SOLAR SYSTEM

Detailed explanation-1: -What is accretion theory? Accretion theory explains the process of small clumps of dust gathering together to gradually form planetesimals. These planetesimals accumulate more materials and form protoplanets. These protoplanets build until they form planets within the solar system.

Detailed explanation-2: -The prevailing model for planetary accretion, also called fractal assembly, and dating back as far as the 18th century, assumes that the Solar System’s planets grew as small grains colliding chaotically, coalescing into bigger ones, colliding yet more until they formed planetesimals.

Detailed explanation-3: -In astrophysics, accretion is the accumulation of particles into a massive object by gravitationally attracting more matter, typically gaseous matter, in an accretion disk. Most astronomical objects, such as galaxies, stars, and planets, are formed by accretion processes.