[Wip/Question] Devoloping "realistic" fantasy worlds - The SV Project

[Robulous]

Just as mapping is related to world-building, so astronomy is totally related to world-building. I'm the same as you, I've put a lot of thought into my world-building projects, I do try to make them as plausible as possible, or at least rationalise and explain any eccentricities.

Your idea about a ringed world grabbed my attention. I assume you really want to have a ringed world, so you'd have to think about how it's possible according to physics. Saturn, out in the cold depths where the sun is a bright star, has rings composed of chunks of ice. The rings are visible, and even glitter, because the chunks are constantly smashing into each other, forming and reforming. If this wasn't the case, interstellar dust would accumulate on the chunks and make them dull.

Big problem: chunks of ice won't survive in the goldilocks zone. The temperature in space on the day side of Earth, unprotected by the atmosphere, is hundreds of degrees.

Therefore, either your rings have to be made of something more durable (diamond dust?), or be constantly replenished. Jupiter also has a faint ring system mostly made up of dust kicked up from meteor impacts on the moons, cryovulcanism (geysers erupting ice crystals into space), and sulphur volcanoes on Io but unlike Saturn's glittery ice bling, it's not easily visible.

It's possible your planet could have a rocky ring system, but a large amount of solid matter in orbit would be a terrible hazard to life (ask a dinosaur), and it wouldn't stay up there long.

So I'd say lunar vulcanism or cryovulcanism is your answer, possibly one of each. The ring system would form in the orbit between the two.

[Scrit]

Yes, I'd have to say you're right about the water-ice within the "goldielocks zone," Robulous. Found a nice wiki page about [The Roche Limit] which at least details a starting point for ringed worlds and other matters to consider. Another site has this to say about the Roche Limit ...

The Roche limit is the minimal distance, with respect to the center of a planet, at which a satellite is able to orbit without being destroyed by tidal forces. If the planet and the satellite have the same density, the Roche limit is 2.5 times the radius of the planet. Within this limit, the satellite is destroyed by tidal forces.

Each of the ring systems in the Solar System are within the Roche zone of their planets.

Solid satellites can exist inside the Roche zone if they are sufficiently small, since the tension of the rocks prevent them from breaking up.

In a disk of remnants around a newly formed planet, the matter outside the Roche limit can form satellites, whereas nearer to the planet, the tidal forces prevent the formation of any satellite.

This mechanism still holds in the neighbourhood of a star : no planets can exist nearer than 2.5 times the radius of its star.

Yet another site mentions this about "Shepherding Moons."

What are shepherding moons?

Shepherding moons are satellites that orbit along side a ring. Due to gravitational effects from the shepherding moon, the edges of the rings are kept sharp and distinct. If the shepherding moon was not present, then the ring material would have a tendency to spread out. If two satellites are orbiting on both sides of the ring, then ring will be constrained on both sides into a narrow band.

So, that brings up the most likily position for a pair of moons, on this ringed world. On the outlaying edge of the ring, which have the pleasing effect of keeping the rings "sharp and crisp at the ends."
Certinally some things to consider here. I forget which site it was, but one had mentioned that large worlds are commonly ring worlds, so what I am looking at is the feasibility of a world that is at least twice the size of earth to have ringsof it's own.
[This Chart] compares Earth to both Uranus and Neptune. Both of which have much dimmer rings thatn Jupiter or Saturn.


This SV world is already taking shape.