It seems that Greek astronomy could at least in its earliest times occasionally be mixed with mythology if not also religion.
Thus, from Michael Hoskin (1997) "The Cambridge Concise History of Astronomy" (p.19):--
"When we come to study the earliest Greek attempts to make sense of
the universe, we find that our sources are fragmentary in the extreme.
What little we have owes much to the custom of Aristotle (384-322 BC),
of citing his predecessors before demolishing them. It seems that
alongside the mythologies inherited from earlier times, there
gradually emerged a speculative interest in the natural world, which
led to efforts to make sense of nature - rather than to attempts to
answer quantitative questions, such as led to the columns of numbers
on the Babylonian tablets. But what we would recognize as a mature,
predictive science of astronomy was to develop only in the Hellenistic
era, when these two approaches, the Greek and the Babylonian, merged."
Thus, according to this historian, mythological elements in Greek astronomy had been present at so early a date that little of their thought has survived, but these elements were being replaced even as early as the 6th-c. BC by ideas of 'impersonal laws':--
"Anaximander (c.610-c.545 BC), also of Miletus, attempted to explain
the form of the heavenly bodies in the context of his vision of worlds
constantly coming into being from the Infinite, only to perish and be
reabsorbed into the Infinite. If we can rely on accounts written many
centuries later, he thought of the stars as wheel-like condensations
of air filled with fire, with openings through which flames were
discharged. The Sun was the highest (that is, most remote) of the
heavenly bodies, with the Moon next below it, then the 'fixed' stars
(those unchanging in their positional relations), and finally the
planets. The Earth he believed to be a cylinder, on one of whose end
surfaces lived mankind; it rested in the middle of the universe,
remaining where it was because it had the same distance from
everything. The limitations of this cosmology are evident, but a
fundamental shift had occurred: earlier mythologies had been replaced
by a nature in which an impersonal law was at work."