Near sunset on Saturday evening, September 17, the Harvest Moon will be seen rising just slightly south of the eastern point on the horizon. It will appear unusually large since it will be only about a day-and-a-half past perigee.
The Harvest Moon is the Full Moon that occurs nearest to the moment of the Autumnal Equinox, which is September 22 this year. It provides the moonlight for farmers to continue harvesting into the evening. This is true for several nights in a row because of the sharp angle the ecliptic strikes the horizon at sunset during this time of the year. The geometry allows the Moon to rise only a short time later during successive evenings. This will be especially true in Septembers 2005 and 2006 since the Moon will be in the zone of its 18.6-year nodal cycle during which the effect is exaggerated.
On average, the Moon rises 50.47 minutes later each day. But printed below are the Moon’s CDT rising times as viewed from Chicago’s Adler Planetarium later this month.
Sep 17 – 18:58
Sep 18 – 19:21 – 23 minutes later than the previous evening
Sep 19 – 19:44 – 23 minutes
Sep 20 – 20:09 – 25 minutes
Sep 21 – 20:38 – 29 minutes
If you’re not a farmer, then get ready to enjoy the beauty of the rising Harvest Moon. If you are one, then prepare to get to work.