资源环境科技发展态势分析平台

Following the recent detection of HCl in the atmosphere of Mars by ExoMars/Trace Gas Orbiter, we present here the first measurement of the ³⁷Cl/³⁵Cl isotopic ratio in the Martian atmosphere using a set of NOMAD observations. We determine an isotopic anomaly of ‐6 ±78‰ compared to Earth standard, consistent with the ‐51‰ to ‐1‰ measured on Mars’ surface by Curiosity. The measured isotopic ratio is also consistent with surface measurements, and suggests that Cl reservoirs may have undergone limited processing since formation in the Solar Nebula. The examination of possible sources and sinks of HCl shows only limited pathways to short‐term efficient Cl fractionation and many plausible reservoirs of “light” Cl.