![Van Krevelen diagrams of unaltered (left) and hydrolyzed (middle: soluble; right: insoluble) haze analogs for two water-rich exoplanets (top: 300 K; bottom: 400 K). Regions in H/C vs. O/C space are commonly attributed to broad classes of compounds, though these assignments can be less reliable for N-rich samples.-- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/11/Hydrolyzed-1.png?fit=1200%2C684&ssl=1)
[astro-ph.EP] Although photochemical hazes complicate the spectroscopic analysis of sub-Neptunes, the very presence of hazes can teach us about the habitability of these planets.
Aside from affecting a planet’s atmospheric and surface dynamics, hazes offer a source of organics potentially including prebiotic molecules like amino acids, nucleobases, and sugars. These organics are particularly compelling for temperate, water-rich planets where hazes may react with liquid water in condensate clouds or surface reservoirs.
Hydrolysis reactions drive molecular reorganization and oxygenation, increasing the chemical complexity of the prebiotic inventory. This water-based evolution of hazes in their environment is largely unexplored and will have consequences for their chemical and optical behavior.
In this work, we examine the chemical evolution of temperate water-rich exoplanet haze analogs in liquid water. High-resolution mass spectrometry finds thousands of CHNO molecules with bonding behaviors and chemical complexities distinct from the unaltered haze analogs.
The oxygen weight percent increases significantly in the soluble fraction and moderately in the insoluble fraction after hydrolysis, with different carbon bonding structures demonstrating the redistribution of functional groups. The hydrolyzed samples exhibit a broader distribution in H/C and O/C ratios, and the molecular formulas suggest complex carbohydrate chemistry that challenges current theories of prebiotic organic delivery.
Cara Pesciotta, Sarah M. Hörst, Michael J. Radke, Sarah E. Moran, B.P. Blakley, Chao He, Véronique Vuitton, Laurène Flandinet, Kathy Dubuc
Comments: 25 pages, 7 figures, accepted in PSJ
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2611.14666 [astro-ph.EP] (or arXiv:2611.14666v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2611.14666
Focus to learn more
Related DOI:
https://doi.org/10.3847/PSJ/aebf8b
Focus to learn more
Submission history
From: Cara Pesciotta
[v1] Tue, 10 Nov 2026 19:21:51 UTC (4,717 KB)
https://arxiv.org/abs/2611.14666
Astrobiology, Astrochemistry,
