REMOTE SENSING OF ATMOSPHERIC ISOTOPIC RATIOS IS NOW MORE ACCESSIBLE THAN EVER AND IT HAS RECENTLY PERMITTED US TO INFER THAT MARS LOST AN OCEAN S WORTH OF WATER (VILLANUEVA ET AL. 2015) AND THAT COMETS MAY HAVE DELIVERED THE WATER TO OUR PLANET (HARTOGH ET AL. 2011; VILLANUEVA ET AL. 2009). AT LONGER WAVELENGTHS THE ALMA ARRAY IS REVOLUTIONIZING THE CHARACTERIZATION OF PLANETARY ATMOSPHERES BY PERMITTING HIGH-SPATIAL RESOLUTIONS AND UNPRECEDENTED SENSITIVITIES AS DEMONSTRATED BY THE SURPRISING MAPS OF HNC AND HC3N OBTAINED OF TITAN (CORDINER ET AL. 2014) AND THE VERTICAL PROFILES OF PLUTO S ATMOSPHERE (LELLOUCH ET AL. 2016).