good news: you landed on an ancient powerful artifact left behind by some ancients.
bad news: you have to blow it up before it kills everyone trying to stop the flood from covering the Earth.
(btw, you KNOW that is where it has to end up going, if it has Earth in it, there is like 99% chance something bad is supposed to happen, and 2 things in halo this could be, halo, or the flood.)
btw, sorry if you have yet to even get that far in the story, anyone else who read this. also, did you beat it on the legendary skill level? (hardest one, I think it was legendary, that or heroic) I loved that scorpion tank, 100% total pawnage of about everything else in the whole game, even other players, if used right
*snipes another player in mid-air with scorpion cannon*