Therefore, in examining ancient Near East mythology, we should expect to see an understanding of outer space from the extensive knowledge the aliens supposedly gave the Sumerians and others. At the most basic level, this should mean that the ancients understood that space was a vast empty territory beyond the earth which could be reached by traveling high enough into the sky, with no barriers between the earth, the planets, the stars, and the galaxies beyond.
So what do the Sumerians say about the sky?
Well, no matter. Robert Temple’s sources were Babylonian rather than Sumerian (the priest Berossus), so perhaps the Babylonians are the place to look for this knowledge.
According to the Babylonian Enuma Elish, the sky is a solid barrier raised like a roof over the earth (4.137-138) in which there were gates (5.9-11) through which the sun passed.
Maybe the Egyptians can do better.
According to the Pyramid Texts, the sky was conceived as a solid mass that required support from gods who hold it up. Max Müller argued based on several texts that the Egyptians believed the sky to be a dome made of iron from which the stars were suspended on cables. They knew it was crafted from iron because meteorites that crashed to earth were made of iron and must therefore have been pieces of the dome.
Well, this isn’t going well. Let’s try the Greeks.
The two oldest extant Greek sources are Homer’s Iliad and Odyssey. According to the Iliad, the dome of heaven was a solid roof of bronze (Iliad 17.425), while the Odyssey claims that the heavens were instead made of iron (Odyssey 15.329). Other myths make evident that the sky was conceived as a solid dome, or else Atlas would have had nothing to hold. The stars, the Greeks thought, were fixed in the dome of the heaven (e.g. Aristotle, De caelo, 2.8, 3.1).
But certainly the Book of Enoch at least means that the Jews had special knowledge of the heavens.
In Genesis 1:6-8, God separated the water above from the water below by creating a vault within the waters, just as in the Babylonian and Sumerian creation stories. Since there was water above the sky, the sky, called the “firmament”—the Hebrew term meaning literally the “solid sky”—must be solid to hold back these waters from merging again with the waters below. St. Augustine elucidated this position, which Christians adopted. Crucially, Jewish apocryphal literature makes clear that the ancient Jews speculated whether the firmament were composed “of clay, or of brass, or of iron” (3 Baruch 3:7). Origen, the Christian father, writes in his first homily on Genesis: “Omne enim corpus firmum est sine dubio, et solidum”—that without doubt the firmament was both firm and solid. (For more on the Judeo-Christian firmament, see Paul H. Seely's article on "The Firmament and the Waters Above.")
Apparently Temple’s flying space frogs did a poor job educating the Sumerians or any other group. So where, exactly, do AATs think the ancients imagined their aliens coming from?