Every month a couple hours before the first quarter moon, there is a feature visible resembling the letter X. In reality, it’s light reflecting off of the rims of the Blanchinus, La Caille and Purbach craters. It’s visible in small telescopes, and with binoculars, but you’ll need a stable platform.
The following image is a stack of 41/400 video frames, shot with BackyardEOS, and stacked in RegiStax. Someday I might do a tutorial.