Comet Hartley 2
Comet Hartley 2 The Deep Impact flyby spacecraft performed several extended missions after observing the Deep Impact impactor hitting comet Tempel 1 in 2005. In November 2011, it encountered comet 103P/Hartley 2. Hartley 2 was unusually active for a comet, its jets easily visible to Deep Impact's cameras without substantial processing. NASA / JPL / UMD / processed by Emily Lakdawalla

This image is from the High Resolution Imager, which had a problem with blurring. The Deep Impact team has released a version of the data set consisting of deconvolved images. This photo consists of one of those deconvolved images, overlaid with a transparent, blurred version of the same image, which brings out the jets more than in the unprocessed image.