A True Blue Moon

Sometimes we don't know what we think we know. Case in point, a blue moon. We tend to think that when a calendar month has two full moons, the second one is a blue moon. 

First problem with that colloquial reasoning is that mother nature doesn't operate on a twelve month cycle, neatly broken into 28, 29, 30 or 31 day months. Which is why seasonal changes happen 'around' the twenty-first day of December, June, March and September - the winter and summer solstice and the spring and autumn equinox.

Now back to the blue moon. Historically, a blue moon happens when there are four full moons in a season. And . . . it's not the fourth moon that is the blue one but the third. A true Blue Moon is the third of four in a seasonal quarter of the year. That apparently was the moon that felt 'out of place' rather than the fourth full moon, which would fall within a few days of the end of the season.

Here is when the full moons of this 'year' occur. Times given are PST & PDT:

28 December 2012, 02:21 (winter)
26 January 2013, 20:38 (winter)
25 February 2013, 12:26 (winter)
27 March 2013, 02:27 (spring)
25 April 2013, 12:57 (spring)
24 May 2013, 21:25 (spring)
23 June 2013, 05:32 (summer)
22 July 2013, 11:16 (summer)
20 August 2013, 18:44 (summer)
19 September 2013, 04:12 (summer)
18 October 2013, 04:37 (fall)
17 November 2013, 07:15 (fall)
16 December 2013, 01:28 (fall)

Tomorrow then is the true blue moon for this year. The third full moon of four that happen in the natural summer season. To celebrate here is Nanci Griffith singing Just Once in a Very Blue Moon.

Commentary on Monday, Portrayal on Friday