October's full moon, known as the Hunter's Moon, will occur at 10:57 a.m. EDT (1457 GMT) on Oct. 20, according to NASA.
For New York City observers, the moon will set that morning at 7:01 a.m. and rise that evening at 6:25 p.m. local time. The moon sets the morning of Oct. 21 at 8:03 a.m.
Another phenomenon that will accompany the full moon is the Orionid meteor shower, one of the most anticipated annual displays of "shooting stars" — although this year the bright moonlight will outshine all but the brightest meteors.
The Orionids are named after the constellation in which they appear to originate: Orion, the hunter. Orion is a winter constellation and one of the most distinctive with its three-star belt and collection of bright stars. The Orionids generally produce about 20 meteors per hour, and it is active from the last days of September all the way to the first week of November, though activity varies a bit from year to year. Orionid meteors are known for being fast and leaving persistent trails of ionized gas as they hurtle through Earth's atmosphere. The meteors will appear to come from the northeastern side of Orion, which gets high enough to see in mid-northern latitudes by about 10:30 p.m. local time. At that point the moon will still be high in the sky — from New York city it will be about 40 degrees above the east-southeast horizon.
Meteors are tiny particles of rock and ice that are as small as sand grains. Most meteor showers originate with comets; as comets swing around the sun they leave trails of dust and ice in their wake, and when the Earth passes near the comet's orbit, some of those particles hit the atmosphere and burn up, creating meteor showers. The Orionids originate with Halley's comet, which becomes visible to the naked eye every 76 years — it is due back in 2062.
When it becomes officially full the moon will be in the constellation Cetus, the whale, but by 10 p.m. local time on the night of Oct. 20 it will have moved into the constellation Pisces, the fishes. The moon will reach a maximal altitude of about 54 degrees at 12:27 a.m. (Oct. 21) in New York City.
Moving farther south, the moon's altitude will increase, and the timing of moonrise and moonset will change. An observer in Miami, for example, will see the just-past-full moon rise at 7:05 p.m. local time on Oct. 20 and reach a maximum altitude of about 75 degrees at 1:34 a.m. on Oct. 21, according to Time and Date. In Quito, Ecuador, the moon rises at 6:17 p.m. local time and reaches an altitude of 79 degrees at 12:27 a.m. on Oct. 21. If you want to see the full moon close to the zenith, you have to go to Panama City, Panama — at 12:33 a.m. local time on Oct. 21 the moon will be at an altitude of 88.4 degrees.
Farther south, the moon starts to drop in altitude again, but this time it is towards the northern rather than southern horizon. In Melbourne, Australia, the full moon will occur at 1:56 a.m. local time on Oct. 21. When the moon reaches its highest point in the sky at 1:07 a.m. it will be about 44 degrees high — similar to the view from New York City, though it will be in the opposite direction.
From the Southern Hemisphere the moon also appears to change position against the background stars slightly, because the moon is close enough to Earth that separating two observers by a distance approximating Earth's diameter — say the distance between New York and Melbourne — will cause a visible shift. Instead of Cetus, the moon will appear to be in the constellation Aquarius, the water bearer when it is full. The change in is less than a degree, but that's just enough to put the moon over the "border" between constellations.
On Oct. 20, the sun will rise in New York City at 7:12 a.m. local time. Mercury rises about an hour and a half before that, at 5:46 a.m local time, according to the skywatching site Heavens Above. By about 6:30 a.m. the planet will be just visible in the predawn sky, about 8 degrees above the east-southeast horizon. The sky will be getting light; Mercury will be hard to see.
Closer to the equator the situation is a little better; while the sun rises early in Bogota, Colombia, (5:41 a.m. on Oct. 20) Mercury rises at 4:40 a.m. local time and is still only about 8 degrees above the horizon at 5:10 a.m. local time. That said, as one moves south the path the sun takes across the sky makes a steeper angle with the horizon; this makes tropical sunrises and sunsets quick, and the sky is a bit darker in the hour before sunrise than in more northern (or southern) climes.
Venus will still be an "evening star" in the constellation Scorpius, the scorpion, setting at 8:09 p.m. local time in New York on Oct. 20, according to Heavens Above. Sunset is at 6:07 p.m., and at that point Venus is still about 15 degrees high in the southwest. Venus is bright enough that it is one of the first night-sky objects, besides the moon, to become visible as the sky darkens; by about 7 p.m. it is still high enough — about 7 degrees — to be easily seen. Southern Hemisphere locales will have a much better view. In Melbourne, for example, Venus doesn't set until about 11:39 p.m. local time. Sunset is at 7:42 p.m., and the planet should become visible by about 8:15 p.m. when it is still some 38 degrees above the western horizon.
Mars will be too close to the sun to be visible; it rises at 6:54 in New York on Oct. 20, just 18 minutes ahead of sunrise. The planet will become more prominent in the coming months, as it moves higher in the predawn sky.
Jupiter and Saturn will both be in the constellation Capricornus, the sea goat, and both planets will be about 30 degrees high in the south an hour after sunset in New York City. Saturn will be to Jupiter's right. The full moon will make the stars of Capricornus harder to spot, but the contrast with the two planets will be that much greater — they will be the only "stars" in the region visible from many urban areas. Both planets set after midnight; Saturn first at 12:23 a.m. local time on Oct. 21, Jupiter follows at 1:41 a.m. local time in New York City.
Stars and constellations
From mid-northern latitudes, looking directly up from the two giant planets, observers will see the stars Altair, Vega and Deneb to the left. These three stars form the Summer Triangle. By 11:30 p.m. local time in mid-northern latitudes the "base" of the triangle, consisting of Altair and Vega, appears almost parallel with the western horizon. Turning left from the Triangle will lead observers to the south, where the "wet region" of the sky, which is full of water-themed stellar groupings, will be front and center. Cetus and Pisces will be near their high points, and just to the west of Cetus is Aquarius. Since the moon will be full, all of these will be harder to make out as the moon is so bright it tends to wash out fainter stars. If you have a clear southern horizon by around midnight you can see the bright star Fomalhaut due south, below and to the left (east) of Jupiter. Fomalhaut is the brightest star in the southern constellation of Piscis Austrinus, and a relatively close neighbor to the sun, only about 25 light-years away.
Moving up (northward) from Cetus one can see the Great Square of Pegasus, which connects to the constellation Andromeda, which is not only the home of the eponymous galaxy (visible as a smudge of light, though the full moon makes it harder to spot) but also the woman who was saved by Perseus from Cetus the leviathan, and taken away on a flying horse for which Pegasus is named. The Andromeda Galaxy is easily visible on moonless nights, but with a full moon it is more difficult; it sometimes helps to look away from the moon for a few minutes.
The bright winter constellations become prominent in late October, with Orion and Taurus, the bull above the horizon in the east by midnight along with Gemini, the twins and Auriga, the charioteer; the four form a group of relatively bright stars that can be easily found by looking to Orion's belt.
How the "Hunter's Moon" got its name
While the October full moon is often called the Hunter's Moon, traditional names for the full moon reflect local environment and history; according to the Ontario Native Literacy Coalition, the Ojibwe people called the tenth full moon the "Falling Leaves Moon" or Biinaakwe Giizis. This full moon can also fall in September, lunations are 28.5 days long; the number of lunations in a given 10-month period can vary. The Cree people called it "Pimahamowipisim " (Migrating Moon) as that is when many animals in their traditional territory in Canada move as they anticipate winter.
In China, the full moon falls on the 15th day of the ninth month in the year of the Ox, which means it is Júyuè, or Chrysanthemum month.
Muslims celebrate Muhammed's birthday during the days just before and after the full moon of the third month in the Islamic calendar. The date varies by country, as they have differing traditions (and much as Orthodox Christians and Catholics celebrate Christmas on differing days, Shia and Sunni Muslims use different dates to commemorate the Prophet's birth). In Bangladesh, India and Indonesia the date will fall on Oct. 20, the same date as the full moon. Egypt, Kuwait and the United Arab Emirates celebrate it a day later, while Iran's public holiday is the 24th. Other Muslim-majority nations use Oct. 18 and Oct. 19.