What problems does the granulation tack model of the early solar system evolution attempt to explain
The granulation tack model of early solar system evolution attempts to explain the following problems:
1. Why were the inner and outer planets so different in composition?
2. Why are there asteroid belts between the terrestrial and Jovian planets?
3. Why are there large gas giants in the outer part of the solar system but no gas giants in the inner part?
4. Why are there relatively few small bodies in the outer solar system compared to the inner solar system?
5. How did the giant planets form and migrate to their current positions?
6. How did the early solar wind affect the formation and evolution of the solar system?
The granulation tack model of the early solar system evolution attempts to explain several problems related to the formation of terrestrial planets. Here are some of the problems it addresses:
1. Differentiation: The granulation tack model explains how terrestrial planets, such as Earth, formed through a process known as differentiation. It suggests that initially, the protoplanetary disk was composed of solid rocky and metallic particles. Over time, these particles clumped together to form larger bodies, called planetesimals. Through collisions and subsequent gravitational interactions, these planetesimals underwent differentiation, with heavier materials like iron sinking to the core and lighter materials forming a rocky mantle and crust.
2. Variations in elemental abundances: The model also addresses the variations in elemental abundances in the terrestrial planets. It proposes that during the formation of planetesimals, certain elements would have condensed and become enriched in specific regions due to their different melting points and chemical affinities. This process, known as fractionation, resulted in the differentiation of these elements among the final planets.
3. Late veneer: The granulation tack model also explains the presence of certain volatile elements and isotopic anomalies observed in terrestrial planets. It suggests that after the initial formation of the planets, a late delivery of materials, called the late veneer, occurred. This late veneer would have brought volatile elements, such as water and carbon, to the planets, as well as isotopic anomalies observed in some rocks. This late delivery is thought to have happened through impacts of comets, asteroids, and other small bodies.
4. Accretion timescales: Finally, the granulation tack model proposes a mechanism to explain the relatively short timescales on which terrestrial planets formed. It suggests that the planetesimal accretion process was efficient and rapid, enabling the growth from small kilometer-sized bodies to planets several thousand kilometers in diameter within a few million years.
Overall, the granulation tack model aims to provide a comprehensive explanation for the formation of terrestrial planets, addressing the differentiation process, variations in abundances, late veneer, and accretion timescales.