Alternate Planets, Suns, Stars, and Solar Systems Thread

One program which may help out with generating a 'relatively realistic' solar systems, complete with all the data on orbits, mass, atmosphere compositions, etc... even moons to some extent is the Stargen program. It's based on the old ACCRETE program I've used it in the past (grabbed the source compiled and ran it through several iterations on my ubuntu box at home) and you can get very interesting systems. It doesn't give the best graphic representation in the output of systems (although I like the minimal SVG vector option) but you can get some pretty thorough stats regarding the planets themselves. (Link: http://www.eldacur.com/~brons/NerdCorner/StarGen/StarGen.html )
 
I made another alternate system based off of our planets. I mostly didn't draw anything on this, I just edited one of those Solar system graphics.

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I wonder how plausible such a solar system would be? Seems like you'd need a very specific set of circumstances not to have some of those objects ejected or collide while keeping at least some of those planets (Jupiter system? Venus?) habitable. Especially the Asteroid Belt, I'd think the larger objects would collide and accrete and form another planet. If they didn't then that's still a lot more mass than OTL (no Ceres?) and given Jupiter's mass I'd expect a higher rate of asteroid impacts. Not too high to prevent complex life (on the contrary, maybe even more diversity since there's more mass extinctions) but probably too high for intelligent life to emerge and stick around. Jupiter's gravity likely prevents Earth to Venus lithopanspermia but the reverse isn't true which assuming there's anything to that theory has some interesting implications. And then of course all the other bodies where extremophiles might arise or be transported to.
 
I wonder how plausible such a solar system would be? Seems like you'd need a very specific set of circumstances not to have some of those objects ejected or collide while keeping at least some of those planets (Jupiter system? Venus?) habitable. Especially the Asteroid Belt, I'd think the larger objects would collide and accrete and form another planet. If they didn't then that's still a lot more mass than OTL (no Ceres?) and given Jupiter's mass I'd expect a higher rate of asteroid impacts. Not too high to prevent complex life (on the contrary, maybe even more diversity since there's more mass extinctions) but probably too high for intelligent life to emerge and stick around. Jupiter's gravity likely prevents Earth to Venus lithopanspermia but the reverse isn't true which assuming there's anything to that theory has some interesting implications. And then of course all the other bodies where extremophiles might arise or be transported to.
My rule is that the multiverse is so vast in possibilities and quantities that anything is possible. Venus is a thick atmosphere type planet with water vapor and such, it's a mainly ocean type planet. It probably has whale and fish like life on it. The No Ceres thing is a mistake on my part, it should be somewhere.
 
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I wonder how plausible such a solar system would be? Seems like you'd need a very specific set of circumstances not to have some of those objects ejected or collide while keeping at least some of those planets (Jupiter system? Venus?) habitable.
It seems pretty plausible to me! There's evidence of a gas giant having impacted the sun, so this could really just mean that that giant and Jupiter interact in such a way that one gets ejected and the other eventually settles into a near-Sol orbit.
 


Made another one here, this time with more ideas.

Jupiter:

Jupiter is a scorched gas giant that orbits the sun. It has a lower mass than ours thanks to it's mass loss, causing a massive 'halo' to form around where it orbits and is constantly replenished by new gas that was lost by Jupiter. It orbits the sun in 3-4 days and is tidally locked. Referred to as the 'Dark Giant', it is more accurately the 'Dying Giant' because of its rapid mass loss.

The Vulcanoid Belt:

Where Mercury is in our solar system lies a massive belt of debris. It has the mass of our Mercury and is home to similar sized dwarf planets to ours and many others. Most of them are pure iron and very spherical in shape. There are spheres of iron up to hundreds of Kilometers in this zone, with little to no crusts. So, true floating iron balls in space.

Saturn:

A ringed gas giant where our Earth orbits, it is home to many moons. The Moon is the closest moon to Saturn, and it is ripped internally, causing massive volcanoes like that of Io's, however they are not as intense so you can have colors ranging from grey to yellow on its surface. Haumea is a weird moon that was struck by an object, breaking its tidal locking. Saturn has an asteroid belt around where Haumea is. Other moons of Saturn may have rings, and small moons of their own, implying that the collision was fairly recent in astronomical scales.

Callisto is a half and half world, like Iapetus. However instead of rock, it's half and half colors are made up of 2 different types of plant life. One side is the side that faces Saturn, the other side faces away. These plants are adapted for life on either side of Callisto, and along the terminator line is a 3rd type of plant life comprised of both types genetically combined. Callisto has an atmosphere like Earth's, and is protected by the Solard Win by Saturn's magnetosphere.

Uranus:

Uranus orbits where Mars is located. It orbits on its side, and with a closer location to the sun, it's storms go around at 1,600 miles per hour or more.

Neptune:

A purple planet where the asteroid belt is, it has 5 moons. It''s north and south poles have geometric storms, of a square and a triangle. Like Saturn's Hexagon.

Mercury and Io:

A small ice world that orbits where Jupiter orbits, it is in a binary pair with Io. Both worlds have cryovolcanism, and thin atmospheres. Tidally locked to one another, they orbit around each other every 16 days.

Venus and Europa:

A frozen ocean planet, Venus's surface is extremely smooth, it orbits closer to the sun than Saturn though further from Jupiter. It is made of blue ice that is partially see through, it is home to subterranean life that evolved on the planet before the oceans froze over. The life adapted and thrives around hotspots on the oceanic surface underneath. What is interesting about Venus is that it's oceans are separated, there are 9 different seas and oceans, all separated from each other underneath ice. These oceans have different characteristics, different ratios of chemical compounds in the water that make them different from one another, and thus the life is different. It's sky is blue like ours and slightly thicker at around 1.2 atmospheres. It's ice is around 2 miles thick.

Venus and Europa are tidally locked to one another and orbit around each other every 27 days. Europa is similar to Venus, minus the atmosphere. It has many underground ocean layers

Earth and Ganymede:

Earth has the most advanced life of this solar system, and orbits where Saturn orbits. It's atmosphere is similar to that of Titan though it is a bit thinner and denser, and it's oceans are made of Ethane and Methane. It has life that is similar to our own, intelligent life like that of humans. Imagine Humans with different body chemistry. However the thing with Earth is, is that the low light levels force life to conserve energy. So life moves very slowly. The 'humans' that evolved here have a different perception of time. They perceive 84 years as 1 year, and so they move extremely slowly, however they perceive that amount of time as we do. All life on this Earth is quite different from our own though similar. These humans are 'modern' though much of the technology they have will lack things we have due to the different temperatures, perhaps they would come up with completely different types of technology than ours.

Underneath Earth's surface is caverns and underground seas. These areas are home to life that preys on the life on the surface. The creatures that do so resemble flying stalks and arrows, and are able to move much quicker, though get tired extremely quickly as a result. Able to impale life on the surface, and harvest their rich nutrients. In the sky are large, amoeba like creatures that fly at extremely high altitudes and are normally invisible to human eyes, aswell as disc like creatures.


Ganymede has an atmosphere like that of Titan's. It's atmospheric structure is as the following.



Due to these haze layers, it's surface is forever shielded from that of the Earth's. It is also home to life. The most intelligent forms of life resemble frogs with 6 eyes instead of 2. They will forever be unaware of the world that theirs is rotating around, unless they somehow develop technology to go above the atmosphere. They are currently in an age similar to that of the bronze age.

Earth and Ganymede are tidally locked to one another and orbit around each other every 20 days.

Titan:

Titan is a world that shares Earth's orbit and is placed at the L4 Lagrange point. It is exactly as our Titan, though orbits the sun. Has no moons, and has similar life forms to that on Ganymede. 3 worlds spawned via panspermia, each evolving their own biospheres but not being aware of each other's existence. Not yet. Titan also has life that floats in the air, like floating algae.

Mars, Pluto, and Charon:

Mars is a blue iceworld. It has blue microbial life on its surface and underneath. Orbiting further than Saturn, it has a severe lack of sunlight so life was never able to evolve multi-cellular life. Mars has almost no atmosphere and is almost completely dead.

In Mars's sky orbits the dual moons of Pluto and Charon. Both moons orbit around each other in elliptical orbits to some degree, appearing at different positions from Mars's Surface. They orbit around Mars every 50 days and orbit around each other every 6 days.

There is a lack of a Kuiper belt, due to a large gas giant that orbits further out than Eris, though it is not pictured. Nemesis, an M9V star orbits at 4,000 AU from the sun. It has it's own planetary system, though that is for another day.
 
Er… the outgassing isn’t going to stay in a belt there. It’s going to stream out as a “cometary” tail larger than is comprehensible. It may well be partially accreted by Saturn (and its moons), but at any rate will affect the atmospheric composition of all bodies further out.
 
Er… the outgassing isn’t going to stay in a belt there. It’s going to stream out as a “cometary” tail larger than is comprehensible. It may well be partially accreted by Saturn (and its moons), but at any rate will affect the atmospheric composition of all bodies further out.
Hmm, it may form another distant ring around Saturn then. Fair enough.
 
Done some different ideas. Earth in place of other planets with their atmospheres / colors. I did some more realistic worldas for the solar system too. In no particular order.

Earth as Venus.


Mars Worlda.

Marsformed Earth.

Earth as Uranus

Earth as Neptune
 
I've been working on an ecology for a rogue planet, trying to flesh out the science that would allow a fully developed ecosystem to exist. The planet itself is Venus-sized, with a moon comparable in size to Mars; the idea is that a thick, insulating atmosphere combined with a thick crust and a massive moon to create tides would keep the planet warm and habitable despite having no star. The planet itself must have been flung from another solar system millions or even billions of years ago, as it still has the remains of seas on the surface; though most are concentrated in deep trenches or on plateaus as ice, there are shallow seas of water or some other liquid. Any thoughts on how else the concept could be improved?
 
as it still has the remains of seas on the surface
The best you’re going to get is a Europa analogue. Within a few thousand years any atmosphere is going to precipitate to the surface as frozen versions of the gases of which it was once comprised, and thereafter the oceans will be frozen miles thick–not just because you can’t have liquids exposed to vacuum, but because the temperature is too low. Plenty of room for liquid water below that, however, and temperatures suitable for “life as we know it” through tidal heating–>volcanic activity–>geothermal vents on the sea floor. As long as it brings a large enough moon along, that could continue “indefinitely” (for the purposes of any narrative).
 
I've been working on an ecology for a rogue planet, trying to flesh out the science that would allow a fully developed ecosystem to exist. The planet itself is Venus-sized, with a moon comparable in size to Mars; the idea is that a thick, insulating atmosphere combined with a thick crust and a massive moon to create tides would keep the planet warm and habitable despite having no star. The planet itself must have been flung from another solar system millions or even billions of years ago, as it still has the remains of seas on the surface; though most are concentrated in deep trenches or on plateaus as ice, there are shallow seas of water or some other liquid. Any thoughts on how else the concept could be improved?
Methane seas and quite a lot of radioactivity...
Or, do a Voga- have your biosphere include, crucially, something that produces hydrogen (or something else!). This hydrogen envelope is sustained, and as such you don't lose your atmosphere, and if it stays thick enough the radioactivity/tidal heat stays in and your seas are nice and melted.
 
I've been working on an ecology for a rogue planet, trying to flesh out the science that would allow a fully developed ecosystem to exist. The planet itself is Venus-sized, with a moon comparable in size to Mars; the idea is that a thick, insulating atmosphere combined with a thick crust and a massive moon to create tides would keep the planet warm and habitable despite having no star.
Earth mass is not enough to maintain the atmosphere at which the surface temperature of the rogue planet will reach 273K. Read the article discussing the issue of such planets, though it is in Russian. http://robert-ibatullin.narod.ru/planetar.html
 
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