A blue moon will appear in the sky on August 31, the 15th day of the seventh lunar month, the Ghost Festival (Photo)

According to astronomical experts, on August 31, which is the Ghost Festival on July 15, if the night sky is clear, a blue moon will appear in the sky and citizens will be able to enjoy a white and full "blue moon".

A blue moon will appear in the sky on August 31, the 15th day of the seventh lunar month, the Ghost Festival (Photo)

According to astronomical experts, on August 31, which is the Ghost Festival on July 15th, if the night sky is clear, a blue moon will appear in the sky and citizens will be able to enjoy a white and full "blue moon".

It has been calculated that a "blue moon" appears on average once every 32 months. For example, there was a full moon on the 2nd of this month, and there will also be a full moon on the 31st, which is a 'blue moon'. The next time this relatively rare calendar phenomenon occurs will be in July 2015.

"Blue Moon" is not a blue moon, it is just a name in the calendar. Li Defan, director of the planetarium, explained that in the Western astronomical calendar, when there are two full moons in a month, the second full moon is given a mysterious and romantic name - "blue moon".