EDP Sciences

Vol. 608
In section 1. Letters

Detection of CS in Neptune’s atmosphere from ALMA observations

by R. Moreno, E. Lellouch, T. Cavalié, and A. Moullet A&A 608, L5


Evidence is mounting that Nepune, like Jupiter did with comet Shoemaker-Levy 9, suffered a large cometary impact that polluted its stratosphere in CO, CS and HCN. In the case of Neptune however, the comet was large (~4 km diameter) and the impact must have occurred ~1000 years ago. Moreno et al. use ALMA to detect for the first time the presence of CS in Neptune's stratosphere, and show that it is strongly depleted with respect to CO. Because of its different chemical properties, CS can stick to aerosols in the deeper stratosphere and be progressively lost. The timescale to diffuse to these regions and lead to the observed depletion is estimated to be ~1000 years.