Lunar data mining and “Alexander’s beaded rim”

October’s “Sky at Night” magazine has quite a few lunar images. The regular “Moonwatch” article is about the crater “Alexander” and its environs. Alexander is a difficult to identify eroded crater. In particular it talks about “Alexander’s beaded rim” about which it says “The peaks that define Alexander’s western rim appear like tiny stars arranged in a beautiful arc”. I have to confess that from the images in the magazine, this clair-obscur effect totally eluded me.

So, as I now have quite an extensive set of window-sill based images (of varying quality!) of the Moon in a variety of phases a bit of data mining was indicated. I found the following image which I cropped and labelled the features to be approximately the same as that in the magazine;

Then, after a bit of contrast stretching in GIMP, we get this:

NOW I can see an effect, although whether it is the one they were talking about, I don’t know! It is pretty though.


While looking at this image set, nearby there was also a pretty good manifestation of the Lunar “V”.

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