@65dBnoise Note that fluvial features needn't be those of water, anything naturally transitioning into a liquid phase or undergoing periodic, e.g. diurnal phase transitions will do. In case of Mars, with its extremely low surface temperatures and a very tenuous atmosphere, that could also be carbon dioxide undergoing regular deposition into dry ice, sliding down steeper slopes in its solid state and then sublimating back into its gaseous phase, one such cycle between the other sides of cabon dioxide's triple point every Sol. I'm not saying that's the case here, just that it's a possibility (that glacial features can look very similar to fluvial ones) that would need to be considered before drawing conclusions.