Thursday, December 31, 2009

Blue Moon North Fife

Blue Moon over Dundee this evening. An event that happens once every, It's when there are two full moons in one month. "Blue moon" is a nickname for the second full moon in a month.
Full moons happen about every 29.53 days (the precise average period is 29.53059 days,but it's not always that exact interval because there are variations through the year' as the Earth-moon distance, Earth-sun distance, and sun-moon distance change)So you'll get a blue moon in a 31-day month if and only if the first full moon occurs less than 1.47 days into the month, which'll happen, on average, 1.47 / 31 of the time... or about 5% of 31-day months.
Similarly, in a 30-day month you get a blue moon every .47/30, or 1.5%.
These chances work out to a blue moon every 19 months, on average. It varies widely, however, and you can have several years without a blue moon at times.
You can't ever have a blue moon in February, since at most it has 29 days.

Partial eclipse, see a nibble out of the disc at 4 to 5 o'clock.

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