Protoplanetaarsest

Protoplanetaarsest refers to a protoplanetary disk, which is a rotating, circumstellar disk of dense gas and dust that surrounds a young, newly formed star. These disks are the birthplaces of planets. The material within a protoplanetary disk is leftover from the star's formation process, a consequence of the gravitational collapse of a giant molecular cloud. These disks can be quite massive, containing enough material to form several planets.

The process of planet formation within a protoplanetary disk begins with accretion. Dust grains within the disk collide and stick together, gradually growing into larger objects called planetesimals. These planetesimals, in turn, collide and merge, eventually forming protoplanets. Over millions of years, these protoplanets continue to accumulate material, evolving into the planets we observe today. The composition and structure of a protoplanetary disk vary with distance from the central star. Closer to the star, temperatures are higher, allowing only rocky materials to condense, leading to the formation of terrestrial planets. Further out, where temperatures are lower, volatile compounds like water and methane can also condense, enabling the formation of gas giants and ice giants. The study of protoplanetary disks provides crucial insights into the origins and diversity of planetary systems, including our own.