Illustration of Terrestrial Planet Formation

A simplified view of the classical model for terrestrial planet formation (not to scale). From top to bottom: The central star is surrounded by nebular gas and dust where early solids form. In the next stage, nebular gas begins to dissipate over 2–3 million years (Williams & Cieza 2011), and mass accumulates into fewer and larger bodies, forming planetary embryos. Next, the orbits of the planetary embryos cross each other and lead to giant impacts such as that illustrated in the inset. After tens to hundreds of millions of years of giant impacts, the terrestrial planets achieve a stable architecture (for a review, see Raymond & Morbidelli 2022) (see

Section 3).

This image is Figure 1 in Gabriel & Cambioni (2023) adapted from Levin (1972); image courtesy of Andrew Gonzalez.