Why was Satan cast down to the earth

Why was Satan cast down to the earth.
That means the angels were created after the earth was made.
But why the earth?
Was it to try mankind?
“Lead us not into temptation
But deliver us from evil”
“Temptations must come.”
The devil was in the garden of Eden?
Or did he just possess the snake?
The devil is bound up with the creation of the earth.
Hell is inside the earth.
Is that Gods justice for his temptation and the downfall of many humans, to be perpetually bound in a hell enclosed by that very earth created for mankind whom he deceived and instigated his fall?
Why does the Bible say he was cast down to the earth instead of down to hell? Is hell considered as part of earth, being in its bowels? I say yes.

So what’s with the rest of the Universe apart from demonstrating the great power and beauty of God? Apart from Sun to give light by day and the moon to give light by night what is the significance of the other stars and planets which fill the night sky and shine in the darkness?
Do they represent other worlds similar to our own?
Does every star have its own earth?
Not according to the Bible.
Only the earth is inhabited.
The earth was created first before all else.
How much greater then must we marvel at the Universe.
A Universe we could have traversed had we not sinned.

Yet in all the Universe Satan is bound to the earth.
Heaven close by to the earth as angels come and go as they please and as pleases God.
Angels on earth always. Think if that.
Protectors against the demons and Satan and Lucifer and  Beelzebub
Earth is a busy place in the spirit realm
It has a great place in the end times as written in the Book of Revelations.
With streets of transparent gold.
In the new city of Jerusalem  which comes down out of heaven.
How marvellous.
Enchanting.
God in our midst in the New Holy City of Jerusalem. 1000 years or thereabouts into the future but we will live to see it because we will live 1000 years!
But a battle with the occupants of hell will again take place right before its arrival on earth.
Three times proves it, in this battle which will be the third and final time Satan and his hordes are cast out.
Try to think of eternal happiness and bliss.
That is our true meant to be state and nothing else. So never give up and into despair. 
God holds us in his plan for eternal happiness with Him!