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View Full Version : Neptune and Triton; eventual ring system or collision?



Sanbeko
2009-Feb-27, 05:27 PM
I was doing some reading about ring systems and moons. There isn't as much data out there as I thought. Several sites stated that eventually Neptune's moon, Triton, would be pulled into the Roche limit and break up into a ring system. (It may have been a comet captured by Neptune, travels retrograde, etc) The reading material out there suggested that Triton could eventually crash into Neptune.

So, would Triton break up into a ring system first? Then the debris slowly be drawn closer, making for beautiful-albeit deadly-meteor showers? Do scientist's have any documentation of any moon's orbit deteriorating and impacting a planet?

Is this what will eventually happen with all ring systems made up of rocks (vs. say Saturns' rings which are mostly composed of ice?) Is there any documentation out there regarding chunks of ring systems colliding with their planets? Or are these systems too stable?

Thanks for letting me pick your brains,

Sanbeko

grant hutchison
2009-Feb-27, 05:51 PM
So, would Triton break up into a ring system first? Then the debris slowly be drawn closer, making for beautiful-albeit deadly-meteor showers?Triton is big enough that we can be sure it's held together gravitationally (rather than being one monolithic mass), so it's certainly going to fall apart in the Roche zone.
Ring systems behave as if they're a little viscous, so it's often stated that they'll have a life-span of just a few million years before they thin because of "leaks" at the ring edges. But there's been some suggestion recently that Saturn's rings might be very long-lived, dating back billions of years.


Do scientist's have any documentation of any moon's orbit deteriorating and impacting a planet?No. And we wouldn't really expect them to, since these are very rare occurrences.


Is this what will eventually happen with all ring systems made up of rocks (vs. say Saturns' rings which are mostly composed of ice?)Ice or rock shouldn't make much difference. The ring chunks interact gravitationally, in the main.


Is there any documentation out there regarding chunks of ring systems colliding with their planets? Or are these systems too stable?Ring systems are very deep in the gravity wells of their parent planets, so it would take a lot of energy to accelerate a ring particle to the point at which it left one planet and struck another.

Grant Hutchison

Sanbeko
2009-Feb-27, 06:14 PM
Interesting. Although when you said

'Ring systems are very deep in the gravity wells of their parent planets, so it would take a lot of energy to accelerate a ring particle to the point at which it left one planet and struck another.'

I think I didn't phrase my question properly. sorry. I thought perhaps the particles in the ring system would strike their parent planet's surfaces, not another planet.

Sanbeko

grant hutchison
2009-Feb-27, 06:30 PM
I think I didn't phrase my question properly. sorry. I thought perhaps the particles in the ring system would strike their parent planet's surfaces, not another planet.No, it was my mistake. You wrote "their planets", but I read it as "other planets". :sad:

Grant Hutchison

Sanbeko
2009-Feb-27, 07:48 PM
So is it possible that these larger pieces from a ring system could spiral into their parent planet's surface eventually?

Sanbeko

grant hutchison
2009-Feb-27, 10:35 PM
So is it possible that these larger pieces from a ring system could spiral into their parent planet's surface eventually?The dynamics of ring systems tends to make them spread: inner edge inwards, outer edge outwards. Even when there are "shepherd moons" maintaining sharp edges to the rings, the whole system tends to spread.
So I've seen it said that Saturn's C Ring extends all the way to the atmosphere, as particles rain out of the inner edge. I don't know if that's still the current view, or what the mass flux might be.

Grant Hutchison

agingjb
2009-Feb-28, 08:21 AM
The gradual decay of Triton's retrograde orbit might at some time create some interesting interactions with Proteus and the other inner moons, which are orbiting the conventional way.

Sanbeko
2009-Mar-01, 12:19 PM
Oh. Thanks for your input.

Sanbeko