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Nov 22, 2020
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While in reality moons are often tidal locked relative to their planet, in the game the modifier "Tidal Locked" rather concerns the relationship with the sun.
This world is tidally locked around its star, meaning that one side always has daylight while the other is locked in eternal darkness.
If life exists here, it is likely limited to the twilight regions where the two sides meet.
A moon that is tidal locked to its planet is not tidal locked to its sun, and will therefore not suffer from only a "twilight zone" being habitable.
Contrary to this reality, the probability of a moon getting the "Tidal Locked" modifier is currently increased by a factor of 3.

Suggested changes:
  • Moons should not get the "Tidal Locked" modifier.
  • "Tidal Locked" should be much more common for planets orbiting red dwarves and brown dwarves.
    (Weak magnetic fields should perhaps also be more common there.)
  • All planets in the Trappist system should have the "Tidal Locked" modifier.
 
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While moons often are tidal locked relative to their planet, the modifier rather concerns the relationship with the sun.

Currently, the probability of a world getting the "tidal locked" modifier is increased by a factor of 3.
Considering what the modifier is supposed to represent, the factor should rather be 0.
Have you a data for this, as our moon isn't?
 
Have you a data for this, as our moon isn't?
Do you mean in-game or real life? If you mean in real life, our moon is definitely tidally locked to Earth. That's why we always see the same face of the moon throughout its orbit around the planet. The same applies to all major moons throughout the solar system.
 
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Yeah, being a moon should prohibit the "tide locked" modifier.

Tide-locked planets should probably not have a moon, either.

It'd be cool if there were some unique planet classes for moons.
 
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Tide-locked planets should probably not have a moon, either.

Not really?

Nothing in our understanding of physics prohibits tidally locked planets having moons. There's a few theories floating around about the idea that the moon would have a slow drift inwards rather than outwards but nothing says that it's impossible.

Hell, even both a tidally locked planet and moon isn't theoretically impossible even if it is practically so

You'd need the moon to be very distant from the planet, the planet to have a very strong gravitational pull and both the planet and the moon having both the exact same rotation speed and orbital period which would have to match, IIRC.

Assuming that I'm not misremembering which is entirely possible, it's the kind of thing that can happen on paper but you aren't going to see it in reality.
 
"Tidal Locked" should perhaps also be much more common in red dwarf systems?
And make it more likely that the world gets the "Weak Magnetic Field" modifier?
(I guess this would apply to brown dwarves as well.)
 
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How about having different tidal-locked modifiers for planets and moons. The current ones for planets and a new one (Tidal-locked to planet) for moons, which shouldn't really have all that much of an impact, but perhaps some minor in-game effect would be ok.
 
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For a tidal-locked inhabitable moon, I'd see less generator districts (no tides, and a little shadow from the planet, hence less energy in atmosphere), and a small income in Social research (because of the dichotomous flora).
 
I can't really think of any bonus or malus that moons would get from being tidal locked to their planet, as far as habitable worlds and colonies are concerned.
Adding a modifier that does not modify anything would be strange.
They could get some "Long-Period Day" Modifier, as could planets with slower-than an Earth-like rotations. Roche limits prevent a large habitable moon from orbiting too close to its parent planet, and distance to the parent planet will be correlated to the rotation speed of the moon. Closer in moons will rotate faster than ones further out. Io's day is about 1.75x longer than Earth's, and that's already close enough in to be straining under under the gravitational influences of Jupiter and its neighboring moons. Europa's day is about 3.5x longer than Earth's, Ganymede's is 7x longer, Callisto's and Titan's are both around 16x longer. Anything with a day more than twice as long as Earth's will have a radically different weather pattern - most likely more evenly distributed temperatures from equator to pole, since are hot air from the equator will be able to reach all the way up to the poles rather than being deflected by the Coriolis effect. But they'll also have to contend with more extreme differences between day and night temperatures.
 
I'd see less generator districts (no tides...)
You'd still have tides on a tidally locked moon, and potentially pretty strong ones if there are other large moons in the vicinity, similar to the Galilean Moons.

On a basic level, you still have interactions between the moon, parent planet, and the sun(s), which will influence the tides on the moon as their gravitational influence aligns or acts perpendicular to each other. Throw in some other large neighboring moons pulling the habitable moon every-which-way and things get pretty crazy. That inter-moon tidal craziness, in addition to being so close to Jupiter, is why Io is as volcanic as it is.
 
A non-tidally locked moon wouldn't really be a thing, barring a few exceptional cases. All the major moons of the Solar system are tidally locked and that's probably going to to be true elsewhere in the galaxy.
 
A non-tidally locked moon wouldn't really be a thing, barring a few exceptional cases. All the major moons of the Solar system are tidally locked and that's probably going to to be true elsewhere in the galaxy.
Charon and Pluto are mutually tidally locked, but a consequence of that is that all it's other moons are not tidally locked.

Hyperion, one of the moons of Saturn is not tidally locked. To be honest, most of Saturn's moons aren't but they're usually listed as minor moons.

Moons that aren't tidally locked actually seem to be more common than those that are, it's just that the major ones tend towards being tidally locked.

Basically, the closer they are to a planet, the higher the odds of being tidally locked.

Since gas giant's tend to pick up a lot of "distant" moons it throws the trend towards moons not being tidally locked.

If you exclude gas giants then the trend is towards tidally locked moons with the rare exceptions like what's happening with Pluto.
 
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Moons that aren't tidally locked actually seem to be more common than those that are, it's just that the major ones tend towards being tidally locked.
Yeah, I should have been more clear. I was specifically thinking about "moons big enough to be habitable" but didn't make that clear. The minor moons with chaotic rotations like the outer moons of Pluto weren't really on my radar in that post. Hypothetically a big moon could get captured in the outer region of the a gas giant's Hill sphere and maintain a non-locked rotation, but that'd be one of those exceptional situations I was referring too. Closer in, as you mentioned, they're more likely to get tidally locked.

Also, thanks for mentioning Hyperion by name. I knew at least one of the mid-sized moons wasn't tidally locked but I couldn't remember which one it was. I kept getting interference from Proteus - the largest moon that isn't in hydrostatic equilibrium. Those outer planets just have too many moons to keep track off. We need to get a Planet Cracker and some mining stations out there soon to take care of that problem for us.
 
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Is there a separate term for a celestial body being tidally locked to the star (not a planet)?

Because the above conversation seems to be technically correct, but I'm not sure how it's supposed to be related to the game's "Tidal Locked" modifier, which is only about being tide-locked to a star.
 
Is there a separate term for a celestial body being tidally locked to the star (not a planet)?

Because the above conversation seems to be technically correct, but I'm not sure how it's supposed to be related to the game's "Tidal Locked" modifier, which is only about being tide-locked to a star.

Sadly, no.

As far as I can tell there exists no proper distinction between a tidal lock tied to the sun and one tied to a planet. You could possibly use "solar tidal lock" for the sun but I don't think it's actually a correct term.

And there's no terminology whatsoever to describe the situation involving Pluto and Charon where the two are tidally locked to each other so that both only ever show the other the same face.

I think that's actually utterly unique in terms of what we've seen in space.

I think it can only happen because Pluto's "day" and Charon's orbital period are the same.
 
Is there a separate term for a celestial body being tidally locked to the star (not a planet)?

Because the above conversation seems to be technically correct, but I'm not sure how it's supposed to be related to the game's "Tidal Locked" modifier, which is only about being tide-locked to a star.
We could hypothetically borrow, or at least emulate, some terminology from Orion's Arm. They use the term "Vesperian" to refer to tidally-locked terrestrial planets (as opposed to tidally locked moons), in reference to their habitable "twilight" zones. There are a few subtypes, most notably the "Polyphemian" worlds. In real-world astronomy, these are usually called "eyeball planets" (hence being named after a famous cyclops), and are tidally-locked worlds near the outer edge of their habitable zone, where the twilight zones are frozen but the day side is habitable and usually depicted as watery - so you get a blue oceanic iris surrounded by white ice.
 
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"Tidal Locked" should perhaps also be much more common in red dwarf systems?
And make it more likely that the world gets the "Weak Magnetic Field" modifier?
(I guess this would apply to brown dwarves as well.)
Speaking of the above mentioned suggestion that "Tidal Locked" should be very common for planets in red dwarf systems: it seems like all planets of Trappist-1 should have the property.

TRAPPIST-1 on Wikipedia