Pluto, Titan, and Triton make up a unique class of solar system bodies, with icy surfaces and chemically reducing atmospheres rich in organic photochemistry and haze formation.
Hazes play important roles in these atmospheres, with physical and chemical processes highly dependent on particle sizes, but the haze size distribution in reducing atmospheres is currently poorly understood. Here we report observational evidence that Pluto’s haze particles are bimodally distributed, which successfully reproduces the full phase scattering observations from New Horizons.

Combined with previous simulations of Titan’s haze, this result suggests that haze particles in reducing atmospheres undergo rapid shape change near pressure levels ~0.5Pa and favors a photochemical rather than a dynamical origin for the formation of Titan’s detached haze. It also demonstrates that both oxidizing and reducing atmospheres can produce multi-modal hazes, and encourages reanalysis of observations of hazes on Titan and Triton.

Siteng Fan, Peter Gao, Xi Zhang, Danica J. Adams, Nicholas W. Kutsop, Carver J. Bierson, Chao Liu, Jiani Yang, Leslie A. Young, Andrew F. Cheng, Yuk L. Yung

Comments: Published in Nature Communications, 26 pages, 12 figures
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Journal reference: Nat Commun 13, 240 (2022)
DOI: 10.1038/s41467-021-27811-6
Cite as: arXiv:2201.04392 [astro-ph.EP] (or arXiv:2201.04392v1 [astro-ph.EP] for this version)
Submission history
From: Siteng Fan
[v1] Wed, 12 Jan 2022 10:05:52 UTC (2,355 KB)