Harvest moon: Why does the moon look so big?

Harvest moon: This month's full moon appears low in the southeastern sky, traditionally offering extra light so that farmers could gather their crops later into the evening.

The moon is seen behind decorative lights prepared for the upcoming Mid-Autumn or Moon Festival at a park in Hong Kong on Thursday. The festival falls on September 12 this year.

Bobby Yip/Reuters

September 12, 2011

If you're located in the Northern Hemisphere, you might have the opportunity to spot a special full moon in the sky this weekend: the Harvest Moon.

This month's special full moon gets its name because its appearance low in the southeastern sky for several nights historically afforded farmers extra time for harvesting crops. Before the invention of electricity, farmers relied on bright moonlight in the late summer to gather their ripening crops after sunset.

The moon typically rises about 50 minutes later each night, but during several nights around the Harvest Full Moon, it can rise between 25 to 30 minutes later across the United States. In other Northern Hemisphere locations, like Canada and Europe, the moon can rise just 10 to 20 minutes later around a Harvest Moon, according to SPACE.com's skywatching columnist Joe Rao. [Photos: Our Changing Moon]

For the past couple nights the moon has been well positioned in the sky as it heads into the full moon Sunday night (Sept. 11), with the peak coming on Monday (Sept. 12) at 5:27 a.m. EDT (0927 GMT).

Traditionally, the designation "Harvest Moon" is given to the full moon that happens closest to the autumnal (or fall) equinox, which occurs on Sept. 23 this year. While the Harvest Moon typically occurs in September in the Northern Hemisphere, it can occur in early October about once or twice each decade, according to Rao. [Infographic: Phases of the Moon Explained]

Skywatchers and amateur astronomers should hope for clear skies that will offer them nice views of the Harvest Moon. But, in addition to marveling at the bright sight, many detailed features on the moon can be seen with the ordinary binoculars or small telescopes.

Editor's note: If you snap an amazing photo of September's Harvest Moon and would like to share it with SPACE.com for a possible story or gallery, please contact managing editor Tariq Malik at: tmalik@space.com.

Follow SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcom and on Facebook.