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What I love about the idea of planetary systems around dwarf stars is that if the planets were close it would make interplanetary flight quite a bit faster and

• wruza 2y ago
  Also due to tidal lock “weather” they can simply kite their satellites (and rockets/missiles) to the orbit, for the most part. You open the hatch and let it fly. Don’t forget to close the hatch though, or your entire dream will fly too.
  • api 2y ago
    Whoa… I never thought of that. If complex life were possible on a tide locked planet that held onto its atmosphere you could ride the powerful currents this would create at least much of the way to orbit. You’d probably need a rocket to reach orbital velocity and escape but the atmosphere might be almost like your first rocket stage. Such a civilization would also have endless free energy via solar harnessed from the sun side and continuous prevailing powerful winds. The latter would probably get tapped first. Huge wind turbines would just always spin. This would be true from their dawning of industry, which would be interesting. No energy wars. I’m sure they’d find something else to fight about if they were aggressive and territorial like us.
    • cruffle_duffle 2y ago
      Wouldn’t the amount of habitable land mass on a tidal locked planet be rather small? Like the bulk of the planet is either hotter than hells freezer or colder than its hot tub. You’ve got only a fixed ring of land that would be usable. Unless life can survive & thrive in the remainder. Which I’m sure it can and does.
      • api 2y ago
        It would be quite different from Earth in lots of ways. The most habitable region would probably be the twilight zone but “life will find a way” as Jeff Goldblum famously said. Life would have been evolving for billions of years in that environment before intelligence arose. The temperature gradient might not be as nuts as you’d think. A thick atmosphere would develop powerful prevailing currents that would move heat from the hot side to the cold one, basically a heat engine. It would keep the hot side from being insane and the cold side from being cryogenic. My guess is that the far poles would be extreme but anywhere from 1/3 to 2/3 of the non-twilight sides would be potentially habitable by something. If there were large oceans you'd get prevailing currents there that would move heat too. There’d also be a water cycle. Imagine regions of the hot side where it rains a lot. You might have this hot steamy jungle in eternal daylight, meaning 2X the energy available for photosynthesis. There’d probably be critters that would migrate around. I can imagine stuff living on the night side by eating those, scavenging, etc. I wonder if an environment with massive prevailing winds would drive the evolution of wind energy harvesting? Imagine a big tree like thing with big leaves or vanes shaped to flap in the wind and specialized cells that use that mechanical energy to make food and nutrients. Muscles go from sugars to motion. Seems plausible that something could go the other way, especially with billions of years of evolution and a massive amount of energy available that way. If that kind of thing evolved you could have wind powered ecosystems on the night side and solar powered ones on the day side. Lots of possibilities.
      • chasil 2y ago
        With continental drift, the moving land might regularly undergo sterilization events.
        • jamiek88 2y ago
          Tectonics would be very unlikely.
• pfdietz 2y ago
  Although rockets could take you between closely spaced planets, the delta V to escape the system would be much greater than in our solar system, by an order of magnitude. The habitable planet would be much deeper in the star's gravity well than we are in our Sun's. Travel times between inner planets would be very short, I admit.
  • tomrod 2y ago
    You should be able to sling shot multiple times to improve that though?
    • pfdietz 2y ago
      Some, although I think that would need either lots of slingshots or really heavy planets. If there are many closely spaced planets it could work, I think, and the encounter cadence would be high. If there are lots of planets in closely spaced orbits I'd think orbital resonances could force planets into elliptical orbits, which would drive strong tidal heating, as on Io (but more so, due to the much stronger gravity of the primary.)
• forgetfreeman 2y ago
  Upvoted for "they probably look like crabs". I see what you did there and I am here for it.
• russdill 2y ago
  If it's super easy to get to orbit, it's also super easy for your atmosphere to get to orbit.
  • api 2y ago
    True. I was thinking of time between planets though. It’s hard to get to Earth orbit but it also takes six to twelve months to get to Mars without some kind of crazy torch rocket. In a smaller system it might take a few weeks. Big difference.
• hermitcrab 2y ago
  >They probably look like crabs though. It's crabs all the way down. https://en.wikipedia.org/wiki/Carcinisation https://en.wikipedia.org/wiki/Carcinisation