Help and advice about two fictional planets

[ClearDragon]

I've been trying to create two planets for my fictional solar system. Actually three, but I'm focusing on just two for now.
I wanted a jungle planet where it doesn't get cold even at the poles, but also is not too hot for humans, even if its at the limit.
My idea for this planet is a higher amount of greenhouse gasses and also a single supercontinent with a number of inland seas. Does that make any sense? Would that keep the planet tropical?

The second planet is to be a desert planet. But I don't want a Sahara desert planet like in star wars. I want it to be more like the Sonoran desert, where there are small trees, giant cactus and such.
My idea is a lot less water, maybe no real oceans, only seas on a planet spanning continent. There should be rivers and lakes I think too. Basically I want the climate zones of Arizona and Sonora spanning a planet. Does that make sense?
I'll be back online tomorrow morning.

 

[pmmg]

Well, I love thinking on planets...

Second planet first.

The only reason a planet with land masses and water has oceans and land is that the land is above or below the waterline, which has a lot to do with how hot core of the planet is in pushing water up. On a planet with the waterline below surface level, all (or...most) of the water would be underground. If that planet had craters from impacts, the craters would likely be filled with water. If the land had low areas, they could also form seas and oceans and such. If there was a powerful impact, the planet may not be a smooth ball, and some land is pushed above the water level and some isn't. If the water was ever on the surface and slowly sank, the land would be cut into river beds and high lands, as water would erode it and cut low areas into it.

If we were to slowly raise the water level on Mars, it would start to look like you describe.

Mars with oceans. The land area goes around the entire planet.



For the first...this is less likely, I think, but no one can say it could never happen. If it is just a single continent, that would seem more feasible. The reason being planet tilt which creates such zones in the first place. I don't think there is a way to have to planet spin such that all areas get equal heat (maybe its north-south was exactly a right angle to the planet). If the planet had any tilt, some areas would be hotter than others and cause good conditions in some areas and poor ones in others. But, if there was just one land mass and it happened to be in the zone where the conditions were best for jungle, then jungle it would most likely be.

 

[ThinkerX]

I've been trying to create two planets for my fictional solar system. Actually three, but I'm focusing on just two for now.
I wanted a jungle planet where it doesn't get cold even at the poles, but also is not too hot for humans, even if its at the limit.
My idea for this planet is a higher amount of greenhouse gasses and also a single supercontinent with a number of inland seas. Does that make any sense? Would that keep the planet tropical?

The second planet is to be a desert planet. But I don't want a Sahara desert planet like in star wars. I want it to be more like the Sonoran desert, where there are small trees, giant cactus and such.
My idea is a lot less water, maybe no real oceans, only seas on a planet spanning continent. There should be rivers and lakes I think too. Basically I want the climate zones of Arizona and Sonora spanning a planet. Does that make sense?
I'll be back online tomorrow morning.

I have to concur with pmmg on this one.

I will even go one step further with this question:

'Are two planets really necessary?'

Both of the worlds you describe are 'tropical' to 'warm temperate.' Planets are *big* - one of my gripes with most fantasy world maps is they typically show only a small portion of the whole planet - and much of the time it seems the authors are not aware of this. Back when I was doing substantial worldbuilding, I ended up combining multiple 'worlds' - simply reassigned those sections to different regions of the already existing worlds. This knocked something like eight or ten worlds down to just two. Since then, I've added two more, but one of those was a do-over of a concept that didn't really go anywhere.

 

[Luís Santana]

a do-over of a concept that didn't really go anywhere.

Why?

 

[Prince of Spires]

Single climate planets in my mind never make any sense. Even here in the Netherlands, which is a country something like 250 by 400 km there is slight climatic differences between the coast and the interior. Increas that by a factor 10 to 100, add elevation differences, mountain ranges, water sources and the like, and there's no sense at all. Already just the fact that you've got a sphere means that places at the poles are cooler than at the equator, simply because the light from the star will be more concentrated at the equator than at the poles.

Now, the fact that they don't make sense doesn't mean they can't work. I think George Lucas showed that you can have single environment planets that everyone loves. The main reason I think it works for him is that he doesn't try to justify it. The story isn't about that. It's about the adventures of a boy, about space magic, not about the worlds.

So if you want them, go with it and have fun. Just don't try to make sense of it.

And consider ThinkerX 's suggestion of combining the two. Why does it have to be two planets?

 

[ThinkerX]

Why?

The original concept was something I didn't need at the time. It was for a science fiction setting and brought with it so many issues I couldn't connect it with the others. I was able to reuse it for 'Empire: Spiral' - slated for release early next year.

The concept is this: a planet dominated by a desert plateau with a very thin, essentially unbreathable atmosphere. Scattered about this planet are a number of large craters or basins (I only developed the one), kind of sort of connected by deep chasms (I was thinking the Marianus Valley on Mars). These basins and valleys check in at two miles deep - or better, with still thin but breathable air - think Earth at about 12,000 feet or a tad under three kilometers. The Alar Basin - the one I developed - is maybe a thousand miles across with a couple large lakes in the middle. One of these lakes is the home/prison of a gargantuan monster/demon/god, dwelling in a 'deep spot' beside a island city of bizarre aspect. The spawn of this entity (kind of sort of giant squid) roam the lakes. Small cities populated by different races - some utterly alien - dot the coasts of these lakes, existing in a stressed symbiotic relationship with the spawn.

There are portals to other planets - the monster/demon/god makes use of one when it's feeling hungry...but they are also hazardous to use.

 

[ThinkerX]

Single climate planets in my mind never make any sense. Even here in the Netherlands, which is a country something like 250 by 400 km there is slight climatic differences between the coast and the interior. Increas that by a factor 10 to 100, add elevation differences, mountain ranges, water sources and the like, and there's no sense at all. Already just the fact that you've got a sphere means that places at the poles are cooler than at the equator, simply because the light from the star will be more concentrated at the equator than at the poles.

Now, the fact that they don't make sense doesn't mean they can't work. I think George Lucas showed that you can have single environment planets that everyone loves. The main reason I think it works for him is that he doesn't try to justify it. The story isn't about that. It's about the adventures of a boy, about space magic, not about the worlds.

So if you want them, go with it and have fun. Just don't try to make sense of it.

And consider ThinkerX 's suggestion of combining the two. Why does it have to be two planets?

Well, some of the new exo-planets discovered probably do have a single climate zone, though they are the opposite of what the OP is after - ice worlds. It is just barely possible some of these worlds might have breathable atmospheres, but because they orbit at the outer edge of their stars habitable zone, they are going to be a tad chilly. Even pro's refer to these worlds as 'Hoth Analogues.'

 

[Luís Santana]

portals

Hey ThinkerX you just triggered an issue I'm trying to "fix" (solve) for a while. [Thanks!]

I'm posting a new thread in World Building, to work that on...

... PORTALS.

 

[ClearDragon]

Well, I love thinking on planets...

Second planet first.

The only reason a planet with land masses and water has oceans and land is that the land is above or below the waterline, which has a lot to do with how hot core of the planet is in pushing water up. On a planet with the waterline below surface level, all (or...most) of the water would be underground. If that planet had craters from impacts, the craters would likely be filled with water. If the land had low areas, they could also form seas and oceans and such. If there was a powerful impact, the planet may not be a smooth ball, and some land is pushed above the water level and some isn't. If the water was ever on the surface and slowly sank, the land would be cut into river beds and high lands, as water would erode it and cut low areas into it.

If we were to slowly raise the water level on Mars, it would start to look like you describe.

Mars with oceans. The land area goes around the entire planet.



For the first...this is less likely, I think, but no one can say it could never happen. If it is just a single continent, that would seem more feasible. The reason being planet tilt which creates such zones in the first place. I don't think there is a way to have to planet spin such that all areas get equal heat (maybe its north-south was exactly a right angle to the planet). If the planet had any tilt, some areas would be hotter than others and cause good conditions in some areas and poor ones in others. But, if there was just one land mass and it happened to be in the zone where the conditions were best for jungle, then jungle it would most likely be.

I see, interesting. I'm considering many things about this now.

 

[ClearDragon]

Single climate planets in my mind never make any sense. Even here in the Netherlands, which is a country something like 250 by 400 km there is slight climatic differences between the coast and the interior. Increas that by a factor 10 to 100, add elevation differences, mountain ranges, water sources and the like, and there's no sense at all. Already just the fact that you've got a sphere means that places at the poles are cooler than at the equator, simply because the light from the star will be more concentrated at the equator than at the poles.

Now, the fact that they don't make sense doesn't mean they can't work. I think George Lucas showed that you can have single environment planets that everyone loves. The main reason I think it works for him is that he doesn't try to justify it. The story isn't about that. It's about the adventures of a boy, about space magic, not about the worlds.

So if you want them, go with it and have fun. Just don't try to make sense of it.

And consider ThinkerX 's suggestion of combining the two. Why does it have to be two planets?

Well, I sort of had the story first and then the plants...
One planet being a paradise with lush jungles with giant trees and also dragons. The other being dry and harsh yet with life still thriving.
My idea was to semi justify it with the jungle planet having a lot more greenhouse gasses. The Cornelius effect would have the gasses concentrated at the poles, meaning that the whole planet could have a smooth and mild climate change from the equator and the poles.
The desert planet would be the same, but have a lot less water.

 

[pmmg]

Well, some of the new exo-planets discovered probably do have a single climate zone, though they are the opposite of what the OP is after - ice worlds.

Not saying this isnt true, but with an ice world, it could also be that it does have climate zones, only they are all frozen. So the planet(iod) could fluctuate between freezing, and super freezing going through only seasons that still leave ice. The Earth had an ice age, and was completely frozen for a very long time, and it still had climate zones. The cycle of heating up and cooling off would still occur, just in a different range.

 

[Redfrogcrab]

My idea for this planet is a higher amount of greenhouse gasses and also a single supercontinent with a number of inland seas. Does that make any sense? Would that keep the planet tropical?

No, it wouldn't, a better solution would be an archipelago planet, where land masses are very small and very tall, as large, flat continents have a more difficult time in getting water vapor evenly distributed. It's also going to have to have lots of water that can be evaporated on a daily basis and then condense over a landmass, caught by the peaks of the tall islands, and rain down on the forests below.

Having no polar ice caps is pretty much impossible without getting into "suffocating and being boiled alive by the atmosphere" territory, so just accept small ice caps

My idea is a lot less water, maybe no real oceans, only seas on a planet spanning continent. There should be rivers and lakes I think too. Basically I want the climate zones of Arizona and Sonora spanning a planet. Does that make sense?

Yeah, this works, single biome planets are pretty much impossible outside of global ice caps or hell, but desert planets like this have some merit to them