2015/03/25 by Anders Johansen, Mordecai‐Mark Mac Low, Johansen, Anders +5 · 8 citations
Environmental Science · Physics and Astronomy · #Astro and Planetary Science #Astrophysics and Star Formation Studies #Earth and Planetary Astrophysics (astro-ph.EP) #FOS: Physical sciences #Isotope Analysis in Ecology #Planetary Science and Exploration
paper · pdf · doi:10.48550/arxiv.1503.07347
openalex publication_date 2015/03/25 · openalex created_date 2022/10/03 · openalex updated_date 2026/07/28
Chondrules are millimeter-sized spherules that dominate primitive meteorites\n(chondrites) originating from the asteroid belt. The incorporation of\nchondrules into asteroidal bodies must be an important step in planet\nformation, but the mechanism is not understood. We show that the main growth of\nasteroids can result from gas-drag-assisted accretion of chondrules. The\nlargest planetesimals of a population with a characteristic radius of 100 km\nundergo run-away accretion of chondrules within ~3 Myr, forming planetary\nembryos up to Mars sizes along with smaller asteroids whose size distribution\nmatches that of main belt asteroids. The aerodynamical accretion leads to\nsize-sorting of chondrules consistent with chondrites. Accretion of mm-sized\nchondrules and ice particles drives the growth of planetesimals beyond the ice\nline as well, but the growth time increases above the disk life time outside of\n25 AU. The contribution of direct planetesimal accretion to the growth of both\nasteroids and Kuiper belt objects is minor. In contrast, planetesimal accretion\nand chondrule accretion play more equal roles for the formation of Moon-sized\nembryos in the terrestrial planet formation region. These embryos are isolated\nfrom each other and accrete planetesimals only at a low rate. However, the\ncontinued accretion of chondrules destabilizes the oligarchic configuration and\nleads to the formation of Mars-sized embryos and terrestrial planets by a\ncombination of direct chondrule accretion and giant impacts.\n