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Global Mapping of HCl on Mars by IRTF/iSHELL

Aoki, S.; Vandaele, A. C.; Daerden, F. +6 more

Hydrogen chloride (HCl)—a key marker of the chlorine cycle on Mars—has been recently discovered in the Martian atmosphere by the ExoMars/TGO mission. In-orbit data indicate that this molecule appears in the atmosphere only in a limited time period and specifically in the southern summer season. A snapshot global mapping of HCl is indispensable to …

Accretion of Meteoric Organic Matter at the Surface of Mars and Potential Production of Methane by Ultraviolet Radiation

Janches, Diego; Villanueva, Gerónimo L.; Carrillo-Sánchez, Juan Diego +1 more

In this study, a comprehensive model of the meteoric organic cycle on Mars for the current geological period is developed, which characterizes the ablation of exogenous organic matter in the upper atmosphere, the accretion of intact carbon at the surface, and the potential production of methane by UV photolysis from the surface reservoir. The mode…

Strong Depletion of ¹³C in CO Induced by Photolysis of CO₂ in the Martian Atmosphere, Calculated by a Photochemical Model

Aoki, Shohei; Yoshida, Nao; Terada, Naoki +7 more

The isotopic signature of atmospheric carbon offers a unique tracer for the history of the Martian atmosphere and the origin of organic matter on Mars. The photolysis of CO₂ is known to induce strong isotopic fractionation of the carbon between CO₂ and CO. However, its effects on the carbon isotopic compositions in the Martia…

Depletion of ¹³C in CO in the Atmosphere of Mars Suggested by ExoMars-TGO/NOMAD Observations

Aoki, S.; Vandaele, A. C.; Daerden, F. +19 more

The atmosphere of Mars is mainly composed by carbon dioxide (CO₂). It has been predicted that photodissociation of CO₂ depletes ¹³C in carbon monoxide (CO). We present the carbon ¹³C/¹²C isotopic ratio in CO at 30-50 km altitude from the analysis of the solar occultation measurements taken by …