How silly to think you could go back thousands of years and map the skies with today's technology! We haven't even identified all the objects in our solar system. (but we have solid information and knowlage of the main planets in the solar system!)
It is a good thing science has God for a motivator lol!
No, it's not silly, it's quite simple really, it's all in the mathematics, we "know" the math is right for the calculations on the orbits of the planets and when dealing with what the ancients saw you pretty much stop at Saturn, because that is the farthest planet that can be seen with the naked eye. And the placing of celestial objects is just as easy, the ancients knew pretty much the same sky we do(though they saw a richer and more detailed sky do to the fact they didn't have massive cities throwing light in the sky every where!) and they took very accurate and detailed observations, they haven't changed positions in the sky that much in the past 10000 years or more. SO, if you know where they are today, it's not hard to know where they would have been in the past. I have an astronomy program that goes all the way back to 5000 BC and Orion looks just like it does to us as it did to the Egyptians.
And yes, God is a great motivator of science(By using science to explain, let's say the ten plagues of Egypt during the exodus, we better understand how it could have happened and better proves that it actually DID happen and not to be taken as a fairy tale of imaginative writing, and that's not taking God out of it, who's to say that God can't manipulate the Earth and weather to do what was done.)...Just because we humans want to know the whys and hows doesn't mean that it's meant to disprove God(that's dark age thinking and dangerous!), I say it's all for a better understanding of how the universe works and doesn't take away from personally spirituality, or at least it shouldn't and it doesn't with me, in fact it helps confirm it. ( In other words if science can prove that something written in the Bible could actually have happened then why not let science be a tool for better understanding? ).