This Monday, August 19, 2024, a full blue supermoon in the sign of Aquarius will peak at 2:26 p.m. ET.
But what exactly is a Blue Moon, what does it mean and when can we expect to see one again?
Read on to learn more.
What is a Blue Moon?
Blue moons fall into one of two categories.
The lunar cycle lasts 29.5 days, making it a hair – or moonbeam – shorter than the average length of a calendar month.
Therefore, it may happen that a full moon occurs at the beginning of a month, leaving enough time for another one later.
According to the modern definition, when two full moons occur in a month, the second full moon is called a Blue Moon, monthly Blue Moon, or calendar Blue Moon.
A seasonal blue moon is defined as the third of four full moons in a season.
How often do blue moons occur?
Astronomically speaking, blue moons rise fairly regularly, about every two to three years.
Interesting fact: Since there are about 29.5 days between two full moons and February has on average only 28 and at best 29 days, there will never be a Blue Moon in the calendar.
Are Blue Moons Ever Really Blue?
A Blue Moon is not actually blue in color, although on very rare occasions it may appear blue due to atmospheric conditions caused by large wildfires and/or severe volcanic eruptions.
When the Indonesian volcano Krakatoa erupted in 1884, a huge cloud of ash and dust was thrown 80 kilometers into the stratosphere.
These ash particles acted like a filter, scattering red light and making both the moon and the sun appear blue-green.
Blue Moon in August
On Monday, August 17, we experience a seasonal Blue Moon—the third of four full moons that rise between the summer solstice and the autumn equinox.
After Monday’s lunation, we won’t see another Blue Moon until May 31, 2026, when one will rise and shine in the sign of Sagittarius.
Why is it called the Blue Moon?
The term “Blue Moon” is commonly attributed to two monks in the 16th century who published a scathing pamphlet critical of the Roman Church.
The two argued that the common man tends to believe every word of the clergy without worry, even if it is such absurd suggestions or statements as “the moon is blue” or “the moon is a cheese ball”.
Over time, the term lost its derogatory undertone and became associated with the rare and unusual, if not the completely absurd.
But how did the jump between a criticism of religion and the second full moon in a calendar month come about?
An explanation given in the Farmer’s Almanac connects blue with the Old English belewwhich means “betray”.
The almanac argues: “Perhaps … the moon was ‘belewe’ because it contradicted the usual perception of one full moon per month.”
Unlike other monthly or seasonal moon names – Buck, Strawberry, Harvest, etc. – the Blue Moon is not limited to a specific time of year or astrological season.
Astrology 101: Your Guide to the Stars
Astrologer Reda Wigle explores planetary constellations and their impact on each zodiac sign and reports on them irreverently. Her horoscopes integrate history, poetry, pop culture and personal experiences.
