Assessing the Robustness of Exoplanet Atmospheric Detections in the Era of JWST

Amidst the excitement of groundbreaking discoveries, it becomes imperative to address the fundamental question: “what does it mean to detect something in an exoplanet atmosphere?” Recent results from the James Webb Space Telescope (JWST) have underscored the challenge of separating real atmospheric constituents from noise-induced and unknown astrophysical artifacts. By exploring different noise regimes, we statistically interrogated the frequency and characteristics of low-sigma, false-positive detections. Using the sub-Neptune exoplanet K2-18b as a case study, we assessed discrepancies between Hubble Space Telescope (HST) and JWST observations, with a specific focus on water and methane abundances. This research will aid in the establishment of a standardized approach for evaluating the reliability of reported detections, thus enhancing the reproducibility and integrity of exoplanet atmospheric studies, and providing direct applications to the field of astrobiology.