Here's two more items from Tuesday's flyby of comet Tempel 1 by the Stardust spacecraft to add to my previous roundup of Tempel 1 data. The first represents data from a dust counting instrument, portrayed as sound:
I asked co-investigator Don Brownlee several questions about the sounds audible in this clip, and he got back to me very quickly to explain that the few seconds of sound represent real-time data. There are three long and one short bursts of sound; he said that this burst character is real. That means Stardust didn't encounter a continuous snow of dust, but rather a clumpy distribution. I asked about the instrument used to gather the data, and Brownlee explained that "The data is from the PVDF [polyvinylidene fluoride] sensors on the Dust Flux Monitor Instrument. PVDF is a remarkable internally polarized plastic film that produces voltage pulses when penetrated or even dinged. The same film was also flown on the Soviet Halley missions Vega 1 and Vega 2." He provided a link to a dissertation by David James on PVDF dust detectors.
The other item is a terrific morph animation of the flyby produced by Daniel Macháček. He's colorized the animation using a brown color taken from Deep Impact's Tempel 1 images. The apparent shifting of color through the animation has to do with the automatic contrast enhancement applied to the images before they were posted to the Web; a movie made from actual spacecraft data wouldn't shift in color the same way.
Animation of Stardust's flyby of Tempel 1 Morphed animation of comet Tempel 1 (9P/Tempel) made from twelve images taken by the Stardust spacecraft (mission Stardust-NExT). Artificial color is based on images from Deep Impact mission. NASA / JPL / Cornell / Daniel Macháček
I've watched the video over and over and I think what surprises me most is how flat the surface of Tempel 1 appears to be in the region where Deep Impact hit it. In fact, the whole thing appears faceted rather than rounded. Also, I continue to wonder what is up with that thing that looks just like a cinder cone on the right-hand side of the limb in the approach phase of the images.