Admittedly I’m asking with a lot of ignorance, so I’m not sure my question entirely makes sense. Gas giants in our solar system are just globs of gas, but all clumped up. However, various space photos, like the “Pillars of Creation” seem to be just floating blobs of gas that don’t seem to combine into a single spherical entity, planet or otherwise. Why does some float around and some clump into a single sphere? Or are the blobs floating around simply in transit from some stellar event and haven’t had time for its miniscule gravity to pull itself into ball?
In: Planetary Science
Gas Giants and nebulae such as the Pillars of Creation are on two different scales of sizes and time and nebulae eventually lead to planets. Planets are bits of matter that have, thanks to gravity, consolidated and compressed down into a much small, denser body. (Small being relative here.) Nebulae are massive clouds of gas that can span several light years wide, or even several hundred light years. The pillars are about 4-5 light years across. For comparison, the orbit of Pluto is about .001 light years in diameter and if we define the solar system as anything that orbits the Sun (which includes the Oort cloud that surrounds what we usually think of as the solar system), then the whole solar system is about 2 light years across.
The detail you are missing is time. Nebulae are star system factories, but it occurs over the course of over millions or even billions of years. Those clouds are not uniform in their density and clumps of gas exert gravity on surrounding gas, pulling things together. Over time, these dense pockets will collapse further, eventually forming stars. When a star forms, it will than push the remaining local gas away from itself. In turn, this left over gas will collapse over hundreds of millions of years in proto-planets and these combine into planets. Smaller planets will be rocky like earth, larger ones will be gaseous like Jupiter.
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