The Lunar X is created by sunlight falling on the rim of the Blanchinus, La Caille and Purbach craters near the terminator. The X is visible only for an hour or so before first quarter. The Lunar V, formed by Ukert crater and several other small craters, is visible for a couple of hours.

Celestron f/6.3 102mm refractor on Alt/Az mount/Samsung S5 Neo cell phone camera and digiscoping adapter

Single frames tweaked with Microsoft Photo