In Gen 1, the earth is "without form . . . and there [is] darkness over the face of the waters. God creates a firmament to "separate the waters from the waters." The Hebrew word usually translated as "firmament" or "vault" is derived from the verb "raqquiah" (spelling probably wrong), which means to "hammer out," as a craftsman might hammer out a bowl from a piece of metal. It's clearly meant to be a solid dome, and the stars are "tiny lights" stuck on the inside of the dome. The non-canonical "First Book of Enoch" gives a detailed description of a dome with six doors at its base in the east, and six more in the west. The sun, it was believed, entered through the eastern doors, crossed the sky, and exited through the western doors, while the moon entered in the west and exited in the east. There were six doors to account for the observation of the sun's apparent movement southward in winter. Gen 1 describes the sun and the moon as "two great lights," but of course the moon is merely a reflector, with no light of its own. Enoch is mentioned in the "begats" later in Genesis, so someone borrowed his name for this book. Thus, "Enoch" is taken outside the dome by an angel, and observes that all is water (the "abyss" or underground sea which provides some of the water for the Great Flood and was considered the source of lakes, springs, seas, etc.) This cosmological view was shared among Middle Eastern cultures for millennia before the beginning of the Common Era (1 AD or, as scholars say now, CE). In Revelation, the stars are still believed to be small; some fall to earth and John, the narrator, says that he "walked past" a fallen star. Of course, any "falling star" would vaporize the earth long before actually striking it.
It's all nonsense, but it was the best guess the ancient Hebrews could make, given the state of their knowledge and their non-scientific view of the world. I have had students (Christians, of course) ask me how I could know "the universe wasn't really like that back then." I generally look for the answer to that one in the bottom of a glass of Scotch.