Astroblog: Seeing the Lunar X, Wednesday, February 5, 2025

Monday, February 03, 2025

Seeing the Lunar X, Wednesday, February 5, 2025


The Lunar X and V (indicated) as visible in telescopic views. Click to embiggen for a clearer view.	Western evening sky on Wednesday February 5 as seen from Adelaide at 21:43 ACDST	Western evening sky on Wednesday February 5 as seen from Brisbane at 20:19 AEST

The Lunar X (also known as the Werner X) and the Lunar V will be visible this Wednesday as the moon reaches Firt Quarter. 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 Lunar craters Blanchinus, La Caille and Purbach 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 Australian observers

Lunar X occurs on Wednesday February 5, 08:13 UT, 21:13 AEDST, 20:13 AEST, 20:43 ACDST, 19:43 ACST, 16:13 AWST). This is later than official first Quarter which occurs at 18:32 ACDST.

This is a telescope (and maybe good binoculars) only event. For the west coast the start of the Lunar X occurs when the sun is up, but the X is still visible 3 hours later in the deep twilight, with the Moon being 34° above the horizon, central states see it at 22° above the horizon, and for the east coast at 20° above the horizon.

Upcoming Lunar X' s are shown below:

Dates and time Lunar X and V are visible. Typically visible from about 4hours from the starting time, times in colour are daylight saving times.

Date	UT	AEST	ACST	AWST
Feb 5	08:13	21:13	20:43	16:13
Apr 5	12:43	22:43	22:17	20:43
June 3	13:18	23:18	22:30	21:18
Aug 1	10:57	20:57	20:17	18:57
Sep 29	08:46	18:46	18:16	16:46
Nov 27	10:43	21:43	21:15	18:43