How many times have you heard people saying that something or the other happens ‘once in a blue moon’? Well, tonight is when they would have to deliver!
India and Australia are among the countries who could witness a blue moon tonight, but for those of us in Mumbai, torrential rains are bound to kill any chance of witnessing this landmark event.
For more, read this ANI report from Sydney: For those interested in astronomy, Saturday (June 30) could be a landmark day, for they will be in a position to cite a `Blue Moon'.
According to a Sydney Morning Herald report, the "Blue moon" is a quirky astronomical term used to describe the second full moon in a calendar month, an event which occurs only once every two and a half years.
But it hasn't always been this way. Up until the 1940s, the term blue moon was used to describe the third full moon in a season.
However you define it, a blue moon isn't a common event. On average they occur once every two and a half years, which probably led to the term 'once in a blue moon'.
So if the moon doesn't change colour, why use the term 'blue'?
Geoff Wyatt, Manager of the Sydney Observatory, believes it probably has more to do with how the moon might 'feel', rather than its colour.
According to Wyatt, a blue moon isn't likely to attract the attention astronomers. In fact for many, it's an annoyance.
"The bright light of a full moon washes out the sky making faint stars hard to see. It's also difficult to locate mountains and craters on its surface. Full moon is the worst time to view the moon," Wyatt says.
Despite a blue moon being of little interest to astronomers, it has plenty of meaning for others.
"A blue moon signifies a rare occurrence ... when magic is possible," says Stephanie Calkin, the organiser of the Under The Blue Moon street festival.
The festival started in 2004 in inner-Sydney Newtown - an area known for it's goths and alternative cultures.
Because of differing timezones and the international date line, the full moon that will occur on 30 June is only 'blue' for Europe, Africa, Asia and Australia.
New Zealanders will have to wait until 30 July for their blue moon, while North and South America had theirs at the end of May.
Australia will get its next blue moon on New Year's Eve 2009. (ANI)