# moonlet vs moon

**URL:** <https://boards.straightdope.com/t/moonlet-vs-moon/784672>\
**Category:** Factual Questions\
**Created:** [April 17, 2017, 10:09pm UTC](https://boards.straightdope.com/t/moonlet-vs-moon/784672 "2017-04-17T22:09:25Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\
**Post date:** [April 17, 2017, 10:09pm UTC](https://boards.straightdope.com/t/moonlet-vs-moon/784672/1 "2017-04-17T22:09:25Z")

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> **[Moons of Saturn](https://en.wikipedia.org/wiki/Moons_of_Saturn)**
>
> The moons of Saturn are numerous and diverse, ranging from tiny moonlets only tens of meters across to the enormous Titan, which is larger than the planet Mercury. There are 83 moons with confirmed orbits as of 2023\[update\]. This number does not include the many thousands of moonlets embedded within its dense rings, nor hundreds of possible kilometer-sized distant moons that were only briefly captured by telescopes. Seven Saturnian moons are large enough to have collapsed into a relax Twenty-fo...

sez that:\* Saturn has 62 moons with confirmed orbits, 53 of which have names and only 13 of which have diameters larger than 50 kilometers\*

but later talks about "moonlets.  
But Aegaeon is tiny, hardly larger than the largest “moonlet”.

Have they defined what is a moon vs a “moonlet”?

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**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\
**Post date:** [April 17, 2017, 10:18pm UTC](https://boards.straightdope.com/t/moonlet-vs-moon/784672/2 "2017-04-17T22:18:21Z")

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Wiki [Moonlet - Wikipedia](https://en.wikipedia.org/wiki/Moonlet) sez amongst other things that moons embedded in ring systems are called moonlets. As are moons of moons and moons of asteroids. It seems the Saturnian stuff fits the first definition.

I have no clue what IAU says on the topic. The wiki article’s cites were to examples of usage, not to an official glossary.

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**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\
**Post date:** [April 17, 2017, 11:54pm UTC](https://boards.straightdope.com/t/moonlet-vs-moon/784672/3 "2017-04-17T23:54:07Z")

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The IAU has not defined moonlet or moon and they aren’t going to any time soon. Probably never will. Use the terms however you want.