astonomer think planets formed from interstellar dust and gased that clumped together in a process is called what?
Astronomers believe that planets formed from interstellar dust and gas that clumped together in a process called "accretion."
To understand this process, we need to explain it step by step:
1. Interstellar dust and gas: In space, there are vast clouds of dust and gas, known as nebulae. These nebulae consist of various elements and particles, such as hydrogen, helium, and heavier elements like carbon, oxygen, and iron.
2. Gravitational collapse: Due to gravity, these nebulae can undergo a process called gravitational collapse. As the nebula contracts under its own gravity, it starts to spin faster, forming a rotating disk-shaped structure called a protoplanetary disk.
3. Accretion: Within this protoplanetary disk, particles of dust and gas begin to collide and clump together through a process known as accretion. Initially, very small particles collide and stick together, forming larger particles called planetesimals. Over time, these planetesimals continue to collide and merge, growing in size.
4. Protoplanet formation: As accretion continues, larger and larger bodies called protoplanets form. These protoplanets have enough mass and gravitational pull to attract even more material from the protoplanetary disk, including gas, dust, and other planetesimals.
5. Planetary formation: Eventually, through further growth and accumulation, these protoplanets become fully formed planets. The specific processes and conditions for planetary formation vary based on factors such as the distance from the central star, temperature, and composition of the protoplanetary disk.
Therefore, astronomers believe that the process by which planets form from interstellar dust and gas clumping together within a protoplanetary disk is called "accretion."