On Friday the 13th, a rare astronomical sight will be overhead. A red harvest moon will occur in line with the thirteenth day of the month, as well as falling on a Friday.
In classic superstitious tradition, having it fall on a Friday is particularly inauspicious.
Likewise, folklore holds that the full moon brings out the “crazy” in people, as seen in ancient myths of the werewolf. Having the two overlap, while also being a red harvest moon, is exceedingly rare indeed.
If you’re remotely interested in stargazing, astrology or just unique dates, tomorrow will be a big day.
The term “harvest moon” has a specific meaning, and isn’t just a term that refers to a full moon in fall. Harvest Moon, historically, refers to the closest full moon to the Autumnal Equinox. Typically, this full moon is visible much sooner in the evening, and for much longer, than other full moons throughout the year.
This is due to the Earth’s elliptical orbit and slightly crooked axis. Because of the apparent luminosity and size of the moon during this time of year, farmers were able to work later into the evening under the moonlight. This was helpful, considering this is the time of year when the harvest needs to be brought in.
Thus, the name stuck: to this day, we call the full moon closest to the Equinox the Harvest Moon.
Friday the 13th is historically seen as an unlucky day in American folklore. The last time a full moon occurred on the thirteenth day of the month and a Friday simultaneously was in October of 2000, nearly twenty years ago.
Following tomorrow, the next time this will happen will be in October of 2049, three decades from now.
Even more interestingly, this full moon will appear as a “micro-moon,” as the moon is nearing its furthest point along its orbit from Earth. This is known as the moon’s apogee and makes it appear much smaller in the sky than it normally does.
So, get ready for a unique and rare astronomical phenomenon tomorrow!