Who knows what knowledge they may have possessed, but if that is meant to represent what is claimed, the Sumerians missed the single most impressive aspect of our solar system - Saturns rings. If they were represented, Id be impressed.
Here's one from a website on Sumerian Astrology that claims to show just such a knowledge.
29 posted on 02/23/2010 5:03:19 PM PST by Oatka
("A society of sheep must in time beget a government of wolves." –Bertrand de Jouvenel)