Akretsioonilist

Akretsioonilist is a term used in geology and planetary science to describe the process of accretion, which is the gradual growth of a celestial body by the accumulation of smaller particles. This process is fundamental to the formation of planets, moons, asteroids, and comets. During the early stages of a solar system's formation, vast clouds of gas and dust, known as nebulae, collapse under their own gravity. Within these nebulae, small particles begin to clump together due to electrostatic forces and then gravitational attraction.

As these clumps grow larger, they become planetesimals, which are bodies ranging in size from a few meters to hundreds of kilometers in diameter. These planetesimals continue to collide and merge, a process known as akretsioonilist growth. The material available for accretion is primarily determined by the composition of the protoplanetary disk from which the celestial bodies are forming. In the inner solar system, where temperatures were higher, rocky materials dominated, leading to the formation of terrestrial planets. Further out, in colder regions, volatile compounds like water, methane, and ammonia could condense, allowing for the formation of gas giants and ice giants with substantial outer envelopes. The rate of akretsioonilist can vary significantly depending on the density of material in the disk and the gravitational influence of existing large bodies. This process is not limited to initial formation; it can also occur through the capture of asteroids and comets by planets.