Atmospheric charged clusters are formed in a series of rapid chemical reactions after ionisation, leaving a central ion X or X clustered with n ligands (Y) . In solar system tropospheres and stratospheres there are two distinct cluster regimes: the terrestrial planets contain largely hydrated clusters (i.e. Y=HO), whereas the gas planets and their moons have organic or nitrogenated cluster species. These classifications are largely based on model predictions, since hardly any measurements ar...