# Tag Info

### stability of two moons

I looked at this problem earlier. Clearly if the moons are tiny compared to the central body, you don't have a problem. With small moons, the forces between the two moons is very very small, and ...
• 10.5k
1 vote
Accepted

### Long-term stability for a terrestrial planet with rings and a large sub-synchronous moon

Plausibility of the scenario & options I have given the original idea more thought. I try to elaborate in the second part about the Roche limit. If you would like to have additional info, see this ...
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### Long-term stability for a terrestrial planet with rings and a large sub-synchronous moon

Prioritize moon orbit vs. size vs. rings I understand your intent, the goal is the optical effect of a large moon in the sky with the opportunity to have another ring some time in the future. But this ...
• 751
1 vote

### Long-term stability for a terrestrial planet with rings and a large sub-synchronous moon

A (recent!) comet-encounter caused the creation of the rings. Plausibility issues I agree with your assumption of the rings being prone do get ejected quickly because of the influence of the moon. But ...
• 751
Accepted

### What are the orbital perturbations needed to destabilize a system to the point of taking some bodies out of resonance and kicking out another?

I actually wrote a paper on almost this topic, as related to a specific exoplanet system (Trappist-1) with 7 planets in resonance (paper here, poem here). The question I addressed in that paper (...
• 3,529
1 vote

### Day-to-Night observable Sky on a Orbital (non-Niven, small ring)

All I could answer is that for certain each side will eclipse the other fully each day at noon on the side getting sunlight. I get the coin flip (to provide for day/night). Each side’s shadow will ...
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### Day-to-Night observable Sky on a Orbital (non-Niven, small ring)

What I understand from your description it's a Banks orbital. It's a structure much smaller than a ringworld and does not encircle the whole star. It spins like a wheel, not a coin, while at the same ...
• 6,329
Accepted

### Day-to-Night observable Sky on a Orbital (non-Niven, small ring)

Would the other inner edge of the ring be visible at all times? Yes, the other inner edge of the ring would be visible at all times, but it might look hazy due to the atmosphere, similar to how ...
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### What color would the sky be in a multi-star system?

Blue, Rayleigh Scattering is a function, primarily, of depth of atmosphere. There are a few gases, notably the various sulfur oxides, that can tint the atmosphere in high enough concentrations but ...
• 47.6k
Accepted

### Artificial Satellites Orbit Around a Cube with Uniform Surface Gravity

Although this answer may be incomplete, I considered a square star on a X-Y plane (not a cube) and ignore rotation. To create a gravitational potential that is as square as possible, I arranged a ...
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### What are the size limits on an spin-gravity space station?

The hoop stress on a rotating ring is proportional to the square of the tangential velocity at the edge, according to the formula I have found there. So for a thin ring maximum tangential velocity is \$...
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### How would a cube-moon orbit a Cube-World with uniform surface gravity?

The mass distribution will affect either body, but only to a small margin not enough to change the orbit's shape visibly In fact, what we calculate as gravity force is actually an integral by volume ...
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