Editorial: Topical Collection to “Reading Terrestrial Planet Evolution in Isotopes and Element Measurements”

Terrestrial planets evolve from primitive material of which remnants are now found in primitive meteorites called chondrites that originated from parent bodies that did not go through the cycle of melting and differentiation. Two broad categories have been defined based on their elemental and isotopic abundances, the carbonaceous chondrites (CC) and the non-carbonaceous chondrites (NC). Using geochemical observations of noble gases and other major volatiles, one can determine what the present-day inventory tells us on its initial building blocks, their sources, accretion processes and the early differentiation of planetary bodies such as the Earth. While many of the present-day volatile reservoirs have chondritic isotopic ratios, their relative abundances are certainly not chondritic, suggesting volatile losses from planetary embryos and growing proto- and early planets during and after their accretion phases. The interdisciplinary research fields discussed contain different processes that produce chemical compositional changes after the solar nebula/chondrite stage. These, for instance, contain collisional erosion, post-nebula volatilization and the escape of noble gases and volatile elements that were dragged by hydrodynamically escaping hydrogen atoms originating from captured primordial atmospheres or magma ocean-related catastrophic outgassed steam atmospheres.