Soru

### Models of Gas Giant Formation

How gas giant planets, such as Jupiter and Saturn, formed from the protoplanetary disks of gas and dust surrounding young stars is a subject of ongoing debate among planetary scientists. Two models propose different mechanisms and timelines.

Model 1 (Core Accretion Model)
Planetesimals composed of rock and ice collide and merge over millions of years, building a solid core with a mass of approximately $10$ Earth masses ($M_{\oplus}$). Once this critical core mass is reached, its gravitational pull rapidly attracts and retains a massive envelope of hydrogen and helium gas from the surrounding protoplanetary disk. This process requires a relatively long period ($1$ to $10$ million years) to form a gas giant. It predicts that gas giants will have large, dense solid cores at their centers, and that their composition will be enriched in heavy elements compared to their host stars.

Model 2 (Disk Instability Model)
A massive protoplanetary disk undergoes rapid gravitational collapse due to localized instabilities. If a region of the disk is sufficiently cold and massive, it becomes unstable under its own gravity, directly collapsing into a self-gravitating planetary clump in a very short timeframe (around $10^3$ to $10^4$ years). Gas giant formation bypasses the slow growth of a solid core. This model predicts that gas giants form rapidly and may have small or nonexistent solid cores (consisting only of dust that settled to the center after collapse), and that their bulk composition closely matches the chemical makeup of the parent stellar nebula.

Directions: Match each planetary characteristic or prediction on the left with the model classification on the right that best describes it.