Tonight’s Supermoon is also a Harvest Moon, which means that the full moon will be closest to the autumnal equinox. On a normal full moon, the celestial body rises around the time when sun sets in the east and is in the sky all night long and sets at sunrise. The speciality of the harvest moon is that the moon appears to travel close to the horizon in its path across the sky.
While it’s not yet autumn, the harvest moon earned its place in lunar tradition because moon rises several days before and after happen closer to sunset. The name Harvest moon came from Native Americans of the northern and eastern part of North America who kept track of the seasons by naming the recurring full moons and their months.
In the preelectric times, the harvest moon allowed farmers to reap their crops for a longer period as moon illuminated the fields. The early Harvest Moon also qualifies as a super moon because it turns full less than one day after the moon reaches its closest point to Earth for the month.
The moon will also be considered a supermoon, as EarthSky reported, “because the moon turns full less than one day after reaching lunar perigee — the moon’s closest point to Earth for the month.”
During the moon’s perigee, it is approximately 30,000 miles closer to Earth, making full moons during this period appear beautifully swollen in the night sky. What makes tonight supermoon special is that this will be the last supermoon of 2014. The perigee, and the series of supermoons that arrive with it, won’t return until 2015.
From year to year, the harvest moon can shine in either September or early October, depending on which month’s moon shines closer to the autumnal equinox. After the equinox, nights will become longer than days. You can watch the live webcast here.