Astronomy enthusiasts will have the opportunity to see the blue moon on August 31. This is the last chance for this amazing phenomenon which occurs once every 3 years.
Ms. Hang on Friday, August 31, will not be as green as the name suggests, unless clouds of dust or ash in the atmosphere give it a special color. In general, a blue moon is not a name based on color, as the moon will remain colored like on other occasions.
The term blue moon again means full moon. For example, in the first half of the 20th century, a blue moon signified the third full moon of a season – winter, summer, fall, or spring – meaning there were four moons in a season instead of three.
However, this concept has been misunderstood for many years. Today we call the second full moon of the month “blue moon”.
Normally, a blue moon appears every 2.7 years on average. Sometimes the time to onset is shorter. For example, in 1999 a blue moon appeared in January and March (and there was no full moon in February).
The reason for the blue moon is that the calendar months do not correspond to the lunar months. A full moon cycle lasts 29 days, while a solar day typically has 30 to 31 days, so there are two full moons that occur in the same calendar month.
