In the last few days, Opportunity's passed by several craters, and the rover drivers took advantage of the chance encounters for what they call "drive-by shooting" (a phrase I can't say I'm particularly fond of, but they didn't ask me).
On Thursday, November 4, at 13:50 UTC, Deep Impact flew within 700 kilometers of comet Hartley 2. Hartley 2 is the smallest and most active of the five comets that have been directly by a spacecraft, and the first to be visited within the lifetime of its discoverer.
Several astronomers pointed their telescope at Eris to watch it pass in front of a background star. Occultations permit precise measurement of the diameters of distant, faint objects, and it turned out that Eris was much smaller than previously thought, so much so that its diameter may turn out to be the same as, or even smaller than, Pluto's.
I had to catch up with tasks left undone at home today and didn't have time to write up my notes from the Hartley 2 press briefing, for which I apologize. I'll leave you for the weekend with three cool Hartley 2 pictures.
It was a very happy set of scientists, engineers, managers, and administrators who filled the Jet Propulsion Laboratory's Von Karman auditorium this afternoon to do the postgame show on Deep Impact's flyby of Hartley 2.