In the Book of Enoch the Watchers are a class of angels who descend to earth, take human wives, father the giants and teach humanity metallurgy, cosmetics, astrology and the cutting of roots, for which they are bound under the earth until judgement. The Book of Jubilees carries the same material, and Genesis 6:1 to 4 preserves a compressed version in which the sons of God take the daughters of men and the Nefilim are on the earth in those days. The tradition matters to the modern genre because it supplies a scriptural account of nonhuman teachers who transferred technology and were punished for it, which maps onto the ancient astronaut reading with very little adjustment. Amar Annus has argued that the Enochic Watchers descend from the Mesopotamian apkallu, and that line of descent is the route by which the ancient astronaut literature identifies the Watchers with the Anunnaki. Heather Lynn adopts the identification directly and ends her book on it. What the texts support is a shared literary genealogy between Jewish apocalyptic and Mesopotamian sage tradition. What they do not supply is any independent description of the beings outside those texts.
Connections
Apkallu · Anunnaki · Nefilim · Ancient Astronaut Hypothesis · Enuma Elish · Book of Enoch