2Hopkins Extreme Materials Institute (Johns Hopkins University, Latrobe 122, 3400 North Charles Street, Baltimore, Maryland 21218, USA - United States)
Météo-France (73 avenue de Paris
94165 Saint-Mande Cedex - France)
Abstract : Triton is the largest moon of the Neptune system and possesses a thin nitrogen atmosphere with trace amounts of carbon monoxide and methane, making it of similar composition to that of the dwarf planet Pluto. Like Pluto and Saturn's moon Titan, Triton has a haze layer thought to be composed of organics formed through photochemistry. Here, we perform atmospheric chamber experiments of 0.5% CO and 0.2% CH4 in N2 at 90 K and 1 mbar to generate Triton haze analogs. We then characterize the physical and chemical properties of these particles. We measure their production rate, their bulk composition with combustion analysis, their molecular composition with very high resolution mass spectrometry, and their transmission and reflectance from the optical to the near-infrared with Fourier Transform Infrared (FTIR) Spectroscopy. We compare these properties to existing measurements of Triton's tenuous atmosphere and surface, as well as contextualize these results in view of all the small, hazy, nitrogen-rich worlds of our solar system. We find that carbon monoxide present at greater mixing ratios than methane in the atmosphere can lead to significantly oxygen- and nitrogen- rich haze materials. These Triton haze analogs have clear observable signatures in their near-infrared spectra, which may help us differentiate the mechanisms behind haze formation processes across diverse solar system bodies.
https://hal-insu.archives-ouvertes.fr/insu-03559249 Contributor : Catherine CardonConnect in order to contact the contributor Submitted on : Sunday, February 6, 2022 - 1:31:59 PM Last modification on : Monday, April 11, 2022 - 3:56:32 PM Long-term archiving on: : Saturday, May 7, 2022 - 6:06:24 PM
Sarah Moran, Sarah Hörst, Chao He, Michael Radke, Joshua Sebree, et al.. Triton Haze Analogs: The Role of Carbon Monoxide in Haze Formation. Journal of Geophysical Research. Planets, Wiley-Blackwell, 2022, 127 (1), pp.e2021JE006984. ⟨10.1029/2021je006984⟩. ⟨insu-03559249⟩