CWBP 2 : Determining the genre and era

[Azélor]

I took a look at Ganymede and Titan, the two biggest satellites in our system to get an idea. They take about 7 to 16 days to orbit while the Moon takes 28 days. They are all tide locked. That mean that if your are on the tide locked side, you have nearly half of that time without light. This would make for big temperature variations and a huge impact of climate. It's possible to have a smaller orbit but then the tidal distortion is more intense.

So you need a gas giant or a solid planet heavier than the moon. In does not need to be very huge in fact. If you look at Pluto, the difference is rather small. And the planet could also be habitable but would be different from our earth for things like gravity and atmosphere. It is also possible that the planet could be tide locked with the satellite too, so both would end up tide locked. With two celestial bodies with a similar mass, it would greatly reduce the nasty distortion.

I'm not too sure about the amount of energy this would create but I don't think it would heat the surface much as it appears here in the article: ''However, the geophysical and atmospheric properties of extremely tidally-heated bodies are unknown, making habit ability assessments challenging. With Io’s surface tidal heating of about 2W/m2 in mind, which leads to rapid reshaping of the moon’s surface and global volcanism, we thus focus on moons in the IHZ for the time being. '' so the closer you are, the more energy is generated but it also cause massive distortion. And if you bring it a little closer, you wreck the satellite apart. But not too far either because the satellite could move out of the planet’s attraction.

Furthermore, the planet needs to be located in the habitable zone and correct me if I’m wrong but gas giant usually form far from the star. So I think a giant planet (or simply a bigger earth) would be a better idea.


This being said, I'm also interested at binary stars. I know how to make it stable gravitationally but I have not explored the impact it would have on climate yet.

[Ghostman]

I took a look at Ganymede and Titan, the two biggest satellites in our system to get an idea. They take about 7 to 16 days to orbit while the Moon takes 28 days. They are all tide locked. That mean that if your are on the tide locked side, you have nearly half of that time without light.

That can't be correct. The time without light would last only for as long as the moon remains in the shadow of it's mother planet. That certainly does NOT mean anywhere near half the period of it's orbit. The span of time depends on the moon's distance to the planet, as well as the diameter of the planet.

EDIT: Ok, now I see what you meant - the time the side facing the planet is facing away from the star. This actually applies to every location on the moon (save it's poles) equally, not just the tide locked side. That said, my second point (below) may still complicate things, depending on the angle...

What's more, you appear to be assuming that the plane of the moon's orbit around the planet is the same as the plane of the planet's orbit around the star. If these planes are tilted relative each other at a significant angle, the moon won't actually enter the planet's shadow at all for much of the year.