Thursday’s full moon will appear unusually large, and possibly orange. Here’s why.
October 5, 2017
The full moon will rise in the east, as always, Thursday, Oct. 5, over the Vail Valley. But it won’t be your typical full moon.
Thursday’s moon is referred to as the Harvest Moon because it’s the first full moon since the Sept. 22 autumnal equinox. The combination of “moon illusion” and the presence of dust in the sky also can make the Harvest Moon appear orange. It’s typically a pretty cool sight.
“The harvest moon gets its name from agriculture. In the days before electric lights, farmers depended on bright moonlight to extend the workday beyond sunset. It was the only way they could gather their ripening crops in time for market. The full moon closest to the autumnal equinox became "the harvest moon," and it was always a welcome sight.
“Northern summer changed to fall on Sept. 22, and is called the autumnal equinox. The word equinox comes from the Latin words for ‘equal night.’ The fall and spring equinoxes are the only days of the year in which the Sun crosses the celestial equator.
“Keep an eye on the moon as it creeps above the eastern skyline. The golden sphere may appear inflated. This is the moon illusion at work. This optical illusion is caused by the moon's proximity to distant objects. A harvest moon inflated by the moon illusion is simply beautiful to us, but even more so to the farmers getting their crops in on those cool autumn evenings.”
We’d love to see your best pictures of the Harvest Moon. Send to firstname.lastname@example.org or post on Instagram with #vaillive. Enjoy!