There's a PDF for the LPSC2011 including side face pictures of track 40 in its "picokeystone" http://www.lpi.usra.edu/meetings/lpsc2011/pdf/2083.pdf - where it still looks like a hedgehog as it looks like from above

The PDF says it has a consistent morphology with a very high speed capture.
When it was a high speed capture, I can't understand the formation of his shape in the aerogel by such a high entry speed, i.e. what forces/circumstances can produce such a short cave form/track where the breadth of the entry hole is nearly as wide as the track?
Shows the entry hole the diameter of the origin particle or got it additionally widened by the process when the penetrating particle reacted with the aerogel? Was it more that the particle had a low density and got vaporized before it could generate a longer track like these from the comet particles?
Great that we possibly found at last a track that resembles the original calibration tracks!