1. This year’s Harvest Moon will be officially full at 2:40 p.m. Eastern Daylight Time on October 5 – this is when it is directly opposite of the sun. But will appear full for a day or two before and after.
2. In the 80 years between 1970 and 2050, the October full moon will only claim the Harvest Moon title in 18 of those years altogether. The last time was in 2009, and the next time will be in 2020. According to Space.com, October Harvest Moons come every three years on average, although as many as eight years can elapse between them.
3. Next year, we’ll be back to the more usual schedule, with the Harvest Moon occurring on September 24, a mere two days after the 2018 autumnal equinox.
4. Harvest moons can happen as early as September 8 or as late as October 7, making this year’s relatively late.
5. Sometimes the full moon happens on the equinox itself, the Harvest Moon last perfectly coincided with the autumnal equinox in 2010, and will do so again in 2029.
6. According to early Native American tradition, the calendar was marked by cycles of the moon and thus, each one has a seasonal significance and name. The October moon has been variously known as the Full Hunter’s Moon, the Travel Moon, and the Dying Moon.
For more info, go to https://www.treehugger.com/natural-sciences/11-things-know-about-years-special-harvest-moon.html