Abstract EANA2026-80

For the past five years, particularly following the launch of the James Webb Space Telescope (JWST), the exoplanet community has focused heavily on terrestrial planets orbiting M dwarfs, owing to the observational advantages offered by their small host stars. The “low-hanging fruit” of atmospheric characterization have been short-period rocky planets receiving intense stellar irradiation, whose elevated dayside temperatures make them favorable targets for thermal emission and eclipse observations aimed at probing atmospheric heat redistribution. However, the majority of current results remain either ambiguous or consistent with airless rocky surfaces.

This raises an important question: are rocky planets around M dwarfs intrinsically unlikely to retain atmospheres, or are current conclusions driven by a strong observational bias toward the most highly irradiated systems? In this work, we examine whether atmospheric characterization through transit spectroscopy of more temperate, Earth-sized planets in the habitable zones of M dwarfs is not only technically feasible, but also a compelling alternative despite the limited number of suitable targets and the large investment of James Webb Space Telescope observing time required. Using simulations and observational constraints, we explore the detectability of atmospheric signatures in cooler terrestrial planets and discuss whether the next step for the field requires moving beyond the easiest targets toward the most informative ones.