O Lucifer, son of the morning
The Versions in general agree in this translation, and render heilel as signifying Lucifer, the morning star, whether Jupiter or Venus; as these are both bringers of the morning light, or morning stars,annually in their turn.
Jupiter or Venus does not describe Lucifer. That would be more of a pagan description in respect to those who seek after gods .
Lucifer the counterfit light is a representation of the false gospel ,(no bright light). Christ who is described as the bright and morning star showing he is the bright Light reflected as a work of the father and Son working together in perfect submission and harmony , Like the Sun and the moon working as one.
The Son of the morning has no bright light( the difference )
Revelation 22:16 I Jesus have sent mine angel to testify unto you these things in the churches. I am the root and the offspring of David, and the bright and morning star.
I think he fell when Christ said it is finished, the same time those who were waiting in their grave rose up and entered the first resurrection..
To fall is not to be led by the Holy Spirit as sons of God .Previous Satan was allowed to mingle with the angels that did not fall from their first place of habitation. The veil is rent there will be no more minling with the angels that did not leave thier first place of habitation . He has been judged and never will be among them forever more
Job 1:6 Now there was a day when the sons of God came to present themselves before the LORD, and Satan came also among them.