Once In A Blue Moon


Have you ever heard of the expression, ‘Once In A Blue Moon’? Would you be surprised to learn that the Moon has actually been sighted many times as a physical Blue Moon, contrary to what the metaphorical and literal meanings of ‘Once In A Blue’ actually are.

The Moon is Earths only natural satellite, and the fifth largest satellite in our Solar System. It is also the only celestial body on which humans have landed, and we continue to be mesmerised by its beauty and fascinated by its charm. We look up into the night sky to dream and wish, and watch as it transforms from a new tiny sliver of light to a full bodied globe.

Phases of the Moon

There are four main phases of the Moon, plus a fifth not commonly known.

New Moon: A sliver of light is visible with the curves facing to the left
Waxing Moon: The crescent increases in size
Full Moon: The full Moon is visible in the shape of a circle
Waning Moon: The full Moon starts to diminish in size
Dark Moon: A brief period of time when the Moon cannot be seen at all, and lasts about three days before the crescent of the New Moon appears

Once In A Blue Moon

The complete sequence of the Moon phases, from new to full, takes a little over 29 days. There are 12 full Moons in some years, and 13 in others. Approximately once every two and a half years, 2 full Moons will fall within a single calendar month. The second in that same month, is known as a Blue Moon. ‘Once in a Blue Moon’ is a metaphor for ‘not very often’, but literally means ‘once every two and a half years’.

Although the term, ‘Once in a Blue Moon’, does not relate to colour, there have been reports of sightings where the Moon was in fact ‘blue’.

Blue Moon Sightings

In 1883, numerous sighting were recorded of Blue Moons, after an Indonesian volcano, named Krakatora exploded. Such was the force of the volcano that the ash spread through the atmosphere and remained present for years later. There were sightings of not only blue Moons, but lavender Suns and vivid red sunsets.

Other less potent volcanos have turned the moon blue also. In 1983, after the eruption of the El Chichon volcano in Mexico there were reports of Blue Moons, and also after the 1980 Mount St. Helens volcano and the 1991 Mount Pinatubo volcano.

According to NASA Science, the key to a blue moon is having in the air lots of particles slightly wider than the wavelength of red light and no other sizes present. This is rare, but volcanoes sometimes spit out such clouds, as do forest fires. Forest fires have also been attributed with Blue Moon sightings.

© Copyright Jan Reid-Lennox. All Rights Reserved.