Although the clear sky seems to us to be
shaped like a dome, rather than a flat circle, there is no direct evidence that
ancient Mesopotamians thought the visible heavens to be a dome. Akkadian kippatu are always flat, circular
objects such as geometric circles or hoops, rather than three dimensional
domes. Nonetheless, evidence for dome-shaped, or curved, heavens may be found
in the ziqpu-star text BM 38693+, the
blessing formula STT 340:12, and AO 6478, where the Path of Enlil is 364° long.
All three imply that the Path of Enlil, at least, is a curved band that
encircles the earth's surface (see p. 258). However, this does not prove that
the surface of heaven is curved, since stars need not have necessarily traveled
along the surface of the sky. 30 There is also no direct evidence for the shape
of the high unseen heavens, although it is likely that these levels too were thought
to be circles. A cryptic reference to the possible circular shape of the Heaven
of Anu may be found in a šu.fla where
the Heaven of Anu is identified with a nignakku 'censer' (Ebeling Handerhebung
14:16). Censers were flat, round objects. (Wayne Horowitz, Mesopotamian Cosmic Geography [Winona Lake, Ind.: Eisenbrauns,
1998], 264-65)