September 17, 2013
A Harvest Moon Rises Wednesday – Some Factoids To Impress Your Friends
[ Watch the Video: Sky Watchers Can Catch The Harvest Moon Tonight? ]
Brett Smith for redOrbit.com - Your Universe OnlineThere’s a reason why the character Linus from the cartoon Peanuts has never been able to catch a glimpse of the Great Pumpkin for all these years – he’s probably been a month too late all along. Expert skywatchers know the Harvest Moon, which happens every September near the autumnal equinox, is the most likely full moon to provide a large pumpkin-like moon hanging just above the horizon.
According to NASA, the best time for viewing this year’s Harvest Moon will be right around sunset on Wednesday night.
The Harvest Moon isn’t unique in that each of the twelve full moons of the year have a special name according to folklore: the Wolf Moon (January), the Snow Moon (February), the Worm Moon (March), the Sprouting Grass Moon (April), the Flower Moon (May), the Strawberry Moon (June), the Thunder Moon (July), the Sturgeon Moon (August), the Harvest Moon (September), the Hunter's Moon (October), the Beaver Moon (November), and the Long Night's Moon (December).
[ Watch The Video: What Is The Harvest Moon? ]
Before artificial light came into use, farmers had to use moonlight to harvest their crops after the summer growing season. As many crops ripen around the same time, farmers are extremely busy during this time of year and many are forced to work after sundown. In the past, moonlight became a necessary part of farming. Thus, the Harvest Moon was born.
During most of the year the year the Moon rises about 50 minutes later each day. However, near the autumnal equinox each September – the difference contracts to around 30 minutes. This is due to the moon's orbital path, taking it at a narrow angle along the evening horizon.
While this might sound like a bit of useless trivia – it makes a big difference with respect to celestial viewing, since for several nights in a row, the Harvest Moon rises right around sunset.
This annual timing makes the low-hanging moons appear reddened by the combination of sunlight, clouds and atmospheric dust. Additionally, due to an optical illusion, a moon appearing near the horizon looks swollen to an unusually large size. The result of all these factors is that a Harvest Moon often looks like a giant pumpkin, which can be seen for several nights around the time of the autumnal equinox.
In addition to being a spectacle all its own, birdwatchers know that the Harvest Moon provides an additional benefit – shedding a second light on the horizon that helps for watching migrating birds. Some previous research has shown that birds use the Harvest Moon to migrate from one place to another. Research has also shown that the birds will wait for the Harvest Moon to begin their migration.
The Harvest Moon has also captured the popular imagination in everything from video games to types of beer that have been named in its honor. Even rock and roll legend Neil Young penned a ballad about the annual autumnal event, writing: “We could dream this night away/ But there's a full moon risin'/ Let's go dancin' in the light/ We know where the music's playin'/ Let's go out and feel the night.”