According to the mission timeline, the Deep Impact high-resolution observations of Hartley 2 are beginning in just a few minutes, at 20:50 according to the clock on the spacecraft.* All data are being stored onboard for relay to Earth over a period that'll span days after the flyby. Despite the fact that the flyby is only 17 hours away, Deep Impact can still not see the ball of ice and dirt that is at the center of all this cometary activity. In fact, it won't resolve details on the surface of the comet's nucleus until about an hour before its closest approach! In the meantime, though, the comet is making a fantastic show for the spacecraft to watch. Here's a quick animation made of four images from the Deep Impact website, the most recent of which is from Monday.
I'm planning on being at the Jet Propulsion Laboratory incredibly early in my morning tomorrow, showing up around 6:00 a.m. my time (13:00 UTC). I'll be Tweeting events as they happen, and blogging as quickly as I can after the fact.
* (Apologies to those of you on Twitter for my one-hour premature Tweet on this event. I copied a number from the Deep Impact website that was off by one hour.)