Hakim, Kaustubh

Invited talk presented at Strange New Worlds Exoplanet Conference, IISER Pune, India on 2023-08-18

Abstract: This decade is witnessing a major shift from the characterization of gas giant exoplanets to their smaller counterparts. Planet occurrence studies focusing on size distribution of planets have revealed three major classes of exoplanets, gas giants, gas dwarfs (sub-Neptunes), rocky worlds (super-Earths and smaller planets). Unlike gas giants, super-Earths and sub-Neptunes are dominated by their rocky interiors. In the absence of direct measurements, following astronomical windows reveal rocky interiors. Mass-radius measurements inform about bulk planet composition, atmospheric characterization reveals atmospheric composition, and stellar elemental abundances give potential estimates on interior composition. While the observations of atmospheres of intermediate-sized and small exoplanets keep growing, the understanding of planetary interiors and interior-atmosphere interactions is more vital than ever. In this overview talk, I will focus on terrestrial-type exoplanet interiors and evolution from a perspective of chemical and physical diversity. The interior composition, mineralogy and structure are largely determined by the inventory of refractory elements. The interior evolution and atmospheric chemistry are further influenced by the inventory of volatile elements. I will discuss the role of exoplanet interiors on the composition of atmospheres including processes such as geochemical cycling, outgassing and atmospheric escape. Going forward, we will need to develop a thorough understanding of planetary mineralogy, material properties and processes that take place outside the physical and chemical realms of Earth and planetary bodies in the Solar System with the help of theoretical models and laboratory experiments.

Funding: FED-tWIN STELLA/FED-tWIN STELLA/FED-tWIN STELLA