Still i have the following question:
Why is that words' order correct : the object X passed the earth at the same distance as will oject Y.
Why not "as object Y will"?
If the same is used for the past:
I came to the same place as you did(and not as did you)
the comet passed at the same place as comet y would(not would comet y)
The order is important in this case because you can compare similar items, i.e. action/activity with action/activity, noun with noun and so on.
In "D", the location is compared with location. "A" & "B" are incorrect idiomatically so don't even go there.
In "C" and "E", location is compared with Halley's comet.
This is what I figured but I may be wrong.