Characterizing Exoplanetary Atmospheres: New Views on Exoplanet Composition and Chemistry

TL;DR

This review discusses recent advances and ongoing challenges in characterizing exoplanet atmospheres, highlighting the role of spectroscopy from JWST and ground-based telescopes in understanding planetary composition, physics, and formation.

Contribution

It synthesizes current knowledge and identifies key open questions in exoplanet atmospheric science, emphasizing new observational capabilities and their implications.

Findings

High-quality spectra from JWST enable atmospheric abundance measurements for gas giants.

JWST spectra are beginning to be used for sub-Neptune planets.

The study aims to determine the presence of long-lived atmospheres on terrestrial planets.

Abstract

I review the major open science questions in exoplanet atmospheres. These are mainly focused in the areas of understanding atmospheric physics, the atmosphere as a window into other realms of planetary physics, and the atmosphere is a window into understanding planet formation. For gas giant planets, high quality spectra have been delivered from JWST and from the ground, enabling the determination of atmospheric abundances. For the very common sub-Neptune planets, we are just beginning to obtain and interpret JWST spectra. For the terrestrial planets, which can be studied only around M stars, the field aims to determine if these planets even have long-lived atmospheres.