Draft:Disk instability model

The disk instability model (DIM) is one of the two leading theories for the formation of giant planets, alongside the core accretion model. It proposes that massive protoplanetary disks, which are disks of gas and dust surrounding young stars, can fragment into gravitationally bound clumps that eventually become giant planets.

Formation
The formation of a massive protoplanetary disk begins with the aggregation of material, resulting in a disk roughly 10-20 times the mass of the minimum-mass solar nebula. Primarily composed of gas with interspersed dust and ice grains, the disk undergoes a process of rapid cooling as it ages, facilitated by efficient heat radiation from dust grains. This cooling, in turn, increases the density of the disk, making it susceptible to gravitational instabilities that manifest as spiral arms within the disk. These arms may fragment into denser clumps of gas and dust, which, if sufficiently massive, become gravitationally bound and undergo collapse. During this collapse, the clumps heat up and condense, eventually accreting surrounding gas to form planetary cores. These cores continue to grow by accumulating gas from the disk until they mature into giant planets, completing the process of giant planet formation within the protoplanetary disk.