Well, since you've started to delve into making planets look awesome, I was kind of wondering how many different variations of planets there would be? By that I don't mean Solid vs Gas Giant, I mean like Terra, Frozen, Volcanic, Oceanic etc. and on that same point I'm also assuming planets will greatly vary in distance and such from their stars? (So some will be really close and others will be really far away, this would also help determine what the surface of the planet looks like.)

On another note too will there be moons? And will those moons all be just the standard Selena class moons like in the Earth-Moon system or will there by other types of moons sort of like Io, Europa, and Titan of the Jupiter system?

And this last question is completely unrelated to planets but I figure I may as well throw it in here rather than making a whole new post for it... Binary star systems?

Honestly binary stars isn't really all that big of a deal, but I'm just asking because I know that in real life a good portion of star systems are actually binaries, I'm not sure if implementing this would have any technical difficulties regarding lighting of planets, moons, asteroids, and other objects, but it would be really cool to have binary systems alongside the single star systems. (And on that note... Ternary systems? Now those ones would definitely have some technical difficulties.)

What, no love for CoriW's post?

I'm surprised there's not been more interest in this subject. Presumably we'll be spending plenty of time in space in Limit Theory obliterating with hot electric death anything that moves... but what about those among us (I know you're out there!) who are looking forward to trading and exploration and the more civilized ways of interacting with strangers?

That stuff seems more likely to happen on or near planetary-type bodies, I would think. (And Josh has been talking about planet generation lately.) So I'd like to hear more of people's thoughts about what sort of variation they'd like to see for orbital objects.

As a starting point -- I don't necessarily endorse it as a final answer for a game, but you have to start somewhere -- the Planetary Habitability Laboratory (PHL) maintains a Habitable Exoplanets Catalog. It suggests a Periodic Table of Exoplanets, arranged as a matrix of 18 possible planetary categorizations. It's based on six size/mass categories, from tiny (Mercury-size) rocky worlds to Earth-size planets to "small" and large gas giants, and three distance-from-star categories: Hot, Warm (habitable zone), and Cold.

Here's their categorization of bodies in our Solar System:
(Note that the categorization in this diagram of Venus as a "Warm Terran" world may need to be adjusted to a Hot Terran based on a suggested revision of the habitable zone calculation by Penn State researchers. This new model puts Earth at the inner, hotter, edge of the zone, and Venus well inside it.)

There are two other main ways of coming up with a system for planet type generation:

1. A simple list of planet types. This could be something like "Mercury, Venus, Earth, Mars, cold Venus, hot Mars, gas giant" or have either more or fewer world types. Even simpler might be "rocky hot, rocky temperate, rocky cold, gas giant" with procedurally generated terrain types to match. This approach gets planets dealt with as quickly as possible, allowing more time for other parts of Limit Theory to be developed.

2. A grid similar to the PHL's but using different criteria, such as amount of solar flux received, "daily" temperature range, atmospheric pressure, atmospheric composition, amount of water present, primary mantle composition, and so on. It might be fun to be able to specify water worlds, snowballs, jungle planets, ammoniac oceans, "heavy" worlds, young worlds still burning as they're bombarded with protoplanetary disk debris, high-pressure worlds where humans would have to find mountains to live on, silicon-rich worlds littered with quartz and gems, and a whole host of even more exotic places. These could emerge naturally from a grid showing the intersections among many basic planetary characteristics, and this could be used to determine not only the general look of a world, but some of its gameplay-specific features as well, such as natural resources and the forms of alien life present. This approach allows for more kinds of gameplay related to planetary type, as well as making the whole game much more visually interesting.

I like the "planet types emerge from their multiple characteristics" model for planet generation, myself, but I can see the pros and cons of both systems.

What do you folks think?

There is certainly a lot of potential for a wide range of planets in LT. Just look at some of the artistic renditions of exo planets made by artists working for NASA. There is a lot to work from.

I hope to one day see this kind of thing in a future space game.

Incidentally, the exoplanet count is up considerably from when I posted the previous image:

What happened to the 73 cold Miniterrans in the first diagram?

BFett wrote:What happened to the 73 cold Miniterrans in the first diagram?

The first image is Solar System bodies, the second if Exoplanets.


The cold miniterrans are freaking hard to spot, so wont show up as exoplanets for a good long while.

But I like that the numbers are headding in a direction that suggest that the Sol System is fairly typical.

Means MUCH larger chances to get to xenocide alien life.

Silverware wrote:

BFett wrote:What happened to the 73 cold Miniterrans in the first diagram?

The first image is Solar System bodies, the second if Exoplanets.

Correct. I should have been more clear that these charts described different things -- thanks, Silver.

But the exoplanet count is, as I said, up considerably from when I posted the Solar system count in 2013... and the recent reassessment of the Kepler data added many more as "confirmed," and the reduced K2 mission is still in progress.

I can't even imagine what we'll learn when the Transiting Exoplanet Survey Satellite (TESS) starts returning data.