What is the process of accretion in the formation of solar systems?

Accretion is the process of particles coming together to form larger bodies in the formation of solar systems.

During the formation of a solar system, a cloud of gas and dust begins to collapse under its own gravity. As the cloud collapses, it begins to spin, forming a protoplanetary disk. The particles in the disk begin to collide and stick together, forming larger and larger bodies called planetesimals. These planetesimals continue to collide and grow, eventually forming planets.

Accretion can occur through two main processes: collisional and gravitational. In collisional accretion, particles collide and stick together due to electrostatic forces. In gravitational accretion, particles are drawn together by their mutual gravitational attraction.

The rate of accretion depends on a number of factors, including the size and density of the particles, the temperature and pressure of the disk, and the distance from the central star. In some cases, the accretion process can be disrupted by the presence of large gas giants, which can scatter smaller bodies and prevent them from accreting into larger planets.

Overall, accretion is a crucial process in the formation of solar systems, allowing small particles to come together and form the planets and other bodies that make up our solar system today.