[X] My Assistant

[cIclops]

An overlooked mission yet one that will be the focus of media attention in 155 days from now on July 4 2005, so there's time left to post a message before impact

cIc

[edstrick]

Pia02130 is a cleaned up but not deconvolved hirez camera image of the impact. The enhanced version clearly shows the defocused blur pattern of the high contrast sun-facing wall of the sharp depression at the terminator. The picture is badly out of focus, but at least this file does not have JPG artifacts introduced before it was turned into the TIF I downloaded.

The images is labled "Moment of Impact". The caption says, in part:

"When NASA's Deep Impact probe collided with Tempel 1, a bright, small flash was created, which rapidly expanded above the surface of the comet. This flash lasted for more than a second. Its overall brightness is close to that predicted by several models. After the initial flash, there was a pause before a bright plume quickly extended above the comet surface. The debris from the impact eventually cast a long shadow across the surface, indicating a narrow plume of ejected material, rather than a wide cone."

In the enhancement, the bright part of the flash is *NOT* saturated in the press release image, and has a very well defined sharp edge, beyond which there is diffuse glow which progressively gets fainter beyond the edge. I cannot tell if the edge is real, or an artifact of the imaging system or data processing, but if it's real, it's clearly an important feature of the expanding plasma and vapor cloud.

Low contrast mottled features are visible within the edge of the bright spot, in particular, there is a dark smudge at the bottom of the ejecta plume's shadow, apparently shadow visible through the bright "blob". The ejecta plume is not itself at all clearly visible or recognizable. Of particular interest, not otherwise noted yet that I've seen.. the shadow is *DOUBLE*.. with a darker portion on the right, and parallel to it a fainter portion on the left. This *might* suggest an irregular, maybe keyhole shaped hole punched in the surface layer of the comet with the high angle early ejecta emerging in a double plume.

I've tried enhancing later post-impact images. In the versions on the planetary photojournal, the brighter portions of the eject plume are saturated and contain no detail. Elswhere, there are strong vertical stripe and some horizontal stripe artifacts that have not been cleaned up from the totally raw data before the images were deconvolved, and they really degrade the enhancement. Image Pia02123 is the best of the 4 (2 of the 4 are the same data). The ejecta streamers are not perfectly radial to one point, but they do converge on a not-saturated part of the image just above a main saturated area and to the left of a smaller saturated bright spot. Texture is faintly visible in this area behind the strong vertical and several horizontal stripes from the camera artifacts, but no feature I'm inclined to interpret as a crater is evident above the noise and artifact level.

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