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Hey #agu11 people I have some questions for you #Experts. Feedback please? Whipple Lecture & mo' posters..

Whipple Lecture: Cometary nuclei

After a great salad at an uncrowded, close, inexpensive lunch spot that you would have as much luck getting the location from me as my favorite fishing hole (if I fished) I attended the Whipple Lecture given by Prof. Whipple’s last PhD student, Joseph Veverka. Prof. Veverka discussed the Deep Impact and Stardust measurements of comet Tempel 1, the first comet with sufficiently high resolution images to explore the geology of the body.

The observations are a neat story because Deep Impact first visited Tempel 1, impacted it, but no observations of the resulting crater were possible as the dust didn’t settle fast enough. So they were lucky enough that 5.5 yr later they could return to the same spot with the Stardust spacecraft. And by some amazing orbital tinkering they came back at the right time for closest approach over exactly the spot they wanted. That being said, the results were, well, modest. More like “Cursory Impact”.

Anyway, there modeling work suggests the surface is similar to “lightly packed mountain snow”. A surprising thing I learned in the talk was the unlike mountain snow there is virtually no frozen water on the surface of this dirty snowball (sounds like one of those drinks on the bar menu I never order).

Another interesting results: the surface is covered with craters but they are not impact craters. They appear to be caused by material from the interior bubbling up to the surface. Also present on the surface are regions of melt which have flowed to the valleys of the surface (this little guy has a 850 m elevation gain on a body with a radius of 3 km!).

So the hallmark of a good talk, it raised lots of questions in my mind.


Evening science meeting now so gtg. Enjoy your science.

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