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Saturn is a gas giant like Jupiter. It has everything from

tiny moonlets less than 1 kilometer across to the enormous Titan, which is larger than the planet Mercury. Saturn has 62 moons with confirmed orbits.
Wikipedia

Why does Saturn have more moons?

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    $\begingroup$ According to solarsystem.nasa.gov/planets/jupiter Jupiter has 50 confirmed moons and 17 unconfirmed moons, whereas solarsystem.nasa.gov/planets/saturn Saturn has 53 known moons with 9 moons awaiting confirmation. So Saturn leads in confirmed moons, Jupiter leads in total moons including unconfirmed ones. $\endgroup$
    – user21
    Jan 29, 2016 at 17:29
  • $\begingroup$ Welcome and +1. $\endgroup$
    – Dumbledore
    Jan 29, 2016 at 17:31
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    $\begingroup$ But it doesn't have far more moons than other planets (notably Jupiter). The question needs rephrasing. $\endgroup$
    – ProfRob
    Oct 19, 2023 at 19:14

2 Answers 2

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Saturn and Jupiter have many moons for quite a few reasons, one of the main ones being that they have an absolutely immense gravitational pull. During the early stages of the formation of our solar system, there would of been many planet-like objects floating around which our gas giants would have attracted. Furthermore, these planets are so far out in the solar system water would if frozen (which explains Saturn's rings of ice). Infact, we can show that the ice can form moons by looking at some of the moons of Uranus, some of them are half made of ice!

A few of the outer moons of our planets are captured asteroids. Phoebe, which is a moon of Saturn, is believed to have been a captured asteroid.

I haven't heard anything about Saturn having more moons than jupiter.

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  • $\begingroup$ Considering your last statement, it's actually the other way round. Saturns rings evolve dynamically over time and must spread out beyond the Roche limit. They thus would deliver material to the outer region where it can coalesce into moons or at least accrete onto them. $\endgroup$ Jan 29, 2016 at 15:53
  • $\begingroup$ Ah! Thank You for letting me know, I didn't presume that would be the case. I'll edit out the statement, seen as it's false. $\endgroup$ Jan 29, 2016 at 16:47
  • $\begingroup$ Also, Uranus has 27 known moons and Neptune 14, so it's not as if they are lacking in moons either. $\endgroup$ Feb 2, 2016 at 16:32
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We are familiar with the way we classify our solar system planets, terrestrials and gas giants or Jovians.

  1. Now, both of them had a very different childhood. They even changed their orbital distance! Jupiter and Saturn used to be much, much closer to the Sun, almost where Earth and Mars are located. Jupiter's formation opened a gap in the planetary disk, which separated the planetesimals into two regions. When Jupiter and Saturn got interlocked in planetary resonance, only then did they start moving outward (that also gave the opportunity for the inner planets to form in the first place), which we call Planet Migration. They also even drifted apart from each other.
  2. The massive size of Jupiter and Saturn were influential in sweeping up matter in the Jovian disk and also in capturing other planetesimals from outer but eccentric orbits. The movement of Saturn to the more outer region caused it to sweep much more matter than Jupiter, which had a limited supply.
  3. Saturn kept capturing planetesimals and forming moons. Some of its moons also came too close to the planet (specifically at the Roche limit of the planet) and got tidally stripped of their mantle, which formed the rings.
  4. Neptune and Uranus formed later, so they didn't have much matter left in the disk because of both high solar winds stripping the planetary disk with matter, and Jupiter & Saturn sweeping up matter too. And that could be a plausible reason why Neptune and Uranus have lesser moons (lower mass than other Jovians and less matter to accreate).

This is, of course, a very basic picture, and the reality is much more complicated, especially when you throw in dynamical friction, turbulence, gas stripping, magnetohydrodynamics, etc. But I hope this will be enough to get the basic idea.

Feel free to comment if you have any doubts.

Edit: Here are some references which I used to get the perspective of this.

The last reference shows a different but prevailing theory.

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    $\begingroup$ Excellent answer!. Just 1 doubt: What does the sentence "the movement of Saturn to the more outer region caused it to sweep much more matter than Jupiter, which had a limited supply." mean?. According to my understanding of your answer I think you are referring that since Saturn is less massive than Jupiter, it would require less force for migration and therefore according to the grand tack hypothesis, it covered a larger area in the type I/runaway migration it has taken, due to this it virtually sweeps and captured moons from a larger area. Am I right and are there any other influential fact? $\endgroup$
    – Arjun
    Oct 25, 2023 at 12:05
  • $\begingroup$ Thanks a lot, and as @PM2Ring said, Can you please provide source/references for the answer? $\endgroup$
    – Arjun
    Oct 25, 2023 at 12:06
  • $\begingroup$ Your answer could be improved with additional supporting information. Please edit to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers in the help center. $\endgroup$
    – Community Bot
    Oct 26, 2023 at 1:12
  • $\begingroup$ Hey, @Arjun, I've added references for you. Also, your understanding is correct. $\endgroup$ Oct 27, 2023 at 7:45
  • $\begingroup$ @BhaveshRajpoot Thanks a lot!! $\endgroup$
    – Arjun
    Oct 27, 2023 at 12:04

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