After posting about how we landed a spacecraft on the asteroid Eros, I realized that I had actually been thinking about another craft intercepting an object in space...a comet, in fact. This was the Deep Impact mission, designed to discover how comets are formed and what they are made of.
So when I said that the Eros landing was one of the most amazing things this species has done, I was not quite accurate...this tops it:
The video shows an external view of a probe crashing into the comet, then the view from the probe itself as it closed in and impacted, and finally the comet moving off into the sunset...
While this mission wasn't apparently designed to test how we might deflect such an object from colliding with Earth, it does prove that, with sufficient notice, we could get a payload to even as elusive an object as a comet and nudge it or nuke it.
We live in incredible times.