D&D Setting Advice: Planet with Rings

[ssampier]

My players and I were discussing what kind of setting we would like to play in. One player mentioned he likes the idea of a planet with rings, where the rings have some sort of holy or godly significance. I like this idea and would like to expand it out, possibly as a setting "hook" a la "Dungeoncraft".

First, I am not an astronomer, so how are planetary rings formed? What are the effects of a planet with rings?

 

[Klaus]

Welcome to Eberron. It is circled by the Ring of Syberys (said to be the remnants of the great progenitor dragon Syberys, also known as the Dragon Above). Periodically, shards fall from Syberys into the continents of X'endrik and Argonessen. The Ring is said to be the source of magical energy, and clerics that revere no gods can, in fact, draw their divine power directly from the ring.

 

[sukael]

My players and I were discussing what kind of setting we would like to play in. One player mentioned he likes the idea of a planet with rings, where the rings have some sort of holy or godly significance. I like this idea and would like to expand it out, possibly as a setting "hook" a la "Dungeoncraft".

First, I am not an astronomer, so how are planetary rings formed? What are the effects of a planet with rings?

Real-life planetary rings are basically formed from all the left-over bits that didn't actually become the planet, plus anything pulled into a mostly-stable orbit by its gravity. Rather than solid surfaces, the rings are basically mini-asteroid-belts, composed of chunks from golf-ball-size to (IIRC) several miles across.

NOTE: I'm not an astronomer either, and basically just going from memory here.

 

[ssampier]

Sounds great. Assuming an earth atmosphere, are the rings visible during the day? Or at night?

I'm imagining placing some cool monsters on one of those asteroids in the ring.

 

[sukael]

Sounds great. Assuming an earth atmosphere, are the rings visible during the day? Or at night?

I'm imagining placing some cool monsters on one of those asteroids in the ring.

Oooh, ref page. http://en.wikipedia.org/wiki/Planetary_ring

The origin of planetary rings is not precisely known, but they are thought to be unstable and dissipate over the course of tens or hundreds of millions of years. As a result, current ring systems must be of modern origin, possibly formed of debris from a moon that suffered a large impact or was disrupted by the parent planet's gravity when it passed within the Roche limit.

Definite plot idea there... maybe the remains of whatever lived in the original planet/moon still lives among the rings?

The composition of ring particles varies; they can be either silicate or icy dust. Larger rocks and boulders can also be present.

So they'd probably be reflecting at least the same amount of light as Earth's moon does, and over a much larger area... the rings themselves would probably be a glowing band of light across the sky most nights.

Sometimes rings will have "shepherd" moons, small moons that orbit near the outer edges of rings or within gaps in the rings. The gravity of shepherd moons serves to maintain a sharply defined edge to the ring; material that drifts closer to the shepherd moon's orbit is either deflected back into the body of the ring, ejected from the system, or accreted onto the moon itself.

Maybe a number of small (think Phobos and Deimos) moons exist, and that's what caused the mostly-stable accretion of the rings in the first place...

 

[Mirage_Patrick]

Sounds great. Assuming an earth atmosphere, are the rings visible during the day? Or at night?

I'm imagining placing some cool monsters on one of those asteroids in the ring.

I would think they would be visable all the time...

 

[sukael]

Actually, a slight correction to my earlier statement... given that the 'local' rings would be in direct shadow at night, it would probably show up something like an arch with the middle cut out, with both sides getting light filtered in from the lit sides of the planet...

 

[Castellan]

Oooh, ref page. http://en.wikipedia.org/wiki/Planetary_ring

Always a *very* good place to get information.

So they'd probably be reflecting at least the same amount of light as Earth's moon does, and over a much larger area... the rings themselves would probably be a glowing band of light across the sky most nights.

The reflectivity of rings from below can be as high or as low as you want. Maybe they're even the source of magic on this world? Maybe they glow differently on different days?

Maybe a number of small (think Phobos and Deimos) moons exist, and that's what caused the mostly-stable accretion of the rings in the first place...

Shepherd moons. Yeah, there would possibly be some of these.

In reali life, a terrestrial planet wouldn't be too likely to have rings because of its size and mass limitations. Gas giants are more likely to have rings.

However, this isn't real life. Make up something that sounds good regarding the presence of the rings and go with it. You should have some great mythology to go along with this, too. Don't you think that people on this planet would look up, see the rings, and think that perhaps they're there to hold the sky up? Or maybe the rings are a pathway that the Dead take to the Afterlife? Perhaps the rings are where the gods live, and when there are meteor showers (bound to be a lot of these) it's because the gods are mad at those folks on the ground.

You could have adventures centered around other myths. The rings are made of Diamonds! Someone should go up there and harvest them to become rich! (Who knows... maybe they really ARE made of diamonds...)

Invariably, your PCs are going to want to travel up there. Commit another scientific sin and do away with the vacuum of space. As long as the players can find a way to fly that high, they can get there. No fly spell is going to last long enough, so they'll need to get creative. And no Giant Roc is going to be able to fly for that long (even if the distance isn't 1000 miles up -- and, honestly, I'd make it only 50 -100, unless you're going to have Cloud Giant castles, or somewhere else for the PCs to rest....).

Could be a lot of fun!

 

[Castellan]

Actually, a slight correction to my earlier statement... given that the 'local' rings would be in direct shadow at night, it would probably show up something like an arch with the middle cut out, with both sides getting light filtered in from the lit sides of the planet...

True... If this works, then use it. Otherwise, maybe it's in that darker space -- or during a solar eclipse (if the planet has such a thing) -- that people can see an "unnatural" glow...

 

[lukelightning]

Is there a ring around Uranus?