Image: K2-18 b Mid-Infrared Transmission Spectrum

Description: An infrared transmission spectrum of the exoplanet K2-18 b taken by the JWST MIRI LRS instrument which was released in the 2025 study "New Constraints on DMS and DMDS in the Atmosphere of K2-18 b from JWST MIRI" (Madhusudhan et al. 2025). Quoting from that studyː "The data points with error bars (in brown) show the observed spectrum as described in Section 2.1. The horizontal error bars correspond to the spectral bin width. The dark blue curve denotes the median retrieved spectral fit, while the two lighter shaded regions denote the 1σ and 2σ intervals. The prominent features of DMS and DMDS are identified. Both molecules have overlapping spectral features between 6.8 and 8 μm, with broader features between ∼9 and 10 μm for DMS and ∼10–11 μm for DMDS" (page 4). K2-18b has been discussed as having the necessary conditions to harbour alien life, with the authors attaching importance to the chemicals dimethyl sulfide (DMS) and dimethyl disulfide (DMDS) which they claim are possible biosignatures. These interpretations have been disputed by other scientists (see K2-18 b Wikipedia article). The study was published by the Astrophysical Journal Letters hereː https://iopscience.iop.org/article/10.3847/2041-8213/adc1c8 It clearly states that "Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence.". This image has been scaled from the original and saved as a .png file.
Title: K2-18 b Mid-Infrared Transmission Spectrum
Credit: New Constraints on DMS and DMDS in the Atmosphere of K2-18 b from JWST MIRI https://iopscience.iop.org/article/10.3847/2041-8213/adc1c8
Author: Nikku Madhusudhan et al. 2025
Usage Terms: Creative Commons Attribution 4.0
License: CC BY 4.0
License Link: https://creativecommons.org/licenses/by/4.0
Attribution Required?: Yes