Editor's note: The partial lunar eclipse of 2023 is over but you can see amazing video of its peak here. Read our wrap story for more stunning lunar eclipse photos.
The full moon of October, called the Hunter's Moon, will grace the skies on Oct. 28 at 4:23 p.m. Eastern Daylight Time (2023 UTC), according to the U.S. Naval Observatory, when it will undergo a partial lunar eclipse visible from Europe, Asia, Africa, Oceania, and the far eastern edges of North and South America.
Eclipses always tend to occur in pairs; there was an annular solar eclipse on October 14; solar eclipses can happen when the moon is in the new phase, between the sun and the Earth. When the moon is full – on the opposite side of the Earth from the Sun – we can see lunar eclipses if the moon passes through the Earth's shadow. Eclipses don't happen every time there is a new moon or full moon because the moon's orbit is slightly inclined to the plane of Earth's orbit, so most of the time the moon "misses" the Earth's shadow and the Earth misses the moon's shadow. When the moon lines up to create a solar eclipse, it also does so for a lunar eclipse; this is why the two types of eclipses tend to occur together.
As it is a partial eclipse, only a small part of the moon will be darkened by the Earth's umbra, the darkest part of the Earth's shadow. (If one were standing on the moon, being in the umbral shadow would mean you are in a place where the sun is completely blocked by the Earth). In places where the umbral phase is visible it will look as though a small "bite" of the moon is taken out. Most of the moon will be in the penumbra, the lighter part of Earth's shadow that makes the moon look slightly darker – some people see it as a bit "brown" – but not enough for most observers to notice.
Unlike solar eclipses lunar eclipses are visible wherever the moon is above the horizon as it passes through the shadow of the Earth. In this case the eclipse begins at 1936 UTC, (3:36 EDT) which is evening in Europe and Africa. In London, where the umbral phase of the eclipse starts at 8:36 p.m. British Summer Time, the moon is about 28 degrees high just south of east. The "bottom" of the moon will appear to darken, and by 9:15 p.m. local time some 12% of the moon will be in shadow. I
In Cape Town, the umbral phase starts at 9:35 p.m. local time and the maximum eclipse is at 10:14 p.m. In the Southern Hemisphere, where the moon will appear in the northern half of the sky, the Earth's shadow will appear to graze the upper right quadrant of the moon and move to the left. The umbral eclipse ends at 10:52 p.m.
As one moves east the eclipse occurs later. In New Delhi, for example, the umbral phase starts at 1:05 a.m. local time on October 29 and ends at 2:22 a.m. For observers further east, the eclipse happens in the morning hours of Oct. 29.
At the extreme ends of the eclipse's zone of visibility the eclipse happens as the moon rises or sets. In St. Johns, Newfoundland, for example, the umbral eclipse starts at 5:05 p.m. local time but the moon does not rise until 5:40 p.m.; the maximum eclipse is at 5:44 p.m. and the moon comes out of the umbra at 6:22 p.m. On the other side of the world, in Tokyo, the moon touches the dark part of Earth's shadow at 4:35 a.m. local time, with the maximum eclipse at 5:14 a.m. The umbral phase of the eclipse ends at 5:52 a.m., just 14 minutes before the moon sets.
Visible planets in October
Even for those that miss the lunar eclipse, October's full moon will be close to the planet Jupiter in the sky; From New York City, as the moon rises at 5:59 p.m. Eastern Time, Jupiter will follow 14 minutes later, at 6:11 p.m. The two will appear to move closer as the night progresses, until by 4:14 a.m. October 29 they are in conjunction, with the moon appearing just above and to the right of Jupiter as both move lower in the west.
Saturn, meanwhile, by 8 p.m. will be due south at an altitude of about 35 degrees; the planet reaches its highest point, crossing the meridian at 8:41 p.m., and it sets at 1:57 a.m. on October 29. Venus, meanwhile, rises at 3:29 a.m. in New York and in the hour just before dawn is one of the brightest objects in the sky, barring the moon. By 6 a.m. it is 27 degrees high in the east.
From the Southern Hemisphere, the conjunction between the moon and Jupiter will appear "reversed" with Jupiter below and to the right of the moon. Saturn, meanwhile, reaches an altitude of 69 degrees from Santiago, Chile, when it crosses the meridian at 9:27 p.m. October 28. The Jupiter-moon conjunction happens at 5:14 a.m. local time.
October stars and constellations
In mid-northern latitudes – locations such as New York, Chicago, Sacramento or Madrid -- by about 9:30 p.m. on Oct. 28, the Summer Triangle is still visible, but it is in the western half of the sky. Deneb is the brightest star in Cygnus the Swan, and the highest of the three stars that make up the asterism. Below and to the right of Deneb will be Vega, in Lyra the Lyre, and to the left is Altair, the "eye" of the Eagle. Meanwhile, moving left (towards the south) one will see Fomalhaut, the alpha star in Piscis Austrinus, the Southern Fish. Fomalhaut will be below and to the left of Saturn.
Looking towards the northeast, Capella, in Auriga, the Charioteer, will be rising, and it ushers in the winter stars. In fact, as one turns towards the close-together moon and Jupiter, one can look below the pair close to the eastern horizon and see Aldebaran, the brightest star in Taurus the Bull, a prominent winter constellation as it is next to Orion, which gets fully above the horizon by 11 p.m.
Turning further north (left) and upwards from Capella, the "W" of Cassiopeia is visible, which one can use to find Polaris, the Pole Star, in Ursa Minor. While there are no "pointers" in Cassiopeia as there are in the Big Dipper, if one draws a rough line from the middle peak of the "W" to the left and downwards, one will reach Polaris. The Big Dipper, meanwhile, will be close to the horizon, and will become more visible as the hours pass.
For Southern Hemisphere sky watchers, looking southeast at about 10 p.m. in Santiago, Chile, one will see Achernar, the alpha star of Eridanus the River, which winds across the sky all the way to near the feet of Orion. Below Eridanus, low in the southeast, will be Canopus, the brightest star in Carina, the Keel. If one looks due south and turns a bit to the right (towards the southwest) one can see Alpha Centauri, also known as Rigil Kentaurus.
The October full moon is often called the Hunter's Moon, according to the Old Farmer's Almanac, because it happens when hunting for many game animals begins. Not every culture saw it that way, though; according to the Ontario Native Literacy Coalition, the Anishinaabe people called October's full moon the "Mskawji Giizis," or the Freezing Moon, because October is when the first frosts occur in their traditional territory in the Great Lakes region. For traditional Chinese calendars Oct. 28 is in the 9th lunar month, called Júyuè or Chrysanthemum Month, as it is when the flower of that name tends to bloom.
The Maori of New Zealand had a lunar calendar that calls the lunation from October to November Whiringa-a-rangi, and they called it one of the summer months, while the night of the full moon is called Rākau-nui.
How the "Hunter's Moon" got its name
The October full moon is often called the Hunter's Moon, according to the Old Farmer's Almanac, because that moon occurs when the season for hunting many game animals begins. Traditional names for the full moon often reflect local environment and history; according to the Ontario Native Literacy Coalition, the Ojibwe people called October's full moon the "Mskawji Giizis," or the Freezing Moon, because October is when the first frosts occur in their traditional territory in the Great Lakes region. The Cree people called it "Pimahamowipisim" (Migrating Moon), as in North America, many bird species start migrating south for the winter in mid-autumn.
In the Pacific Northwest, the Tlingit called the October full moon "Dís Tlein" (Big Moon), while the Haida called the moon "Kalk Kungaay," or the Ice Moon, according to the "Tlingit Moon and Tide Teaching Resource" published by the University of Alaska Fairbanks.
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Jesse Emspak is a freelance journalist who has contributed to several publications, including Space.com, Scientific American, New Scientist, Smithsonian.com and Undark. He focuses on physics and cool technologies but has been known to write about the odder stories of human health and science as it relates to culture. Jesse has a Master of Arts from the University of California, Berkeley School of Journalism, and a Bachelor of Arts from the University of Rochester. Jesse spent years covering finance and cut his teeth at local newspapers, working local politics and police beats. Jesse likes to stay active and holds a fourth degree black belt in Karate, which just means he now knows how much he has to learn and the importance of good teaching.