Dust belt around Saturn

Not at all. Please explain yourself?

 

Log in or Sign up to hide all adverts.

What Physics Teachers Get Wrong About Tides!

 

Log in or Sign up to hide all adverts.

Our satellites are not big enough to experience any significant gravity differential across them. Same way we, standing, on the surface of the Earth do not notice it. Even though it is there.

Gravity falls off with the square of the distance. Your extra 1.8m on the surface doesn't make much difference to the 6370km radius of the Earth.

 

Log in or Sign up to hide all adverts.

More pertinent is the enormous distance between the objects in the belt. (Truly astronomical!) The gravitational attraction between them is miniscule and more than offset by the differential velocities.

 

Good.

Great to see some "weeding" being done in the serious science sections, to keep the quality of discussion at a tolerable level.

 

Excellent video Boris!

 

Last I checked, Saturn's rings are expected to only last a few hundred thousand years or so.
i.e. we are very fortunate to be alive to witness this relatively fleeting astronomical event.

I'm not sure exactly where they will go - probably fall into Saturn over time.

The Kuiper Belt is way way too rarefied to coalesce. The bodies in the belt are both too small and too far apart to have anything but a vanishinlgy small effect on each other. Without a significant attraction within the belt, the bodies will not coalesce in any reasonable timeline, if ever.

 

The Roche limit pertains to bodies where gravity is the dominate force defining their shape. In other words, objects both massive and flexible enough for their own gravity to pull them into a spherical shape. This is not true for satellites or the Space station where its is the molecular bounds of its material structure that dominates.

Also, the Roche Limit is not a single fixed distance. It depends on the relative density of the planet being orbited and the satellite. Saturn has a fairly low density and Earth has the highest density of all the planets. As a result, the Earth could easily orbit at a distance equal to Saturn's rings without being torn apart by tidal forces where a body of a lower density could not. But the rings start out with a low density, and thus can't coalesce.

 

I did mention the Shepherd moons in post 2, but I believe they only add stability to one of the rings.Prometheus and Pandora are the two moons....
I also am sure I have read somewhere where the rings are not stable, although I draw the line at Dave's "few hundred thousand years"
Out of interest one of Mars moons, is destined to be torn apart when it enters its Roche limit, and also Neptune's moon Triton, but I'm sure its over many millions of years time frame.

 

Please Register or Log in to view the hidden image!

Half right anyway!

Please Register or Log in to view the hidden image!

https://www.rt.com/news/323192-phobos-moon-mars-rings/
It may take millions of years, but Mars will likely one day become the fifth ringed planet in our solar system.The Red Planet, scientists have calculated, will crush its small moon Phobos with the force of its own gravity, leaving just a belt of debris in orbit.

http://www.astronomycafe.net/qadir/ask/a10513.html
Will Triton someday crash into Neptune because it rotates backwards?
Nope,In the 1980's some astronomers predicted that Triton would be pulled ever closer to Neptune until, in 100 million years, it would be torn apart to form a ring around Neptune. But Voyager measurements of the gravitational field of Neptune show that its tidal influence on Triton is no longer great enough to cause the satellite's orbit to shrink quite this fast. Computer modeling of the orbit by astronomer C. F. Chyba ( 1989, Astronomy and Astrophysics, vol. 219, p. L23) now show it shrinking from its present 14.3x Neptune's radius to only 12.5 times Neptune's radius, and taking over 5 BILLION years to do so. Triton, given the evolution of the Sun into a red giant, will outlast the Earth.

 

Yeah. My knowledge may be hopelessly outdated.

 

So was mine re Triton!

Please Register or Log in to view the hidden image!