Accretion disk’s magnetic field controlled the composition of the terrestrial planetsOPEN ACCESS 

· by · in , , ,

William F McDonough, Takashi Yoshizaki

LINK (OPEN ACCESS)
PDF (DOWNLOAD)

“Chondrites, the building blocks of the terrestrial planets, have mass and atomic proportions of oxygen, iron, magnesium, and silicon totaling ≥90% and variable Mg/Si (∼25%), Fe/Si (factor of ≥2), and Fe/O (factor of ≥3). The Earth and terrestrial planets (Mercury, Venus, and Mars) are differentiated into three layers: a metallic core, a silicate shell (mantle and crust), and a volatile envelope of gases, ices, and, for the Earth, liquid water. Each layer has different dominant elements (e.g., increasing Fe content with depth and increasing oxygen content to the surface). What remains an unknown is to what degree did physical processes during nebular disk accretion versus those during post-nebular disk accretion (e.g., impact erosion) influence these final bulk compositions. Here we predict terrestrial planet compositions and show that their core mass fractions and uncompressed densities correlate with their heliocentric distance, and follow a simple model of the magnetic field strengthen the protoplanetary disk. Our model assesses the distribution of iron in terms of increasing oxidation state, aerodynamics, and a decreasing magnetic field strength outward from the Sun, leading to decreasing core size of the terrestrial planets with radial distance. This distribution would enhance habitability in our solar system, and would be equally applicable to exo-planetary systems.”

Related posts (automatically generated):

  1. Terrestrial planet compositions controlled by accretion disk magnetic fieldOPEN ACCESS 
  2. A pebble accretion model for the formation of the terrestrial planets in the Solar SystemOPEN ACCESS 
  3. Accretion and differentiation of the terrestrial planets with implications for the compositions of early-formed Solar System bodies and accretion of water
  4. The Effect of a Strong Pressure Bump in the Sun’s Natal Disk: Terrestrial Planet Formation via Planetesimal Accretion Rather than Pebble Accretion
  5. Isotopically distinct terrestrial planets via local accretion
  6. Common feedstocks of late accretion for the terrestrial planets
  7. Effects of pebble accretion on the growth and composition of planetesimals in the inner Solar SystemOPEN ACCESS 
  8. Terrestrial planet formation from lost inner solar system materialOPEN ACCESS 
  9. Dynamic evolution of major element chemistry in protoplanetary disks and its implications for Earth-enstatite chondrite connection
  10. A reassessment of the iron isotope composition of the Moon and its implications for accretion and differentiation of terrestrial planets
Tags: , , , ,