|
How
often does it occur?
Blue moons occur once after
every two years and nine months. This is the time it takes for the lunar
cycle to shift and a full moon to occur at the beginning of the month.
And once in nineteen years,
a single year will see two blue moons. The year 1999 was one such. The
months January and March had two full moons each. February, however, did not
witness a full moon at all. Two blue moons within two months of each other
was a rare treat for moon watchers. This phenomenon last occurred in 1915.
The last time that February missed a full moon was in 1961 and calculations
point out that it will miss one again in the year 2018.
The
reasons for the use of the term ‘blue moon’
Various reasons have been
cited for the use of this term. One plausible explanation is that when
color printing was first used, a popular Almanac used red color to point
out the first full moon and blue color to point out the second full moon in
a month.
The phrase ‘blue moon’
has been around for almost 400 years. This phrase has been used by writers
to point out obvious absurdities. ‘Blue moon’ has been used in this
context in literature dating back to 1528. Later uses in literature have
been to denote not absurdities but the impossibility of the happening of an
event. The term ‘blue moon’ has also been used by songwriters to denote
feelings of sadness and loneliness.
The
geographical ‘blue moon’
Another usage has been its
literal meaning, indicating the actual physical color of the moon as it
appeared to observers. People have reported having seen a green sunset and a
blue moon after the explosion of Krakatoa, an Indonesian volcano, in 1883.
The volcanic dust from this explosion rendered the moon blue for almost two
full years. Later in 1927, in India, certain geographical conditions gave
the moon a blue color for a while. Huge forest fires in Newfoundland turned
the moon blue in 1951. This was the time when the phrase ‘once in a blue
moon’ came to be used. The phrase means – a fairly infrequent event.
|
