Chemical Complementarity between the Gas Phase of the Interstellar Medium and the Rocky Material of Our Planetary System

TL;DR

This study reveals a strong chemical complementarity between the gas phase of the interstellar medium and the rocky material of our Solar System, highlighting the inheritance of primordial dust and its role in planetary formation.

Contribution

It introduces an inheritance model explaining how interstellar dust contributes to the formation of primordial planetary material, linking interstellar and planetary chemistry.

Findings

Elements depleted in ISM gas are enriched in planetary rocks.

Primordial dust inherited from ISM forms the basis of planetary material.

Chemical composition varies with distance from the Sun, observed in different meteorites.

Abstract

We compare the elemental depletions in the gas phase of the interstellar medium (ISM) with the elemental depletions in the rocky material of our Solar System. Our analysis finds a high degree of chemical complementarity: elements depleted in the gas phase of the ISM are enriched in the rocky material of our Solar System, and vice versa. This chemical complementarity reveals the generic connections between interstellar dust and rocky planetary material. We use an inheritance model to explain the formation of primordial grains in the solar nebula. The primary dust grains inherited from the ISM, in combination with the secondary ones condensed from the solar nebula, constitute the primordial rocky material of our planetary system, from which terrestrial planets are formed through the effects of the progressive accretion and sublimation. The semi-major-axis-dependence of the chemical composition of rocky planetary material is also observed by comparing elemental depletions in the Earth, CI chondrites and other types of carbonaceous chondrites.