- last post: 01.01.0001 12:00 AM PDT
I agree with the origional post, although i don't have the books with me to back me up here, i'm sure that they find the location from those wierd forerunner artifacts which they scan for the co-ordinates.
I suppose another possibility is that when they origionally found us, they spread out and surrounded us, then closed in from all sides, slowly moving forward and glassing colonies.
I'm sure they have enough ships for that :)