Hazes and Habitability: The Interaction Between Atmospheric Haze and Liquid Surface Water

Observations and modeling of temperate exoplanets reveal hazy atmospheres, coming as no surprise due to the prevalence of photochemical hazes in our Solar System on bodies like Titan. In addition to affecting spectra, hazes influence chemical and physical processes in atmospheres and surfaces. The best-studied hazy world, Titan, forms haze through photolysis of its N₂ and CH₄ atmosphere, producing complex organic aerosols that supply material to the surface. These particles may interact with liquid surface water, made possible through cryovolcanism or impacts on the water ice shell, to create prebiotic molecules like amino acids and nucleotides. Laboratory studies suggest that a wide variety of exoplanet atmospheres also produce organic haze. On water-rich planets, it is likely that the particles that fall out of the atmosphere will react with liquid water. Here, we perform a series of hydrolysis experiments on laboratory simulated hazes in water-rich exoplanet and Titan-like atmospheres. Water-rich exoplanet haze analogs are formed through photolysis of gases at 1000x solar metallicity, and Titan haze analogs are formed through N₂-CH₄ photolysis. We obtain the optical constants and compositions of these hydrolyzed haze analogs, informing future observation analyses and uncovering biological relevance.