Saturn's Rings Formed From Large Moon Destruction 115
Matt_dk writes "The formation of Saturn's rings has been one of the classical if not eternal questions in astronomy. But one researcher has provided a provocative new theory to answer that question. Robin Canup from the Southwest Research Institute has uncovered evidence that the rings came from a large, Titan-sized moon that was destroyed as it spiraled into a young Saturn."
Re:Isnt this kinda old news? (Score:4, Interesting)
The theory has been floated but this is the first time that I am aware that someone actually worked out the mechanics of it. It's not 'proof' but it's a lot better than just conjecture.
Disclaimer: I am not an astrophysicist or a planetary expert. It's possible that someone did work out the same thing in detail. If so I just haven't seen it.
ACC was right! (Score:5, Interesting)
In 2001, ACC pointed out the odd coincidence between the ring of Saturn being only 4 million years old, and the time when the Monolith appeared on Earth. Hmmmmmm.
BTW - The book has the large monolith at Saturn, not Jupiter. Kubrick was worried about the FX it would take to portray the rings on film, so they changed it to Jupiter.
New? (Score:3, Interesting)
Is this really a new theory? Or is this a new interpretation of an existing theory.
I recently read 2001, finally, and I'm fairly certain Arthur C. Clarke mentions Saturn's rings having been formed due to the destruction of a moon. He's not a scientist, but I'm fairly certain he got the idea from scientific circles.
Re:Moon Crashed into the Earth (Score:3, Interesting)
In the very distant future, it'll be flung out of orbit.
No, it won't. I'm not sure that's ever energetically possible, let along possible from an angular momentum, standpoint. The Moon will evolve away from Earth until it's around 90 Earth-radii away (it's around 62 right now) and then halt its motion when we're in the double-locked state, like Pluto and Charon. At that point, solar tides take over and slow the Earth down more (but slower) and shift the geosynchronous orbit outside of the Moon's position, at which time the Moon starts moving back toward the Earth. But this is about 50 billion years away, and...
However, this will be long after the Sun goes nova.
No, it won't. Unless our models of stellar evolution are way, way wrong, the Sun's not a candidate to explode in any way. It'll swell up and then shrink and cool into a white dwarf. It may or may not destroy Earth in the process. (Odds favor "destroy Earth", but models differ.)
Re:that's no moon! (Score:4, Interesting)
I am not an astronomer, but it is my understanding (mainly from Carl Sagan's "Pale Blue Dot") that the asteroids are more likely leftovers from the formation of the solar system that, when caught between the gravity of the sun and tidal forces from Jupiter never got the chance to accrete into a planet. So, rather than being a destroyed planet, they are a planet that never was.
I don't know if there has been any new data to confirm or refute that hypothesis, though.
Re:New? (Score:1, Interesting)
He's not a scientist, but I'm fairly certain he got the idea from scientific circles.
You should probably read more about Clarke or possibly redefine your idea of what a scientist is.
Everybody is missing the point (Score:5, Interesting)
Well, I read all the comments so far and nobody has discussed the actual new parts of the model. The novelty is that the destroyed moon is assumed to be differentiated (The heavy metal and rock fall to the core and the light ices stay on the surface.) and Saturn was in its very early stages, when it was hot and its atmosphere greatly distended. This means that as the moon spirals in toward Saturn, its icy mantle gets stripped off by tidal forces first. That makes a vast disk of icy material from which the inner icy moons and the ring system are formed. Since the denser rocky material at the core of the moon is less affected by tidal forces, it impacts the extended atmosphere of Saturn and gets swallowed up before it has a chance to contribute to the disk. This explains the composition of the rings and moons better than previous models.
The point is not that it was a moon. There was no collision. Takeaway point if tl;dr:
The rings were formed by tidal disruption of a moon with an icy mantle and a rocky core.