According to the nebular theory, the planets formed from a process called <u>accretion</u>.
Explanation:
The nebular theory is a theory that explains the formation of solar systems. After the formation and growth of the proto-star, the gases and dust in the nebula form a disk and spiral quickly around its center under the influence of its gravitation. This long and destructive process ends with the formation of planets, characteristics of which depend on their distance from the star. The term from astrophysics referring to this way of planet formation is <em>accretion</em>. Planets are not only astronomical objects created by accretion processes but galaxies and stars as well.
