Monday, April 23, 2012

Steins: Closest Approach

Following up on my previous post with the best Narrow Angle Camera image of the asteroid Steins from ESA's Rosetta spacecraft, I have reprocessed the images taken by the Wide Angle Camera around closest approach.  While the apparent image size in the frames at closest approach isn't much bigger, the phase angle is higher, meaning that there are more shadows.   Higher contrast features are easier to positively identify even when they only take up a few pixels, since they are less likely to get lost in instrument noise.  What made this image harder to produce (despite only being able to decently align four frames) is that there is a serious change in viewing angle from image to image.  The images used are W20080905T183758428ID20F17, W20080905T183802520ID20F17, W20080905T183804306ID20F14 (used as a base to align the other frames), and W20080905T183805803ID20F15.   I am much more pleased with the result than the image in the previous post.   It seems to be reasonably sharp given the dataset available and large enough to be viewed comfortably.

The second version has been filtered to enhance the visibility of faint details.

Processed images Copyright Ted Stryk

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