![Retrieved temperature, mixing ratios, and haze parameters from all three retrieval set ups. Left: Retrieved volume mixing ratios for all three retrieval cases shown at the approximate depth of the haze layer. Right: Haze opacity in dashed lines and temperature in solid lines as a function of pressure and altitude. Where available we show the Teanby et al. (2006) mixing ratios and temperature profile. Despite varying assumptions and haze schemes, all retrievals indicate a haze layer in approximately the same pressure location. Note that the POSEIDON haze location is inferred from the pressure contribution functions and is shown as a shaded region. - [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/07/Piercing-through.png?fit=1200%2C668&ssl=1)
[astro-ph.EP] As we enter a new era of using JWST to characterize exoplanet atmospheres, a top priority is defining observational needs and parameters in the search for life on an exoplanet.
Although some studies have begun to consider Titan-like exoplanet atmospheres, more work is needed to prepare for the potential discovery and characterization of Titan analogues with JWST and future missions.
We explore the effectiveness of exoplanet atmospheric retrieval methodologies on the Cassini/VIMS-IR spectrum of Titan assuming agnostic haze properties and tholin hazes, as well as a self-consistent photochemical model. We compare our retrieved chemical abundances and haze profiles against fiducial values and Cassini/ISS-NAC UV observations and the forward modeled truths.
We generalize these findings to a Titan-like exoplanet in the TRAPPIST-1 system and find that JWST-like observations have limited potential to identify features beyond methane in a Titan-like atmosphere, but may be able to identify the presence of the haze to a few hundred kilometers.
The diagnostic features which would differentiate between different haze model (scattering) properties are shortward of 1micron and further demonstrate the important role of nUV — optical observatories in constraining the properties of exoplanet atmospheres.
We also find that agnostic priors for the bulk atmosphere can lead to a degeneracy in which a spectrally active gas (CH4) is erroneously favored as the dominant atmospheric constituent over a spectrally inactive molecule (N_2).
L. C. Mayorga, Jacob Lustig-Yaeger, Andrew P. Lincowski, Kathleen E. Mandt, Ryan C. Felton, Adrienn Luspay-Kuti, Kristin S. Sotzen, Cameron A. Gutsgell
Comments: 15 pages, 12 figure, accepted to AAS Journals
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2607.13255 [astro-ph.EP] (or arXiv:2607.13255v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2607.13255
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Journal reference: AJ 172 87 (2026)
Related DOI:
https://doi.org/10.3847/1538-3881/ae7712
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Submission history
From: Laura Mayorga
[v1] Tue, 14 Jul 2026 20:39:20 UTC (4,507 KB)
https://arxiv.org/abs/2607.13255
Astrobiology, Exoplanet,
