Forum:When did (modern) humanity first encounter Forerunner tech?

I'm not very well-versed in Halo canon that takes place in the earlier years of the UNSC, so I'm seeking some guidance. When exactly did humanity first encounter Forerunner technology? Since they achieved slipspace travel and colonized many worlds, they were bound to find Forerunner ruins early on. Worlds like Harvest and Reach had Forerunner technology, although hidden from plain sight. But Arcadia had Forerunner ruins in plain sight with human cities built in their vicinity. This would all be fine and dandy, except for a few instances. In Halo: Reach, when unveiling the Forerunner artifact below the ice shelf, Halsey says "before you is an alien artifact neither human nor Covenant in origin", as if Noble team was oblivious to the concept of the Forerunners. And in Halo: CE, the halo is generally regarded as of unknown origin until Cortana says "...the ring...it's Forerunner...", however, not everything in CE fits seamlessly with current canon.-- Fluffy Emo Penguin ( ice quack! ) 23:08, 18 December 2012 (EST)