Seeing the Lunar X, Friday, November 8, 2024

The Lunar X and V (indicated) as visible in telescopic views. Click to embiggen for a clrear view.	Western evening sky on Friday, November 8 as seen from Adelaide at 23:19 ACDST	Western evening sky on Friday, November 8 as seen from Brisbane at 22:49 ACDST

Pareidolia (the tendency to perceive a specific, often meaningful, image in a random or ambiguous visual pattern) abounds on the moon, the “Man in the Moon” and “the lunar Rabbit” are the most famous examples we can see every full moon, caused by the placement of the dark lava planes and the brighter uplands. 

Placement of craters and shadows can also case us to see fanciful shapes. 

One of the most famous and elusive is the Lunar X (also known as the Werner X) and the Lunar V. The Lunar X is a chiaroscuro effect in which strong contrasts of light and shadow create the appearance of a letter 'X' on the rim of the Blanchinus, La Caille and Purbach craters of the Moon and a letter V from the rim of the crater Ukert, along with several smaller craters. 

The X and V are seen at first quarter, visible on the lunar surface for about 4 hours. However, the Moon is not always above the horizon from a given vantage point when this happens. This month is good for Australia. 

Lunar X occurs on Friday November 8, 1249 UT 1249 UT (23:49 AEDST, 22:49 AEST, 23:19 ACDST, 22:19 ACST, 20:49 AWST). This is earlier than official first Quarter which occurs at 16:000 AEST.

This is a telescope (and maybe good binoculars) only event.The west coast is favoured with the Moon being 48° above the horizon, central states see it at a decent 29° above the horizon, and for the east coast a lower but still decent 24° above the horizon.

The next Lunar X is  Dec 08 0236 UT (14:36 AEDST, 14:06 AEDST, the Moon is on the horizon in WA), which is a daytime event in Australia, but still may be a decent telescope view.