system
Given the following post, respond as if you're commenting on Reddit:
human
Gas moons?

Is it posible for planets to have gas moons?      
And a follow-up question: How small can a gas planet/moon be? - *the smalest gas spheres?*
gpt
A gas moon at any radius will experience tidal deformation-- basically the planet's gravity pulls more strongly on one side of the gas moon than on the other, stretching it out-- which will cause it to rapidly spiral in and be ripped apart.

Besides that, it is very difficult to set up a scenario in which a gas moon could form. Put large amounts of gas around a planet and it will either be blown away by the solar wind or captured by the planet faster than it can coalesce into any decent-sized object. Generally, small amounts of gas do not have enough mass to hold them together against their kinetic velocities.

In short, gas moons are not at all likely.