Huge 'Harvest Moon' Rises This September -- What You Need To Know

To signal the end of summer and start of autumn this year, the Harvest Moon will rise this Sept. 16. Here are fast facts you should know about this rare occurence.

What is Harvest Moon?

Harvest Moon or September's full moon is the full moon that occurs nearest the automnal equinox.

Why is it called Harvest Moon?

Space.com notes that this phenomenon is called Harvest Moon because many crops tend to ripen in the late summer and early fall in the Northern Hemisphere. In earlier days, farmers depended heavily on this moon's light, working late into the evening to harvest their crops. Moonlight became an essential part of farming; thus, the name Harvest Moon.

What makes it special?

The old farmer's almanac suggests that the Harvest Moon is unlike any other moons which rises about 50 minutes later each day. Harvest Moon rises an average of 30 minutes later each day, much shorter than the usual. The early rising of the moon when dark falls is what makes every Harvest Moon special.

A more scientific explanation was given by Earth Sky: "The reason is that the ecliptic -- or the moon's orbital path -- makes a narrow angle with the evening horizon around the time of the autumn equinox. The narrow angle of the ecliptic results in a shorter-than-usual rising time between successive moonrises around the full Harvest Moon."

It is also referred to as Pumpkin Moon

When Harvest Moon rises earlier during sunset, it tends to be shaded with clouds and dust. Since it usually hangs low, it may also appear bigger because of optical illusion.

A video by NASA explains that combining the two conditions together, the Harvest Moon may appear like an orange pumpkin. Phys.org explains, "We're seeing them through the maximum thickness of atmosphere, which absorbs blue light and transmits red light."

Best time to see it

For this year, the Harvest Moon will pass through the very outer region of the Earth's shadow in what is known as a penumbral eclipse. The closest full moon to the autumn equinox reaches the crest of its full phase on Sept. 16 at 19:05 Universal Time -- continental U.S. at 3:05 p.m, Eastern Daylight Time at 2:05 p.m., Central Daylight Time at 1:05 p.m., Mountain Daylight Time or Pacific Daylight Time at 12:05 p.m, Earth Sky notes.