Saturn's moons could be constantly reforming

[Brian G Turner]

Computer models suggest Saturn's moons cannot be primarily responsible for creating Saturn's rings - and additionally, that the moons are likely to be constantly reforming:

Saturn’s moons could reassemble after a cosmic smash-up

 

[Vertigo]

That's interesting I've always had a problem with this idea in a couple of SF books I've written that have a moon that's been 'blown up' and spreads out to form a ring around the planet. It seems to me that unless the pieces have been blown away from the centre of gravity at greater than the escape velocity for the entire mass* they will simply pull themselves back together again. And that seems to be what that article is saying would happen.


*Even if it's not in one solid lump the pieces still have an aggregate mass and a centre of gravity for that mass.

 

[Brian G Turner]

That immediately puts me in mind of the hypothetical Phaeton - a planet that existed between Mars and Jupiter, but was destroyed, resulting in the asteroid belt there.

While there are claims that there isn't enough mass in the asteroid belt to constitute a planet, if there was a planet there but another significant mass - ie, another planet - collided with it, I wonder if it's theoretically possible for much of their combined mass to slingshot out from that event. Additionally, I wonder if momentum would result in the largest resulting mass from that continuing away from that orbit.

Than in itself would still be empty conjecture. And yet, NASA have just brought forward a mission to Philae from 2023 to 2022. Philae is an asteroid in the Mars-Jupiter asteroid belt that accounts for 20% of its mass. Almost completely solid iron, it has been suggested that it's the remains of a planetary core...

Perhaps future models of the solar system might one day include Phaeton.

 

[EJDeBrun]

I'm actually using this kind of concept for my WIP. It all depends on the size of the pieces after impact and also if there is critical mass loss that would prevent them from reforming into a orbital satellite. Over the millennia, additional cosmic accident can cause permanent loss to also prevent the planet from reforming.

If we could ever mine the stuff, we'd be able to figure it out. Who knows!

It's interesting stuff to work with.

 

[Brian G Turner]

As an interesting follow-up to this, I just found an old article that mentions that Saturn's moons went through a big shuffle only around 100 mya: Moons of Saturn may be younger than the dinosaurs – Astronomy Now