Alternate Planets, Suns, Stars, and Solar Systems Thread

Heres a stupid alt solar system map I’ve been working on for a couple weeks. Not intended to be realistic.
 

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Heres a stupid alt solar system map I’ve been working on for a couple weeks. Not intended to be realistic.
That's cool! Some things I'm curious about:
What are the orbits of all of these - are the OTL planets unmoved, does Pluto's orbit still cross that of Neptune? Where did Vall go, and why are Tylo and Laythe switched? Which planets and moons have atmospheres and how thick are they (Mercury has liquid water)? Is Venus just Eve under a different name, or is it something else entirely? Has Mars been visited/colonized by humans? What size is Paradise and how far from Earth does it orbit? Do lifeforms on Paradise, Earth, and Mars share a common origin? Is life native to Paradise and Mars or was it only introduced by human activity? Are Phobos and Deimos unchanged? What size, shape, orbit, etc. are Cassini, Neith, and Mariner? How big are Vulcan and Arkis, how close to the sun do they orbit, do they have atmospheres, and is that a lava ocean on the daylight side of Vulcan? Is Arkis tidally locked? What is Arkis made of, to be that color? Is Neith ice, or something else? I assume the radii aren't to scale - how big are Prometheus, Jool, Pluto, and Janus compared to the other planets? Any particular reason to move Ganymede inward? Is that liquid water on the surfaces of Io, Ganymede, and Titan? Is there life on Laythe, Io, Ganymede, or Titan? It looks like Rhea has an atmosphere and oceans - what are they made of? How is Persephone hot enough that, even so far from the sun, it only has ice around the pole? Are the other moons of Pluto and Janus just the OTL objects in different spots? How big and how far away from the sun is Terminus? Is there anything I haven't asked about that you'd like to share?
 
That's cool! Some things I'm curious about:
What are the orbits of all of these - are the OTL planets unmoved, does Pluto's orbit still cross that of Neptune? Where did Vall go, and why are Tylo and Laythe switched? Which planets and moons have atmospheres and how thick are they (Mercury has liquid water)? Is Venus just Eve under a different name, or is it something else entirely? Has Mars been visited/colonized by humans? What size is Paradise and how far from Earth does it orbit? Do lifeforms on Paradise, Earth, and Mars share a common origin? Is life native to Paradise and Mars or was it only introduced by human activity? Are Phobos and Deimos unchanged? What size, shape, orbit, etc. are Cassini, Neith, and Mariner? How big are Vulcan and Arkis, how close to the sun do they orbit, do they have atmospheres, and is that a lava ocean on the daylight side of Vulcan? Is Arkis tidally locked? What is Arkis made of, to be that color? Is Neith ice, or something else? I assume the radii aren't to scale - how big are Prometheus, Jool, Pluto, and Janus compared to the other planets? Any particular reason to move Ganymede inward? Is that liquid water on the surfaces of Io, Ganymede, and Titan? Is there life on Laythe, Io, Ganymede, or Titan? It looks like Rhea has an atmosphere and oceans - what are they made of? How is Persephone hot enough that, even so far from the sun, it only has ice around the pole? Are the other moons of Pluto and Janus just the OTL objects in different spots? How big and how far away from the sun is Terminus? Is there anything I haven't asked about that you'd like to share?
1. Pluto's orbit straightens out to be way more stable than OTL.
2. Gone reduced to ashes...
3. I didn’t realize until just now that some of these planets were taken from other lore, I used the skins for these planets from some kit.
4. Same as 3.
5. Mercury has an extremely thin atmosphere, however a Goldilocks zone forms between the tidally locked sides making shallow water oceans possible.
6. Same as 3.
7. Life on Mars emerged separately from Earth/Paradise.
8. About the size of the moon, if not a little bigger.
9. Close enough to be heated by tidal forces.
10. Paradise/Earth life shares a common origin.
11. Yes they are unchanged.
12. Cassini and Neith follow a relatively stable orbit around Venus. Mariner has a highly eccentric and wobbly orbit (Probably a captured object that moved into the inner solar system)
13. Both are about the size of OTL Mercury.
14. Vulcan orbits much closer to the sun, and Arkis orbits around where Mercury is OTL.
15. Vulcan does have a lava ocean and is tidally locked.
16. Realistically it would be, but Arkis is not tidally locked.
17. I want to say it’s a desert planet, but that seems a little generic.
18. Neith is Ice, at first I imagined it as a thick atmosphere like OTL Venus but it definitely couldn’t hold it for long.
19. Prometheus is the smallest gas dwarf, it and Jool are closest to Neptune and Uranus in size. Pluto is smaller than Saturn and larger than the gas dwarfs. Janus is similar to Neptune.
20. No reason at all.
21. All of them have water.
22. Some of them are thought to have microbial life, nothing too complex yet.
23. Rhea as a swamp planet goes hard.
24. I’m gonna chalk to Persephone being a captured body from elsewhere in the Solar System.
25. Yes, I shamelessly moved around some Kuiper Belt objects to buff up the moon counts.
26. Smaller than Mercury, I cant make an OTL comparison in case I mess up and overlap with any other object I have on the Map.
 
If Earth's atmosphere were 370 miles thick (as thick as Titan's) rather than our 300, how much extra heat and moisture would it hold?
This is not really a very sensible question, since the "thickness" of the atmosphere is dependent on its temperature, composition, the gravitational pull of the parent planet, mass...all of which have a much larger effect on "heat and moisture" than "thickness" by itself. If you gave the Earth a much more massive atmosphere but it had a negligible inclusion of greenhouse gases, for example, it would retain less heat and less moisture than Earth's actual atmosphere, even if it was "thicker".
 
This is not really a very sensible question, since the "thickness" of the atmosphere is dependent on its temperature, composition, the gravitational pull of the parent planet, mass...all of which have a much larger effect on "heat and moisture" than "thickness" by itself. If you gave the Earth a much more massive atmosphere but it had a negligible inclusion of greenhouse gases, for example, it would retain less heat and less moisture than Earth's actual atmosphere, even if it was "thicker".
I think he meant “assuming identical composition, but an increase in volume such that, after compression due to extra weight it extends to ~370 miles.” I ran through the same sort of questions when I read it the first time, myself.
 
I think he meant “assuming identical composition, but an increase in volume such that, after compression due to extra weight it extends to ~370 miles.” I ran through the same sort of questions when I read it the first time, myself.
If Earth's atmosphere were 370 miles thick (as thick as Titan's) rather than our 300, how much extra heat and moisture would it hold?
Would that mean keeping the same scale height? And what criterion are we using as the "edge" of the atmosphere (because you give 300 mi, but the Kármán line is only 62 mi)?
 
So for this system - it's a rough draft. Am looking forward to see what people here think of my ideas for it. I'm intended to be realistic with this one. Not everything in this chart is finished, and is subject to change. Am looking for comments, questions, etc so I can make this better.

The Star here is basically more or less Sun-like. It is named Thale. G3V star. 99% the mass of the Sun, 98% Luminosity. Similar age to that of the Sun, too.

Fenheiser - The first planet. It's roughly twice Earth's mass, and is subject to the Star's intense rays. It has the shortest orbital period of any planet in this system, orbiting around the star every 16 hours. It's surface is molten and broken apart by the star's intense solar rays. It is tidally locked. The planet is host to large scale volcanism. Because of the planet's close proximity to the star - the solar wind interacts with the planet's volcanism and creates hypersonic volcanic winds. Around the planet is a halo of gaseous material. The planet very likely has a comet-like tail due to the planet constantly erupting material which is then carried away by the solar wind.

Sarnis - The second planet. At about the mass of Mercury, this planet is tidally locked. It orbits further away than Fenheiser, resulting in a rather two tone appearance. On the sun facing side, it has a magma ocean. On the side that faces away, it resembles that of Mercury. It has frozen craters, and it's dark side is one of the coldest places in the solar system. The planet has a magnetosphere - similar to that of our Mercury, which creates intermittent planetary auroras, giving a nice backdrop to the view of the other planets.

Fenheiser and Sarnis have no Moons.

Laurel - The third planet. It is the mass of the Moon - and basically fills the role of Dres in this system. It's a cratered and pockmarked world. The planet is geologically dead as a whole. It has a small asteroidal moon that is 10km in size that orbits fairly close to itself like Phobos is to Mars, named Crackstone. It also has no magnetic field.

The next are a binary planet. Magloria is the Neptune-like planet with a mass of 13 Neptune Masses. It has a fairly Neptune like look to it. It's binary companion is named Collapse. Collapse is an Earth mass world with similar atmospheric and temperature conditions to that of the Earth. Collapse is tidally locked to Magloria. It is possible Magloria and Collapse may have a system of minor moons that orbits around them.

Enidis is the next planet. It's slightly smaller than Earth's Moon and has a ring system half as wide as the Moon itself. For such a small planet, it's ring system is quite reflective. Enidis has various minor moons, and it's ring system was formed by one of them getting ripped apart in it's roche limit fairly recently in geological history. Enidis, much like Laurel - is geologically dead.

Margape - the 7th planet. It is a large Super-terran world, without about 4 times the mass of the Earth. It has fairly low density, making the planet a bit larger than a planet it's mass normally should be. It is very Mars-like, with a thin atmosphere. Unlike Mars, the atmosphere is thick enough to have standing liquid water on it's surface, although rare. Margape has a large ring system, and has four major moons. The first moon is about the mass of Pluto, while the second Moon is similar in Mass to that of our Moon. The following two Moons are Ceres Mass.

Indrimea - The 8th planet. It is roughly Saturn mass, with a fairly massive and reflective ring system. It has an entourage of Moons, the first major moon being similar to that of Io. The last two major Moons are warmer / wetter versions of Titan, with ethane lakes and rivers. The 3 other small major moons are similar to that of Tethys. Enceladus, and Dione respectively.

There exists a massive asteroid belt after Indrimea (the Equivalent of the distance from Jupiter to that of Uranus...roughly). It has 4 dwarf planets, all of which are similar in size to that of Eris. One of them rotates rapidly, in a manner like that of Haumea.

After the asteroid belt, there is a Jovian mass world named Vibrant. Similar to our Jupiter, it has a thin but barely visible ring system. It's largest moon is 2.5x the Mass of the Earth - a living Titan-like world. With oceans, rivers, and complex ecology that exists on that large Moon. The large Moon is named Arianis.

The next pair of planets are named Posos and Dahl respectively. Posos is about 21 times the mass of the Earth, while Dahl is about half as Massive as the Earth and has a look similar to that of Triton.

The planet after Poses and Dahl is Ganymede in size - with vast collection of minor moons to keep it company. It has a thin ring system similar to that of Neptune's rings. It is named Izz. An icey world, with a vast sub-surface ocean.

The last planet is named Mistros. A large world, about 40 times the mass of Earth. It has 6 minor moons, similar to that of Saturn's Moons, all of which are Enceladus in Mass. Interestingly enough, in it's sphere of influence is the captured planet named Opalina, a hot house - Venus type planet that undergoes tectonic activity, much like the Venus of our world. In the present day in this system, the planet exists as a Magma ocean thanks to it's geologic activity.


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I put our solar system here so one can see roughly where the positions and layout of this system is as compared to our own. The layout of this system is subject to change. Any thoughts, questions, considerations anyone has for this system?

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So for this system - it's a rough draft. Am looking forward to see what people here think of my ideas for it. I'm intended to be realistic with this one. Not everything in this chart is finished, and is subject to change. Am looking for comments, questions, etc so I can make this better.

The Star here is basically more or less Sun-like. It is named Thale. G3V star. 99% the mass of the Sun, 98% Luminosity. Similar age to that of the Sun, too.

Fenheiser - The first planet. It's roughly twice Earth's mass, and is subject to the Star's intense rays. It has the shortest orbital period of any planet in this system, orbiting around the star every 16 hours. It's surface is molten and broken apart by the star's intense solar rays. It is tidally locked. The planet is host to large scale volcanism. Because of the planet's close proximity to the star - the solar wind interacts with the planet's volcanism and creates hypersonic volcanic winds. Around the planet is a halo of gaseous material. The planet very likely has a comet-like tail due to the planet constantly erupting material which is then carried away by the solar wind.

Sarnis - The second planet. At about the mass of Mercury, this planet is tidally locked. It orbits further away than Fenheiser, resulting in a rather two tone appearance. On the sun facing side, it has a magma ocean. On the side that faces away, it resembles that of Mercury. It has frozen craters, and it's dark side is one of the coldest places in the solar system. The planet has a magnetosphere - similar to that of our Mercury, which creates intermittent planetary auroras, giving a nice backdrop to the view of the other planets.

Fenheiser and Sarnis have no Moons.

Laurel - The third planet. It is the mass of the Moon - and basically fills the role of Dres in this system. It's a cratered and pockmarked world. The planet is geologically dead as a whole. It has a small asteroidal moon that is 10km in size that orbits fairly close to itself like Phobos is to Mars, named Crackstone. It also has no magnetic field.

The next are a binary planet. Magloria is the Neptune-like planet with a mass of 13 Neptune Masses. It has a fairly Neptune like look to it. It's binary companion is named Collapse. Collapse is an Earth mass world with similar atmospheric and temperature conditions to that of the Earth. Collapse is tidally locked to Magloria. It is possible Magloria and Collapse may have a system of minor moons that orbits around them.

Enidis is the next planet. It's slightly smaller than Earth's Moon and has a ring system half as wide as the Moon itself. For such a small planet, it's ring system is quite reflective. Enidis has various minor moons, and it's ring system was formed by one of them getting ripped apart in it's roche limit fairly recently in geological history. Enidis, much like Laurel - is geologically dead.

Margape - the 7th planet. It is a large Super-terran world, without about 4 times the mass of the Earth. It has fairly low density, making the planet a bit larger than a planet it's mass normally should be. It is very Mars-like, with a thin atmosphere. Unlike Mars, the atmosphere is thick enough to have standing liquid water on it's surface, although rare. Margape has a large ring system, and has four major moons. The first moon is about the mass of Pluto, while the second Moon is similar in Mass to that of our Moon. The following two Moons are Ceres Mass.

Indrimea - The 8th planet. It is roughly Saturn mass, with a fairly massive and reflective ring system. It has an entourage of Moons, the first major moon being similar to that of Io. The last two major Moons are warmer / wetter versions of Titan, with ethane lakes and rivers. The 3 other small major moons are similar to that of Tethys. Enceladus, and Dione respectively.

There exists a massive asteroid belt after Indrimea (the Equivalent of the distance from Jupiter to that of Uranus...roughly). It has 4 dwarf planets, all of which are similar in size to that of Eris. One of them rotates rapidly, in a manner like that of Haumea.

After the asteroid belt, there is a Jovian mass world named Vibrant. Similar to our Jupiter, it has a thin but barely visible ring system. It's largest moon is 2.5x the Mass of the Earth - a living Titan-like world. With oceans, rivers, and complex ecology that exists on that large Moon. The large Moon is named Arianis.

The next pair of planets are named Posos and Dahl respectively. Posos is about 21 times the mass of the Earth, while Dahl is about half as Massive as the Earth and has a look similar to that of Triton.

The planet after Poses and Dahl is Ganymede in size - with vast collection of minor moons to keep it company. It has a thin ring system similar to that of Neptune's rings. It is named Izz. An icey world, with a vast sub-surface ocean.

The last planet is named Mistros. A large world, about 40 times the mass of Earth. It has 6 minor moons, similar to that of Saturn's Moons, all of which are Enceladus in Mass. Interestingly enough, in it's sphere of influence is the captured planet named Opalina, a hot house - Venus type planet that undergoes tectonic activity, much like the Venus of our world. In the present day in this system, the planet exists as a Magma ocean thanks to it's geologic activity.


View attachment 812873

I put our solar system here so one can see roughly where the positions and layout of this system is as compared to our own. The layout of this system is subject to change. Any thoughts, questions, considerations anyone has for this system?

View attachment 812874

Like it, a few thoughts Sarhis would likely have glaciers on the dark side, with a very thin atmosphere and so close to the sun small amount of hydrogen from the sun will hit the surface of Sarnis, where it free up oxygen from the rocky surface. This will be part of the atmosphere on the warm side, but as it enter the cold dark side, it will fall as snow and slowly build up. Over the eons this will create a lot of water ice.
 
Like it, a few thoughts Sarhis would likely have glaciers on the dark side, with a very thin atmosphere and so close to the sun small amount of hydrogen from the sun will hit the surface of Sarnis, where it free up oxygen from the rocky surface. This will be part of the atmosphere on the warm side, but as it enter the cold dark side, it will fall as snow and slowly build up. Over the eons this will create a lot of water ice.
That is more or less what I was thinking. What do you think about the other planets? Do you think the positioning of them and the planets themselves is realistic?
 
That is more or less what I was thinking. What do you think about the other planets? Do you think the positioning of them and the planets themselves is realistic?

I think Mistros and Magloria are the wrong places. Mistros sound like an ice giant and an ice giant too close to the sun turns into either earth, Venus or a super earth as the lighter gases are boiled away. While Venus couldn’t be created in the outer solar system, as the lighter gasses wouldn’t be boiled away.

Magnolia could theoretical have migrated in system relative recently (the last billion years) and the gases haven’t been boiled away yet. Mistros if it had migrated outward on the other hand would end up radical different so far from the sun, but very interesting in its own right. It would likely be a very cold world with a thick nitrogen atmosphere and covered in a desert frozen CO2, unless itwas bombarded with water meteor in its migration, the hydrogen in the water and the CO could have created a methane sea. So in that case you would have methane seas on top an ice bedrock, and below that you would have water sea on top of a rocky bedrock.
 
I think Mistros and Magloria are the wrong places. Mistros sound like an ice giant and an ice giant too close to the sun turns into either earth, Venus or a super earth as the lighter gases are boiled away. While Venus couldn’t be created in the outer solar system, as the lighter gasses wouldn’t be boiled away.

Magnolia could theoretical have migrated in system relative recently (the last billion years) and the gases haven’t been boiled away yet. Mistros if it had migrated outward on the other hand would end up radical different so far from the sun, but very interesting in its own right. It would likely be a very cold world with a thick nitrogen atmosphere and covered in a desert frozen CO2, unless itwas bombarded with water meteor in its migration, the hydrogen in the water and the CO could have created a methane sea. So in that case you would have methane seas on top an ice bedrock, and below that you would have water sea on top of a rocky bedrock.
Mistros is an ice giant similar to that of Neptune. It is a mid-way between Neptune and Saturn mass, at 40 Earth masses, roughly, so I don't see how it could have ended up with a frozen desert - as it's so massive. It exists far beyond the Kuiper belt, in equivalent distances.

Magloria is in the habitable zone, I don't see how such distances would boil away the gasses - as there Jupiter and Neptune mass planets around other stars in their habitable zones in a similar manner like Magloria.
 
In interstellar space a sphere slightly smaller than Earth moves at 5% of light speed. Any calculating its weight from the outside would quickly know that it’s hollow. The surface is made of uniform silicate except for the large radiators dumping heat into the interstellar medium and giant rocket motors placed to make it able to navigate.

If you moved inside you would find fortytwo Mckendree Cylinders placed in an Icosahedron. Anyone who knew of Earth could calculate that these habitats made up more space than the planet Earth.

What you’re seeing is the generationship Vernegaard. Most would think this giant ship would have been the work of generations, built with the full industry of an entire star system. In truth it’s simply one among hundreds of similar generationship leaving the solar system. The building of Vernegaard took only a decade, of course establishing its internal ecosystems took half a century. While the ship can handle billions of people the original crew was only a few millions and most of the habitat were and still are nature reserves, meant to bring all the diversity of Earth with it. Some habitats are vast jungles, others are the recreation of the ancient mammoth steppes. The two centuries of travel have increased the crew size to 150 million people and it’s expected they will reach a billion people at arrival. The crew mostly live in two temperate habitats, these are mostly farmland, managed woodland, and small seas.

Their target destination was selected decades before Vernegaard was built and a faster interstellar exploration vessel was sent there ahead of time. It has already arrived and makes sure that there’s no alien life or other danger and began the seeding of the moon in question with Terran life and begun developing the local infrastructure.

Some of Vernegaard’s sister ships have already arrived at their destination and begun the terraforming of their targets. Other ships have begun their trip to stars even farther away.
 
The biggest stretch here technologically is probably the idea of a hollow silicate sphere of that size and mass not collapsing in on itself, or being able to take the stress of acceleration.
What is the point of the sphere? Shielding of some kind?
 
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