Gas in outer space cannot create enough mutual gravity to 'clump' together.
Yes, it can. Because every last atom, every particle, every dust grain, has a gravitational field.
Given enough time, even gas clumps. A few molecules finally get close enough to stick together, and you've got a tiny dust grain. It has a little more gravity than a lone molecule. It attracts a few more molecules until they're finally close enough to chemically bond. The grain gets bigger. It serves as a seed. It attracts more dust grains and more gas molecules.
This happens trillions and trillions of times over throughout both the largest and smallest molecular clouds. It serves to create places where gases are denser. Shockwaves from stellar explosions and the pressure of radiation from distant stars helps to push them closer together, too, creating even denser regions. The second you have a dense region in a molecular cloud, it starts to collapse under its own gravity and pull in dust and gas from around it. It may take it a million years or more, but it doesn't matter, because it's not punching a human time clock--it has all the time it needs. Unless something happens to physically prevent it, it will eventually roll itself up into a progressively denser and denser ball until the heat generated by its own gravitational compression forces it to begin nuclear fusion.
I've never seen 'balls' of fog.
Gas molecules in the vacuum of space do not act exactly like clouds in an atmosphere.
Gas clouds in outer space expand... they do not contract.
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