To those of you who think they know every little bit about canon, halo, and all it's characters please stop flaunting. You cannot completely know or understand halo canon. Namely in this the orbital MAC. Now scientifically we argue and debate back and forth over it. But think, our only knowledge about it comes from books and games. Now in the books whenever a MAC's power is addressed it is reffered to as, "A normal MAC blast could..." the thing is MAC technology has been already demonstrated in many ways, Ship board MAC's, MAC stations, The guass hog. Who says it cannot be fitted to a bombardment variant? Stating that something unaddressed or unmentioned in halo is non-canon is actually biased information and is actually fanon.
Don't try to argue science here, as it IS after all a fictional universe. On that is not fully detailed or fleshed out. You can't be positive in saying that a bombardment variant of a MAC is impossible, what are your sources? Never addressed in the books. And MC never had air support from a ship as large as the SoF. It's as plausable as anything else like it, combat rifles. And before other members start flooding me with, "Well if they went by that logic they could add werewolves in!" don't say anything as irrelevant as that. It's still a halo game. I'm just saying that the orbital MAC strike could easily (And probably will) become 'Canon'.
If all else fails; Duck. As a defensive stratagem it's very unreliable, but incredibly reassuring for a moment or two.