Lunar X and Lunar V

Every lunar cycle (29.5 days) the lighting on the Moon is just right that an X and V seem to appear underneath the terminator.  This only occurs for few short hours per cycle at certain locations on the Earth.  I was looking through the dates and times it was and is supposed to happen and noticed the date November 6, 2016 was good for Calgary.  I went through my photo database and noticed I was imaging the Moon that evening.  I had accidentally muddled my way into taking a picture of them.

Lunar X and Lunar V

An external link to a paper written on this topic by a fellow RASC member in Halifax is provided below.

http://wasociety.us/Lunar-X.pdf

The Lunar X and V are visual 'objects' created by what is known as the clair-obscur effect.  It is an interplay between light and shadow creating unique effects on a surface.  There are a number of these that you can see on the Moon during a given cycle.  A list is provided at an external link below.

http://the-moon.wikispaces.com/clair-obscur

You will need a good set of binoculars as a minimum to see this effect.  If you would like to see the Lunar X or V this year a list of the 5 remaining dates and times for Calgary in 2017 is provided below.

April 3, 16:21

June 1, 15:36

July 30, 14:33

September 27, 15:25

November 26, 18:46 MDT, 17:46 MST (will the savings time law be passed?)

Good luck hunting the sky!