Hey Veeky Forums. I know that when it comes to tabletop games, Fantasy is king. Even the majority of science fiction and horror games still have a lot of influence if not outright mimicking fantasy concepts. World building on Veeky Forums tends to be more or less the same - often a terrestrial world - often limited to a single island or land mass, with a few commonly seen biome types.
However, after trying out the solar system generation rules in Battletech's Campaign Operations and the RPG component, I realise how little I know about things when it comes to space. Like for example, Our sky is generally blue, and mars has a generally red looking sky, and the clouds of Venus have a yellowish appearance, but I have no idea how one might determine based on atmosphere chemical content alone how the appearance of the sky would change, or if there was a world very earth-like but with some degree of chemical taint to the air, how much taint would there have to be before it stops looking like our own sky? Could we technically survive on a world where the atmosphere is not mostly nitrogen so long as the Oxygen ratio is roughly the same? Does a lake of Ammonia look visibly different from a lake of water in any way? How does the landscape of a high-gravity world and a low gravity world differ? How about a planet that is otherwise earth like but due to a bigger size or density has more atmosphere, does it appear brighter and whiter? What would plants evolve to look like under the light of a red star, or a blue one?
Basically, I'm trying to find ways to set up worlds made with this sort of reality-rooted, but still very much non-terrestrial solar system generator to be interesting and believable. Something that isn't simply "another desert planet".
>often a terrestrial world - often limited to a single island or land mass, with a few commonly seen biome types. Because that's what you need for a fantasy game.
For the hard sci-fi setting I'm building, worlds will be more differentiated, and mostly uninhabitable without habitats. Or they'll be space habitat 'worlds'.
Hunter Brown
>Because that's what you need for a fantasy game. Well, yeah. I'm not knocking it. It works for fantasy very well, but that's pretty much all that that we talk about on Veeky Forums or I can find support for outside of the rulebook I'm using. It's like how I can't call phillips-head screwdrivers shit, but if what I need is a wrench, I need to ask for a wrench.
The other issue is that with 40K, Star Wars, and other intentionally soft sci-fi series, handwavium is pretty well accepted and worrying about accuracy is less of an issue, but again, the above two also take up a huge share of the Sci-fi market, leaving even less support for the harder-scifi side of things. Although Battletech is by no means hard sci-fi, the tone it sets tends towards it.
I'm not sure if I should be taking these questions to Veeky Forums, or if Veeky Forums can offer solid support.
Ryder Hernandez
>sky colo Depends on a lot of factors professional astronomers spend their careers studying, don't worry if it doesn't seem easy. Mars' atmosphere would be black if it didn't have extensive amounts of airborne iron oxide dust. Thick atmospheres can be deep blue like Uranus and Neptune; the color is caused by 2.3% of methane in the lower atmosphere. White atmospheres will not be common. en.wikipedia.org/wiki/Extraterrestrial_skies
>Could we technically survive on a world where the atmosphere is not mostly nitrogen? Yes, the important part is the partial pressure of a specific gas; all gases but helium can cause narcosis in high enough pressures. The best gas mix to breathe is Heliox, a mixture of helium and oxygen used in diving and medicine. I'd say that generally a thinner rather than a thicker atmosphere is good for Humans (above the Armstrong limit), especially if the population is descended for people living at high altitudes. en.wikipedia.org/wiki/Nitrogen_narcosis
>lakes Look pretty much like water. Liquid ammonia is clear, but the planet's atmosphere could give it a widly different color. Waves depend on air currents, probably quite measly on planets cold enough for liquid ammonia, and gravity. Hydrocarbon waves on Titan are mere millimeters high, but any splashes while swimming would be pretty impressive.
>surface gravity Higher surface gravity generally means flatter landforms. There's debate whether super-Earths would have more or less active tectonics. Venus is quite boring apart from a couple of highlands (the planet experiences no true plate tectonics, merely periodic resurfacing events), and despite the height of Olympus Mons on the geologically quite dead Mars, it's unimpressive when viewed from the nearby surface, due it its gentle slope. Faster moving plates would tend to form prettier mountain ranges.
Here's the most realistic planet generator I've seen; GURPS Space also has a pretty good one.
>, I realise how little I know about things when it comes to space. Like for example, Our sky is generally blue, and mars has a generally red looking sky,
No you don't realise how little you know.
Mars' sky is yellow.
Ethan Lee
You could crack Eclipse Phase, the Gatecrashing book. It's a quick look at the primarily social aspects of the extrasolar colonies, but there are a number of good ideas in there that are reasonably hard science.
Gabriel Campbell
Download Space Engine for easy random planets with atmospheric composition and shit
Hudson Nelson
Which depends on time of the day, atmosphere, angle of the sun, weather and other factors.
After all earths sky can go from dark grey to blue to pink. Also black with white spots and green waves.
Lucas Carter
Waves also depend on lunar influence user.
Ryder Torres
GURPS Transhuman space is a great setting, so is Eclipse Phase.
Isaac King
Those are tides, user.
Gavin Hernandez
Related. Using GURPS: Space, I was having a great time generating systems until it came time to place planets in the orbits of Binary systems. That was so very confusingly written.
Brandon Jenkins
The average planet created by the Mongoose Traveller planet generator is an inhospitable rock if you use the hard sci-fi rules.
Nolan Ross
Hard sci-fi rules?
Ryder Gray
Are hills and forests natural borders for nations?
Jason Thomas
Likewise with Battletech's. In fact, you're usually just lucky to have a planet that has a gravity that is hospitable, never mind breathable atmosphere. They are good enough to include a "habitable" column on the star chart to boost hospitable stars' chances from the get go, considering the life zone is usually only one or two orbits' worth.
I bookmarked the shit out of this post. Thank you for the insight.
Jordan Price
The rule about forbidden zones around binary stars? It's basically just saying that either the stars need to be close together and the planets orbiting both of them further away (a Tatoiine situation), or the stars will be dozens or hundreds of AUs apart, each with their own planetary system. Other kinds of planetary orbits would be too unstable due to the other star's gravitational influence. For example, Alpha Centauri A and B have a minimum separation of 11.4 AU, so using the GURPS rule, they can only have planets within 3.8 AU (the inner edge of the forbidden zone). Actual studies estimate that stable orbits exits within 4 AU for planets that orbit on the same plane as the two stars, so it's a good approximation. The GURPS rule also gives us an outer edge of the forbidden zone (100+ AU due to the maximum separation of about 36AU) beyond which orbits are once again stable, but they'll be iceballs similar to our Kuiper belt objects, and they orbit the center of mass of the AB system.
>40K, Star Wars Science Fantasy and Space Opera respectively. Not really sci-fi as such.
Samuel Kelly
Any anons able to give me a hand with a tidally-locked world? I initially started developing one based on the 'eyeball' pattern like pic related but now I'm hearing that the heat map might not work out quite like that. Really having difficulty parsing the contradicting theories on the matter. Would there be a 'hot side' and a 'cool side'? Or would it end up being lukewarm with crazy high winds? I've heard both.
It's not a terribly incorrect map. There would be a hot side and a cool side, but you couldn't have a wind blowing forever. The pressure would eventually drop too far and the flow would stop.
What I would assume is that the dark side of the planet would be mostly ice, with glacial creep. You'd have a ring of water, and as that got further out it'd evaporate and flow back to the cold side, falling as rain and refreezing. I think things would actually be quite stable, wind and weather wise. There might even be near-permanent rain clouds in patches, with constant flow. The other possibility is that there would be patches of harsh correction, depending on how stable the orbit is. It might wobble a bit, so you'd occasionally have the temperature 'hot zone' moving around the planet a bit and causing temporary super storms as things reworked themselves.
Without a day/night cycle life would be radically different.
