Earth will spot a rare Blue Moon on October 31, that is, Halloween, for the first time in 76 years.
Blue Moon is also the second of the two full Moons to occur in a single calendar month. The last of this Moon by this definition of the term happened on March 31, 2018.
However, the last time humans spotted the Blue Moon on Halloween day, Oct. 31, was 1944.
Knowing the Blue Moon
As NASA says, the eventful Moon is the next full moon in a calendar month. Usually, months have just one full moon, but seldom a second one sneaks in.
Full moons are parted by 29 days, while most months are 30 or 31 days long, so it is likely to fit two full moons in a single month. This event occurs every two and a half years, on ordinary.
Contradictory to its name, a Blue Moon typically looks like it would on any other day. The duration of a full moon, all by itself, does not alter the moon’s color. Thus, the moon on Oct. 31 will also be pearly-gray, as usual.
However, there was a moment, not long ago, when mortals saw blue moons nearly every night. Half moons, crescent moons, or full moons were all blue, except when they were green.
The Moon of Halloween 2020
Halloween is shaping up much uniquely this year due to the coronavirus pandemic. Some cities choose to cancel trick-or-treating to lessen the virus’s risk of increasing from one household to another.
— AccuWeatherAstronomy (@AccuAstronomy) October 14, 2020
But in communities where young masqueraders will be going door-to-door collecting candy, they will have a gorgeous full moon to help brighten the way.
This time, it won’t be the regular full moon, either — it will be a blue moon.
Once in a Blue Moon
In October, the first full moon emanated on the first of the month and was one of the most reputable full moons of the year: The Harvest Moon.
The Harvest Moon is the nickname attributed to the full moon nearest to the fall equinox and typically gleams in September, but 2020 was one of the situations where it appeared in early October.
Blue moons like the one this month occur about once every two-and-a-half years. This shift is how the phrase “once in a blue moon” came to be.
Those who are superstitious may want to carry around a good luck charm on Oct. 31 and keep it handy with a Friday the 13th right around the corner in November.
Image courtesy of muratart/Shutterstock