This was how Schiaparelli related Ptolemy's Earth to Mars. The Greek Sun god, Helios, rode a chariot across the sky, rising in the far east of the world and passing over it during the day. At sunset he descended into the far west, moving by boat under or behind the world, back to the east for the next sunrise. So on Mars he would move over the planet, passing places named for regions he saw during his terrestrial daytime journey. #Mars#Helios