I’m looking to create a situation where there are 3 habitable planets (or moons) in the same system, each with different inhospitable but habitable (by genetically modified humans or humans using supportive technology) environments.
I’ve been roughly basing it on the TRAPPIST-1 system, as it has 4 planets in the habitable zone, but I don’t know if there is a simpler way to have 3 habitable but different environments in relatively close proximity (maybe using moons)?
I thought there could maybe be artificial magnetosphere generators to protect the planets from solar flares (maybe something like this? https://www.sciencedirect.com/science/article/pii/S0094576521005099 ), although maybe the worst of the flares would not affect the planets ( https://phys.org/news/2021-08-superflares-exoplanets-previously-thought.html )
Planet A (closest to the sun, based loosely on TRAPPIST 1d)
Terrestrial planet with orbit of 4 days
Closest to Star, so hot and barren on star side, water on night side (flowing sea under ice cap).
0.6 earth mass (in reality Trappist 1d is 0.3 earth mass, so not sure how this change will things)
Life is possible around the terminator (I thought of maybe cloud cover to increase the habitable zone, but apparently that may make it too dark for photosynthesis https://www.centauri-dreams.org/2013/07/05/red-dwarfs-clouds-in-the-habitable-zone/ ).
Requires terraforming to create atmosphere.
Planet B (second closest to the sun, based very loosely on TRAPPIST 1e)
Terrestrial planet with orbit of 6 days
0.8 earth mass
Kind of like a dim earth
I would prefer that the last two planets are not tidally locked, and apparently the presence of an atmosphere avoid tidal locking ( https://physicsworld.com/a/exoplanets-could-avoid-tidal-locking-if-they-have-atmospheres/#:~:text=For%20example%2C%20a%20planet%20orbiting,and%20liquid%20water%20can%20exist. ), so ideally this planet is not tidally locked as it already has an atmosphere (though I don’t know if a thin earth like atmosphere would be sufficient in this case?) Also, at the end of this article it mentions that “the close-in worlds of small stars face other challenges. For example, a planet near its star speeds through space quickly, as Mercury does, so asteroids and comets can smash into the world so fast they may eject its atmosphere”, so perhaps some additional shielding would be required?
Planet C (third closest to the sun, based very loosely on TRAPPIST 1f/g)
Orbit of 8 days
Largest at 1.2 earth mass
Has atmosphere so not tidally locked.
Maybe like an ice world, but not too extreme, so still habitable (though maybe not possible to grow plants on the surface)
I am a complete beginner to both worldbuilding and astronomy, so any input would be greatly appreciated!