<p>Most of Saturn's rings are inside it's <a href="https://en.wikipedia.org/wiki/Roche_limit" rel="nofollow noreferrer">Roche limit</a>, which means they will never clump together.   Tidal forces prevent this from happening.</p>

<p>small objects that are already together can withstand the tidal forces.    A sufficiently large body inside a planet's Roche limit should break apart by tidal forces.   That may be how the rings formed in the first place, or they may have formed by collision.</p>

<p><a href="https://solarsystem.nasa.gov/news/813/nasas-cassini-data-show-saturns-rings-relatively-new/" rel="nofollow noreferrer">Saturn's rings are thought to be relatively young</a>, if 100 million years qualifies as young, but it is for objects inside the solar system.    Being young doesn't tell us how long they will last.   I think the <a href="https://www.nasa.gov/press-release/goddard/2018/ring-rain" rel="nofollow noreferrer">300 million year estimate</a> may be accurate enough, originally mentioned in the comments, but until that happens, the rings will remain, just grow smaller over time and they'll never coalesce into moons.  </p>

<p>As a footnote, Saturn's thinner outer rings or gossamer rings are outside the Roche limit, and those might, one day, form into moons, or they may be too thin for that to happen.  A certain density is probably required for moon formation.</p>

CC BY-SA 4.0
2020-01-27T23:30:06.363Z
There is also the contrary position, namely that the Rings are very old (https://ui.adsabs.harvard.edu/abs/2012Sci...338.1196C/abstract ). I don't think the debate is settled.
AtmosphericPrisonEscape
CC BY-SA 4.0
2020-01-27T22:50:01.400Z
2020-01-27T22:50:01.400Z
userLTK
<p>Saturn's rings contain <a href="https://en.wikipedia.org/wiki/Moonlet" rel="nofollow noreferrer">many moonlets</a> that shape the rings of Saturn. The structures in the rings of Saturn around moonlets are similar to those in protoplanetary disks around newly formed planets, which makes me wonder if the material in the rings will follow a similar fate and form into larger bodies. </p>

<p>Will the material within the rings of Saturn eventually coalesce into moons, or are the rings of Saturn stable enough to last billions of years?</p>

CC BY-SA 4.0
2020-01-27T16:25:37.067Z
https://www.nasa.gov/press-release/goddard/2018/ring-rain says 100 million years.
PM 2Ring
CC BY-SA 4.0
2020-01-27T17:49:44.923Z
@PM2Ring Those results are highly debated.
AtmosphericPrisonEscape
CC BY-SA 4.0
2020-01-27T18:04:52.830Z
@AtmosphericPrisonEscape Oh, ok. That same article also mentions a maximum lifespan of 300 million years. But I suppose an actual answer to the OP's question needs to mention that the rings are inside Saturn's Roche limit...
PM 2Ring
CC BY-SA 4.0
2020-01-27T20:40:31.727Z
There's some minor "clearing" of portions of rings due to slightly larger rocks orbiting within the ring.
Carl Witthoft
<saturn-rings><moonlet>
Are Saturn's rings stable?
usernumber
# Are Saturn's rings stable?

(Asked by: username_0 on 2020-01-27)

Saturn's rings contain [many moonlets](https://en.wikipedia.org/wiki/Moonlet) that shape the rings of Saturn. The structures in the rings of Saturn around moonlets are similar to those in protoplanetary disks around newly formed planets, which makes me wonder if the material in the rings will follow a similar fate and form into larger bodies.

Will the material within the rings of Saturn eventually coalesce into moons, or are the rings of Saturn stable enough to last billions of years?

**Tags:** saturn-rings, moonlet

> **Comments:**
> **username_1**: https://www.nasa.gov/press-release/goddard/2018/ring-rain says 100 million years.  
> **username_2**: @PM2Ring Those results are highly debated.  
> **username_1**: @username_2 Oh, ok. That same article also mentions a maximum lifespan of 300 million years. But I suppose an actual answer to the OP's question needs to mention that the rings are inside Saturn's Roche limit...  
> **username_3**: There's some minor "clearing" of portions of rings due to slightly larger rocks orbiting within the ring.  

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## 1 answers

### Answer by username_4 on 2020-01-27. Score: 3 | Accepted answer

Most of Saturn's rings are inside it's [Roche limit](https://en.wikipedia.org/wiki/Roche_limit), which means they will never clump together. Tidal forces prevent this from happening.

small objects that are already together can withstand the tidal forces. A sufficiently large body inside a planet's Roche limit should break apart by tidal forces. That may be how the rings formed in the first place, or they may have formed by collision.

[Saturn's rings are thought to be relatively young](https://solarsystem.nasa.gov/news/813/nasas-cassini-data-show-saturns-rings-relatively-new/), if 100 million years qualifies as young, but it is for objects inside the solar system. Being young doesn't tell us how long they will last. I think the [300 million year estimate](https://www.nasa.gov/press-release/goddard/2018/ring-rain) may be accurate enough, originally mentioned in the comments, but until that happens, the rings will remain, just grow smaller over time and they'll never coalesce into moons.

As a footnote, Saturn's thinner outer rings or gossamer rings are outside the Roche limit, and those might, one day, form into moons, or they may be too thin for that to happen. A certain density is probably required for moon formation.

> **Comments:**
> **username_2**: There is also the contrary position, namely that the Rings are very old (https://ui.adsabs.harvard.edu/abs/2012Sci...338.1196C/abstract ). I don't think the debate is settled.  

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