I don't know, but compared to the scale of the gigantic crater that's visible in the image, whatever it was was pretty much nothing in the grand scheme.
The impact that made that huge crater must have been an amazing light show...
I bet it did. The dinosaurs were probably impressed.
I've never thought of this before, but I imagine the ground could have glowed for minutes or hours, and been visible from Earth. That would have been quite something to see from a safe distance.