Does it Ever Actually Turn Blue? Yes, but only in extremely rare atmospheric conditions. Large volcanic
eruptions (like Krakatoa in 1883 or Mount Pinatubo in 1991) or massive
forest fires can send ash and smoke particles of a very specific size
into the air. These particles scatter red light and allow blue light to pass through, giving the moon a blue-green tint. The
saying "once in a blue moon" means something happens very infrequently,
which perfectly describes how seldom the moon physically appears blue
or how rare an extra lunar cycle is. Dearest Karen, Have A Good Night Under The Blue Moon Light Pleasant Dreams Darlin' Always Loves And Hugs, XXOO ~WW~ {Sue}