Chemistry of Temperate Super-Earth and Mini-Neptune Atmospheric Hazes from Laboratory Experiments

Abstract

Very little experimental work has been done to explore the properties of photochemical hazes formed in atmospheres with very different compositions or temperatures than that of the outer solar system or of early Earth. With extrasolar planet discoveries now numbering thousands, this untapped phase space merits exploration. This study presents measured chemical properties of haze particles produced in laboratory analogues of exoplanet atmospheres. We used very high resolution mass spectrometry to measure the chemical components of solid particles produced in atmospheric chamber experiments. Many complex molecular species with general chemical formulas C${}_w$H${}_x$N${}_y$O${}_z$ were detected. We detect molecular formulas of prebiotic interest in the data, including those for the monosaccharide glyceraldehyde, a variety of amino acids and nucleotide bases, and several sugar derivatives. Additionally, the experimental exoplanetary haze analogues exhibit diverse solubility characteristics, which provide insight into the possibility of further chemical or physical alteration of photochemical hazes in super-Earth and mini-Neptune atmospheres. These exoplanet analogue particles can help us better understand chemical atmospheric processes and suggest a possible source of in situ atmospheric prebiotic chemistry on distant worlds.

22 pages, 8 figures, 9 tables, accepted for publication in the Planetary Science Journal

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Cited by in corpus (9)

• Habitability and Biosignatures of Hycean Worlds
• Atmospheric Regimes and Trends on Exoplanets and Brown Dwarfs
• Haze Evolution in Temperate Exoplanet Atmospheres Through Surface Energy Measurements
• Effects of UV stellar spectral uncertainty on the chemistry of terrestrial atmospheres
• An experimental and theoretical investigation of HCN production in the Hadean Earth atmosphere
• Triton Haze Analogues: the Role of Carbon Monoxide in Haze Formation
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• Grain Growth in Escaping Atmospheres: Implications for the Radius Inflation of Super-Puffs