Let's turn back the clock a few dozen minutes.
Above, the fierce battle set ablaze the entire expanse of sky within visibility, the apocalyptic flames having already evaporated all the clouds, rendering the poisonous haze that had loomed over the East Plague Land for years a mere joke within this ferocious web of firepower. No virus could withstand the heat akin to the surface of a star. The immense power of the Mother Ship's Main Cannon even dyed the entire dome an unnatural shade of dark red; if the warriors on the ground from Azeroth had any advanced scientific knowledge, they would have been horrified to realize that this was an omen of the atmosphere igniting.
Of course, both sides of the battle had taken precautions, after all, a planet burned to ashes held no value to anyone.