Is there an addon with the incomplete arcs in Neptune rings system?
Is there a support in Celestia code for such objects?
Thank you.
incomplete arcs in Neptune rings system
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granthutchison
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granthutchison
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- then we could build "lumpy" fresh debris rings, too.
The problem is not really to draw the arcs but to simulate their dynamics, which I think is not well understood and strongly influenced by Neptune's satellites and a little chaotic.
I was looking through the web to find if anyone has come up with a way to tell approximatively for each arc its position, length and thickness at a given time, but haven't found anything yet.
I was looking through the web to find if anyone has come up with a way to tell approximatively for each arc its position, length and thickness at a given time, but haven't found anything yet.
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granthutchison
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- Posts: 1863
- Joined: 21.11.2002
- With us: 22 years
In Solar System Dynamics, there's a description of how Porco reported that a 42:43 resonance with the moon Galatea would produce 42*2 = 84 corotating resonance sites in the Adams ring, each one 360/84 = 4.3 degrees long and 1.2 kilometres wide. Dust in the ring would circulate around these stable points. There are problems with the longterm dynamics of such a system, though.
Here is a paper modifying Porco's original theory so that dust is confined by kilometre-size bodies occupying just some of the resonance sites - improving the longterm stability of the system, and explaining why only some segments contain ring arcs. (In this model, the dust arcs are spread between resonances, rather than being centred on them.) The arcs themselves are ~15km in radial width, embedded in the diffuse Adams ring ~50km wide. Note added later: This paper predicts 86 resonance sites rather than the 84 given in Solar System Dynamics.
The layout of ring arcs (in fact, just dust concentrations within the continuous Adams ring) from Solar System Dynamics is as follows, from leading to trailing:
Courage arc (4.3 degrees, partially filled)
Empty arc (4.3 degrees)
Libert? arc (4.3 degrees)
Empty arcs (8.6 degrees)
Egalit? 1 (4.3 degrees, partially filled)
Egalit? 2 (4.3 degrees)
Empty arc (4.3 degrees)
Fraternit? arc (8.6 degrees, containing two neighbouring librating systems)
(The "empty arcs" contain no noticeable excess dust concentration, but do contain dust at the general background level of the Adams ring.)
To model such a system properly we'd need to be able to rotate the ring texture. Impossible to model more complex systems without being able to introduce several different ring systems, each with its own characteristic orbital period.
Grant
PS added after more reading: I've come back and removed misleading suggestions in my original post that the arcs move in synch with Galatea - in fact, there is a 30km radial "wave" of distortion which sweeps through the arcs in synch with Galatea. I assume that the mean motion of the arc particles must be at the local circular orbital velocity.
Here is a paper modifying Porco's original theory so that dust is confined by kilometre-size bodies occupying just some of the resonance sites - improving the longterm stability of the system, and explaining why only some segments contain ring arcs. (In this model, the dust arcs are spread between resonances, rather than being centred on them.) The arcs themselves are ~15km in radial width, embedded in the diffuse Adams ring ~50km wide. Note added later: This paper predicts 86 resonance sites rather than the 84 given in Solar System Dynamics.
The layout of ring arcs (in fact, just dust concentrations within the continuous Adams ring) from Solar System Dynamics is as follows, from leading to trailing:
Courage arc (4.3 degrees, partially filled)
Empty arc (4.3 degrees)
Libert? arc (4.3 degrees)
Empty arcs (8.6 degrees)
Egalit? 1 (4.3 degrees, partially filled)
Egalit? 2 (4.3 degrees)
Empty arc (4.3 degrees)
Fraternit? arc (8.6 degrees, containing two neighbouring librating systems)
(The "empty arcs" contain no noticeable excess dust concentration, but do contain dust at the general background level of the Adams ring.)
To model such a system properly we'd need to be able to rotate the ring texture. Impossible to model more complex systems without being able to introduce several different ring systems, each with its own characteristic orbital period.
Grant
PS added after more reading: I've come back and removed misleading suggestions in my original post that the arcs move in synch with Galatea - in fact, there is a 30km radial "wave" of distortion which sweeps through the arcs in synch with Galatea. I assume that the mean motion of the arc particles must be at the local circular orbital velocity.