Source: The Mercury, 29 January, 1999, p.3 Source: The Mercury, 29 January, 1999, p.3
THE world is preparing for two once-in-a-blue-moon experiences this year-for the first time in almost 40 years. Not since 1961 has the Earth experienced two "blue moons"- when two full moons occur in a single calendar month - in the same year. Before that, the pre- vious time was in 1885. The first blue moon of this year will occur on Sunday, when the full moon makes its second Janu- ary appearance. March will also have two full moons: March 1 and 31. The rarity is not expected to cause any major natural effects. "There has been a lot of interest on whether it is a natural phenomenon but it really is just a case of timing," Australian Sur- veying and Land Information Group spokesman Danny Gal- braith said. "But it is unusual for two to occur. "It can only happen that we get two in a year if the moon phases are perfect in January and March and February has 28 days." The January full moon is some- times known as "old moon" or "moon after yule", while the first March full moon is known as "sap moon", "crow moon" or "Lenten moon". Blue moons and full moons have long been associated with mysti- cal rituals, changes in tempera- ment and unexplained behaviour. "Blue moons were considered unlucky and a real nuisance, as they occurred at various times of the year and upset the scheduling of church festivals," Mr Galbraith said, adding that there was noth- ing unnatural about them. "It really is only a calendar effect. There is a full moon every 29 1/2 days, whether we like it or not, and there is no change on what the moon phase is doing. "So we can probably blame old Julius [Caesar, who instituted the Julian calendar on which the modern calendar is based]. If we'd had 30-day months, we probably wouldn't have had it at all." The next year with two blue moons will be 2018 and there will be another towards the end of the 21st century. AAP
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Index - Chance and Basic Probability