Comet Tempel Impact - July 3rd.  NASA crashes a probe, about the size of a coffee table, into comet Tempel 1 at 23000 mph.  The impact happened around 10:52PM PDT.  Notice the immediate change in brightness on the plot below.  For more information about the project, go to the link below.

Comet Tempel - 15 exposures at 300 seconds each.