe sandbox, but rufus keeps ejecting any planets that i attempt to place anywhere near the stars

[@fatesend8637]

I've been trying to figure out habitable zone size as it relates to star size. Does anyone know this?

[@sijul6483]

If you haven't already, I found the size for mine by looking up "habitable zone of a (your star classification) star" got an article from Wikipedia. Alternatively, check out the video about stars on his channel.

[@Chaosmech]

You could calculate solar energy that Earth receives and then by determining your star's energy output and the size of your planet, you could ballpark a habitable zone yourself

[@derskalde4973]

So, is there a site where you can make all the math and see how such stuff affects a world? Cause I work on a world with mostly two moons. It has two constant moons, as well as a rouge moon on a more or less elliptical orbit, that "visits" the world every few years, which causes most inhabitants to view it as evil. One culture uses a moon calendar based on this rouge moon, so they meassure one year from this moon getting visible in the sky until it next gets visible, causing one of their years to be several years for most other cultures. I know that this would obviously have consequences for that world, but I am unable to figure out what and how big these would be realistically.

[@hanzzel6086]

Culturally, idk. But that culture kinda reminds me of a lot of Indigenous South American "cyclical time" beliefs. Geologically, it depends on the size and distance/orbit of the moon. If it is small enough and stays far enough away, its impact might be negligible in comparison to the other two moons. A larger/closer moon might cause things like unusually (potentially extremely, depending on it's orbital relation to the other moons) high tides (leading to a lot of flooding worldwide, which would help it obtain a reputation of being "evil"). But in that case, it might destabilize the orbits of the other two (but them being particularly large and/or far away would mitigate that risk. So would putting it in a non- planetary disk aligned orbit, which would really mess with the tides). There is also the chance for some really strange eclipses.

[@LewisPulsipher]

I prefer believable worlds, but by going all the way with your calculations, you remove what I'll call Romantic possibilities. One large moon only on your major world, no more, no less, is an example. Yeah two large moons might destabilize your planet in undesirable ways, scientifically, but it might be good for your fiction.

[@LewisPulsipher]

While this is an interesting exercise in mental gymnastics, for game and even fiction purposes it is wasting time on too much detail that is irrelevant. While I don't agree entirely with him, M. John Harrison represents an extreme of this point of view: "Every moment of a science fiction story must represent the triumph of writing over worldbuilding. Worldbuilding is dull. Worldbuilding literalises the urge to invent. Worldbuilding gives an unnecessary permission for acts of writing (indeed, for acts of reading). Worldbuilding numbs the reader’s ability to fulfil their part of the bargain, because it believes that it has to do everything around here if anything is going to get done. Above all, worldbuilding is not technically necessary. It is the great clomping foot of nerdism. It is the attempt to exhaustively survey a place that isn’t there. A good writer would never try to do that, even with a place that is there. It isn’t possible, & if it was the results wouldn’t be readable: they would constitute not a book but the biggest library ever built, a hallowed place of dedication & lifelong study. This gives us a clue to the psychological type of the worldbuilder & the worldbuilder’s victim, & makes us very afraid.” M. John Harrison (author of over 20 novels)

[@Fuar11]

You can worldbuild for the sake of worldbuilding. If you want to write a story you can still worldbuild. If you want to solely worldbuild go ahead. But if you want to solely write a story, worldbuilding to this scale isn't necessary. But it is not wasting time if you simply wish to do it for your own sake. Some people appreciate it