I answered my first map question in a separate post. Back to Herschel: his map has no coordinates but coordinates can be approximated. I projected the Herschel map into a cylindrical projection and then into two equator-centred azimuthal projections making the best match I could to modern coordinates. My intention was to take a variety of historical and recent maps in different projections and display them all in a common format for comparison. #maps#Mars#Herschel