Halloween has always caused weird things and can be scary. But this year the Halloween night sky will be a special image, nothing to do with pumpkins or makeup. This is the Blue Moon, which will be revealed on October 31, 2020.
The name “Blue Moon” does not really mean that the Moon will emit a strange blue glow, but to explain a full moon. Normally the moon would be full once a month. But in October of this year, we will have 2 full moons: October 1 and October 31. The rarity of this phenomenon has resulted in the English expression once in a blue moon, meaning “very rare”. Because the blue moon is so rare, anyone who can see it is considered lucky!
It is known that the “blue moon” appearing on Halloween night is a rare event since WWII. This scene is estimated to occur every 2.5 years on average, but it takes 19 years to coincide with Halloween.
The image of the full moon used to decorate every Halloween made us think this is true. “Most of my students think that full moons happen every Halloween,” says Jeffrey Hunt, professor of astronomy.
But in fact, the last full moon fell on the Halloween day that was seen by the world was 1944. Over 10 years later, in 1955, the Halloween full moon has again appeared in many areas but without count the Northwest. America and the Western Pacific.
According to Earth Sky, when there are 2 full moons in a month (usually every 2.5 to 3 years, this phenomenon only happens once), the second full moon is called a “Blue Moon”. Additionally, “Blue Moon” also refers to the third or fourth full moon of a season.
But the second full moon in a month does not change the physical characteristics of the moon, so the moon’s color remains white gold, not blue, according to the US Aeronautics and Space Administration (NASA).
However, the Moon was also once blue, after the Krakatoa volcano erupted in Indonesia in 1883. At that time, the atmosphere was filled with dust particles and gases of certain sizes, making the Moon appear pale.
The blue moon on October 31 of this year is special because it falls on Halloween night. But that (the Halloween full moon) only happens once every 19 years.
People across America, Africa, all of Europe and much of Asia will be able to see this phenomenon.
While in Australia, people in the west can see the “blue moon”, but not the center and east of the country. If we ignore the “blue moon” that coincides with Halloween this year, we will have to wait until 2039 to be seen again.
It is also important to note that despite the name “blue moon,” the Moon does not change color like the blood moon that occurs during a total eclipse. The color of the moon will depend on the appropriate weather conditions.