:’D
Gene Shoemaker said that, an object a mile or so in diameter, delivers on impact more energy than if one were to take all the nukes on the planet, put them into one pile, and set them all off simultaneously. IOW, kind of a lot. :’)
This Apophis thing is only 0.27 kilometer diameter, the online conversion gizmo renders that as 885.8 feet. Pipsqueak. It would only be like, oh, something like one half of one per cent of that amount of energy. And of course, relative velocity plays an important role in the amount of energy, so I won’t worry too much either. ;’) Y’know, give or take having it land near here.