Compositional Diversity of Rocky Exoplanets

TL;DR

This paper explores the compositional diversity of rocky exoplanets by analyzing stellar elemental abundances and mineralogies, highlighting the typical mineral compositions and the need for integrated geological and astronomical research.

Contribution

It provides a detailed assessment of mineralogical compositions of rocky exoplanets based on stellar data, emphasizing the importance of combining geological insights with astronomical observations.

Findings

Exoplanetary silicate mantles mainly contain olivine, orthopyroxene, and clinopyroxene.

Exotic mineralogies are likely absent in rocky exoplanets.

Understanding exoplanet geology requires integrating geological experiments with astronomical data.

Abstract

Star compositions are essential for examining densities and compositional ranges of rocky exoplanets, testing their similarity to Earth. Stellar elemental abundances and planetary orbital data show that of the ~5000 known minerals, exoplanetary silicate mantles will contain mostly olivine, orthopyroxene, and clinopyroxene, $\pm$ quartz, and magnesiuwustite at the extremes; wholly exotic mineralogies are likely absent. Understanding these exotic geological systems requires a better marriage of geological insights to astronomical data. The study of exoplanets is like a mirror, reflecting our incomplete understanding of Earth and neighboring planets; new geological/planetary experiments, informed by exoplanet studies, are needed for effectual progress.