A rock nobody saw coming

A twenty-metre rock came in over the Urals at nineteen kilometres a second, exploded with the energy of about half a megatonne, and injured 1,500 people, almost all of them by breaking windows.

It arrived from the direction of the Sun, which is precisely the blind spot no telescope can cover from the ground. Most of the injuries came from people going to their windows to look at the flash and being there when the shockwave arrived a couple of minutes later.