Your mother should have swallowed!
I'm very interested in this theory, as I do believe the next game Bungie makes will iclude the Chief, and somehow tie in the Marathon story, as the Halo games (set earlier than Marathon) were supposedly a prequel to the Marathon series.
Now what gets me, is exactly how the portal could send someone to another galaxy/deminsion, or universe.
Here's another thing, think about Gravatational pull. The planet we see isn't all that far... and if gravatational pull has anything to do with it, I think they will land there.
Good theory tho, OP... and yes, Tgamer514 is full of crap.
If a game called "Hologram"comes out on june 17th, i'll give you a million dollars.