This feature is actually the overlapping convergence of the rims of Blanchinus, La Caille and Purbach craters and there's only a small window in time where in Lunar X is visible. It's visible about six hours before 1st Quarter phase (Depending on the lunar libration), and for about an hour, the silver-white X will appear to float just beyond the lunar terminator as in this photo. So I'm really glad I got the chance to get this X on photo and to see it.
|Nikon D500, Nikon AF-S 600 mm f/4 with 1.7X converter|
Exposure: 0.4 sec. ISO 100 at f/8.0
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