Full Supermoon September 2015: Harvest Moon, Fourth Blood Moon Eclipse

Summary: The full supermoon September 2015 exemplifies a quartet of lunar spectacles as harvest moon, fourth blood moon, supermoon and totally eclipsed moon.

blood moon eclipse: coppery red of total lunar eclipse as light from all of Earth's sunrises and sunsets colors the moon's surface: Krista Lundgren/USFWS Mountain-Prairie, CC BY 2.0, via Flickr

September 2015’s full moon exemplifies a trio of lunar spectacles, all depicted with a super-sized flourish.

As a full supermoon, the full moon appears unusually large due to orbital proximity to Earth.

As a harvest moon, the first full moon appears closest to the autumnal equinox, which occurs in 2015 on Wednesday, Sept. 23.

As a blood moon eclipse, September's full moon numbers among four in-a-row total lunar eclipses (April 15, 2014; Oct. 8, 2014; April 4, 2015; Sept. 27/28, 2015) spaced at six full moon intervals.

A full supermoon occurs when the full moon appears exceptionally large because the center-to-center distance between Earth and moon measures less than 224,834 miles (361,836 kilometers). The moon turns into a full supermoon at 2:51 Coordinated Universal Time, Monday, Sept. 28 (10:51 p.m. Eastern Daylight Time, Sunday, Sept. 27).

Full supermoon is a popular descriptor for a close full moon, known as perigee full moon in astronomy. Perigee (Ancient Greek: περί, perí, “near” + γῆ, gê, “Earth”) designates the closest, center-to-center, distance between two celestial bodies.

Annual proxigee represents the year’s closest perigee, or closeness, of the moon’s center to Earth’s center. Appearing as the second of a trio of three-in-a row full supermoon months, September’s full supermoon orbits sufficiently close to Earth, at a center-to-center distance of 221,753 (356,877 kilometers), to rank as 2015’s proxigee full moon. Proxigee occurs at 1:47 UTC, Sept. 28 (9:51 p.m. EDT, Sept. 27), closely preceding the supermoon's cresting at fullness by a little over one hour.

Names for the year's parade of full moons come from Native Americans, such as the Algonquin tribes of the Great Lakes, St. Lawrence River and Atlantic coast. The first full moon closest to the autumnal equinox, which occurs annually Sept. 22, 23 or 24, is nicknamed as the harvest moon in recognition of the readiness of plentiful harvests of such Native American staples as beans, corn, pumpkins, squash and wild rice.

The Northern Hemisphere's harvest moon may appear anywhere within a four-week period of two weeks before to two weeks after the autumnal equinox. The late end of the appearance spectrum for the harvest moon may stretch into early October, which happened most recently Oct. 4, 2009, and which next occurs Oct. 5, 2017.

As a popular term, blood moon eclipse seemingly refers to a lunar tetrad (Ancient Greek:  τέσσαρες, téssares, “four”) of four in-a-row total lunar eclipses. Each eclipse is separated by an interval of six full moons.

Blood moon eclipse also refers to a total lunar eclipse of straight-line formation of sun, Earth and moon. The sun is poised as a hidden backdrop rimming the Earth’s circumference with sunrises and sunsets that bathe the moon with a coppery red glow.

September's full moon supermoon also passes through Earth's shadow for an array of eclipses: penumbral, partial and total. The lunar eclipse timeline spans 4 hours 15 minutes.

At 00:12 UTC (08:12 p.m. EDT), the moon begins entrance into Earth’s penumbra (Latin: paene, “almost” + umbra, “shadow”), or outer part of Earth’s shadow.

At 01:08 UTC (09:08 p.m. EDT), the partial eclipse starts as the moon begins entrance into Earth’s umbra (Latin: “shade”).

At 02:12 UTC (10:12 p.m. EDT), the total eclipse begins as the moon is fully within Earth’s umbra.

At 02:48 UTC (10:48 p.m. EDT), the event reaches greatest eclipse. Greatest eclipse references the instant of the closest lunar passage to the axis of Earth's shadow.

At 03:23 UTC (11:23 p.m. EDT), the total eclipse ends as the moon begins exit from Earth’s umbra.

At 04:27 UTC (12:27 a.m. EDT), the partial eclipse ends as the moon fully exits from Earth’s umbra.

The area of visibility stretches from North and South America to Europe and Africa and also includes parts of West Asia as well as the eastern Pacific.

Total Lunar Eclipse September 2015 visibility map: Fred Espenak/NASA Goddard Space Flight Center, CC BY 2.0, via NASA

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

blood moon eclipse ~ 2nd of 2014-2015 blood moon tetrad occurred Oct. 8, 2014, as a full hunter moon ~ viewed from McIntosh County, Kulm Wetland Management District, North Dakota: Krista Lundgren/USFWS Mountain-Prairie, CC BY 2.0, via Flickr @ ttps://www.flickr.com/photos/usfwsmtnprairie/15474648641/

total lunar eclipse September 2015 visibility map: Fred Espenak/NASA Goddard Space Flight Center, CC BY 2.0, via NASA @ http://eclipse.gsfc.nasa.gov/lunar.html

For further information:

Espenak, Fred. "Total Lunar Eclipse of 2015 Sep 28." NASA > Lunar Eclipse Page. Last updated 2015 Jan 08.
Available @ http://eclipse.gsfc.nasa.gov/lunar.html

Ford, Dominic. "Total lunar eclipse, September 2015." In-The-Sky.org > Astronomy News > Sky Notes > The Earth-Moon System > Eclipses. Last updated Tue Sep 22 17:13:59 2015 UTC.
Available @ https://in-the-sky.org/news.php?id=20150928_10_100

Marriner, Derdriu. "First Total Lunar Eclipse of 2015 Occurs as Blood Moon on Holy Saturday, April 4." Earth and Space News. Friday, April 3, 2015.
Available @ https://earth-and-space-news.blogspot.com/2015/04/first-total-lunar-eclipse-of-2015.html

Marriner, Derdriu. "Total Lunar Eclipse 2015 Cloud Cover: Clear for Central and Western US." Earth and Space News. Saturday, Sept. 26, 2015.
Available @ https://earth-and-space-news.blogspot.com/2015/09/total-lunar-eclipse-2015-cloud-cover.html

McClure, Bruce. “Most ‘super’ supermoon of 2015 on September 28.” EarthSky > Tonight. Sep 22–Sep 28. Sept. 26, 2015.
Available @ http://earthsky.org/tonight/most-super-supermoon-of-2015-on-september-28

McClure, Bruce, and Deborah Byrd. “What is a Blood Moon?” EarthSky > FAQS > Human World > Space. Sept. 22, 2015.
Available @ http://earthsky.org/space/what-is-a-blood-moon-lunar-eclipses-2014-2015

"September 27/28, 2015 -- Total Lunar Eclipse." Time And Date > Sun & Moon > Eclipses.
Available @ https://www.timeanddate.com/eclipse/lunar/2015-september-28

Vivola, Jean. “One-night lunar spectacular nears – harvest moon, supermoon and blood moon eclipse.” WGAL.com > Weather. Sept. 21, 2015.
Available @ http://www.wgal.com/weather/onenight-lunar-spectacular-nears-harvest-moon-supermoon-and-blood-moon-eclipse/35388748