1991/08/02 by G. W. Wetherill · 1 citation
Physics and Astronomy · #Astro and Planetary Science #Stellar, planetary, and galactic studies #Astrophysics and Star Formation Studies #Planet #Astrobiology #Terrestrial planet #Solar System #Asteroid #Merge (version control) #Physics #Astronomy
paper · doi:10.1126/science.253.5019.535
openalex publication_date 1991/08/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/23
Present theories of terrestrial planet formation predict the rapid ;;runaway formation'' of planetary embryos. The sizes of the embryos increase with heliocentric distance. These embryos then merge to form planets. In earlier Monte Carlo simulations of the merger of these embryos it was assumed that embryos did not form in the asteroid belt, but this assumption may not be valid. Simulations in which runaways were allowed to form in the asteroid belt show that, although the initial distributions of mass, energy, and angular momentum are different from those observed today, during the growth of the planets these distributions spontaneously evolve toward those observed, simply as a result of known solar system processes. Even when a large planet analogous to ;;Jupiter'' does not form, an Earth-sized planet is almost always found near Earth's heliocentric distance. These results suggest that occurrence of Earth-like planets may be a common feature of planetary systems.