The X is visible only for a few hours before the first quarter, slightly below the lunar terminator. Near to the X, the Lunar V is also visible, formed by Ukert crater and several other small craters.
- ↑ Rice, Tony, "X marks the moon on Thursday night".
- ↑ 2.0 2.1 Harrington, Philip S. (2010). Cosmic challenge : the ultimate observing list for amateurs. Cambridge: Cambridge University Press, 1999.
- ↑ Chapman, David M.F.. The Lunar X Files: a fleeting vision near the crater Werner. Willingboro Astronomical Society.