The most common of the non-pictorial
signs in use today to represent a target. A similar sign has been found on the brow of a
statue representing a priest king, living in what today is India. The
statue is dated back to around 3000 B.C.
This structure is quite common on rock faces in the Nordic countries and in other places. On a rock carving from Tanzania in Africa one can see the combination , where seems to be an ideogram for either the moon, or for the eclipsed sun. (See in Group 8 for more data.)
In 1576 the planetary system according to the theory of Copernicus could be represented by a similar structure made up of eight concentric circles.