proto-Earth Archives

The element abundances in the silicate Earth can be modelled as the result of accretion of three distinct components with distinct element abundances and isotope composition: A: a strongly volatile element depleted and reduced proto-Earth, B: a moderately volatile depleted and more oxidized Moon-forming impactor (Theia) and C: a near chondritic and oxidized late veneer. The absolute abundance of the siderophile and chalcophile elements was modified by core formation following accretion (after Mezger et al., 2021). -- astro-ph.EP

Astrochemistry, Astrogeology, Comets and Asteroids, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Lava / magma ocean / Volcanic Worlds, Meteorites & Asteroids, Status Report, Water/Hycean Worlds & Oceanography

From Dust to Planets — A Chemical Perspective

by Keith CowingApril 20, 2026April 20, 2026

Chemical and chronological information preserved in meteorites permits the reconstruction of events and processes in the solar nebula from the formation of the first solids to the accretion of planetary […]

Optical image of the clastic matrix region in LAR 12252 that was studied using S-XANES. Notable phases include enstatite (example outlined in red), sulphides (example outlined in yellow), a small chondrule fragment (outlined in orange), and fine matrix (example highlighted in pink). b Corresponding map calculated from the SXANES spectra of the region shown in a, showing the amplitude of the H-S peak at each point normalised to the average amplitude of point spectra measured from chondrule mesostasis. Black pixels correspond to points where the S-XANES spectra that did not contain a resolvable H-S peak. White pixels correspond to points where the SXANES spectra could not be fitted due to their quality or noise in the spectra. -- astro-ph.EP

Astrochemistry, Astrogeology, Biogeochemical Cycles & Geobiology, Comets and Asteroids, Meteorites & Asteroids, Status Report, Water/Hycean Worlds & Oceanography

The Source of Hydrogen in Earth’s Building Blocks

by Keith CowingJune 21, 2024June 21, 2024

Despite being pivotal to the habitability of our planet, the process by which Earth gained its present-day hydrogen budget is unclear. Due to their isotopic similarity to terrestrial rocks across […]