Changing Planet Creation Rules to Reflect Realism

[TGLS]

Originally Posted by Stone Dog

Nobody could ever really explain well enough why Pluto was a planet and nothing else that big was.

If I remember correctly, they thought Pluto was much bigger when they discovered it. It shrank from 1 Earth, down to less than 1/450th Earth by today.

[AlexanderHowl]

I disagree that moonlets are unimportant. You are talking about objects that can be as large as large asteroids like Vesta, so they can potentially possess hundreds of trillions of dollars worth of materials (if not more). Even they smaller ones can be valuable if they possess the right materials in the right place (for example, Deimos and Phobos might be 60% ice, which would make them the cheapest source of hydrogen in the Inner Solar System).

[David Johnston2]

Originally Posted by AlexanderHowl

I disagree that moonlets are unimportant. You are talking about objects that can be as large as large asteroids like Vesta, so they can potentially possess hundreds of trillions of dollars worth of materials (if not more). .

<shrug> There are asteroids all over any normal solar system. Doesn't mean we have to count them all.

[Flyndaran]

It's not that they're always unimportant. It's that they're not always important.
They're common and small enough to only matter if the GM specifically calls them out as being so.
That's what I mean at least for why I think system creation rules shouldn't spell out how many every single planet may or may not have.

It would be like creating a rule set to map every single mountain in a 100,000 square mile zone.

[PTTG]

I gotta agree with Flyn, in fact I assumed that somewhere in Space it had a line like, "For any gas giant, it should have (mass)*3d6*(scaling factor) moonlets in addition to terrestrial moons" or something. Obviously the numbers could be tweaked...

Let's really not get into the planet debate. I'm trying really hard not to put in my two cents here as well, but really that's not the point of this thread.

That said exoplanet science is rapidly developing. Couldn't hurt to take another look at the way star systems develop now that we have so much more data. Or maybe we can wait until Kepler starts looking at atmospheres, first.

It'd be nice if we could figure out how volatiles really are distributed. It just seems unlikely to me that Earth would have continents despite the fact that most of the garden planets should have mega-oceans going by out current observations. Admittedly they are biased to super-earths, but still.

[AlexanderHowl]

Hm, as far as I know there is no confirmation of exoplanet oceans...anyway, I do agree that the Sol System looks quite particular compared to everywhere else. For example, we seem to have much less mass in our planets than other star systems, with our gas giants and terrestrial planets being rather small by comparison, with some star systems having 30x as much planetary mass.

[johndallman]

Our detection methods for exoplanets have biases towards high-mass ones. We don't really know enough to say if our system is genuinely atypical.

[PTTG]

Originally Posted by AlexanderHowl

Hm, as far as I know there is no confirmation of exoplanet oceans...anyway, I do agree that the Sol System looks quite particular compared to everywhere else. For example, we seem to have much less mass in our planets than other star systems, with our gas giants and terrestrial planets being rather small by comparison, with some star systems having 30x as much planetary mass.

Originally Posted by johndallman

Our detection methods for exoplanets have biases towards high-mass ones. We don't really know enough to say if our system is genuinely atypical.

Yep. And high-mass planets have dramatically higher volatile budgets, so they have far more water.

[Flyndaran]

We can't know that without at least knowing of one other planet with oceans.
As far as we know that sounds reasonable. But at the moment, there's still argument about where Earth's water all came from.

[Rupert]

Originally Posted by Flyndaran

We can't know that without at least knowing of one other planet with oceans.
As far as we know that sounds reasonable. But at the moment, there's still argument about where Earth's water all came from.

Well, if Venus had more water and less CO2 in its early history it'd have had large oceans too, so maybe a better question is why Earth kept enough water to stay warm and wet without ending up cold and dry like Mars or hot and dry like Venus.

Was it a rare occurrence of position and having/gaining a large moon? Or was it a quite common event of no particular note, and many stellar systems have similar planets? Or is it somewhere in between.

The impression I've been getting from recent discoveries is that systems for generating stellar systems for games that are quite deterministic (take a few factors like star mass and age, roll a few dice, and everything flows from that) are likely to be wrong far than ones that rolls lots of dice for everything, simply because what we're seeing is more variable than our older models allowed.

IMO if a planet if physically possible, somewhere in the galaxy circumstances will have allowed it to happen, or something very close to it. There are so mnay stars out there there's room for pretty much everything that's even a little bit possible, however unlikely it might be.

I, for one, am glad it's that way, and hope to live to find out about more of the wonders that are out there.