There does not appear to be any instruments that are completely definitive, even from 'near' remote sensing, such as on a simple lander. It is not only necessary to determine that there might be water ice, but the quantities and composition.  -   Larry Taylor     Quotes
There does not appear to be any instruments that are completely definitive, even from 'near' remote sensing, such as on a simple lander. It is not only necessary to determine that there might be water ice, but the quantities and composition. Larry Taylor