The Next Full Moon is the Cold, Frost, or Winter Moon; the Long Night Moon; the Moon after Yule; the Datta Jayanti and Thiruvathira Festival Moon; Unduvap Poya; and the Chang’e Moon.

The next full Moon will be Tuesday evening, December 26, 2023, appearing opposite the Sun (in Earth-based longitude) at 7:33 PM EST. This will be on Wednesday in Coordinated Universal Time (UTC) and for most of Eurasia, Africa, and Australia. Many commercial calendars use UTC and will show this full Moon on Wednesday. The Moon will appear full for 3 days, from Monday evening to Thursday morning.

The Maine Farmers’ Almanac began publishing “Indian” names for full Moons in the 1930s. Over time these names have become widely known and used. According to this almanac, as the full Moon in December this is the Cold Moon, due to the long, cold nights. Other names are the Frost Moon, for the frosts as winter nears or the Winter Moon.

As the full Moon closest to the winter solstice, this is the Long Night Moon. The plane of the Moon’s orbit around the Earth nearly matches the plane of the Earth’s orbit around the Sun. When the path of the Sun appears lowest in the sky for the year, the path of the full Moon opposite the Sun appears near its highest. For the Washington, DC, area, on Tuesday evening into Wednesday morning, December 7 to 8, 2023, the Moon will be in the sky for a total of 15 hours 57 minutes, with 14 hours 33 minutes of this when the Sun is down, making this the longest full Moon night of the year. The Moon will reach a maximum altitude of 79.0 degrees at 24 minutes after midnight.

As the full Moon after the winter solstice, some consider this the Moon after Yule. Yule was a 3- to 12-day festival near the winter solstice in pre-Christian Europe. In the tenth century King Haakon I associated Yule with Christmas as part of the Christianization of Norway, and this association spread throughout Europe. However, when Yule was celebrated is unclear. Some sources associate it with the 12 days of Christmas, which puts the Moon after Yule in January. Other sources suggest that Yule is an old name for the month of January, so the Moon after Yule is in February. In the absence of better information, I’m going with the full Moon after the winter solstice as the Moon after Yule.

This full Moon corresponds with Datta Jayanti, also known as Dattatreya Jayanti, a Hindu festival commemorating the birth day of the Hindu god Dattatreya (Datta). This full Moon corresponds with the Thiruvathira festival celebrated by Hindus in the Indian states of Kerala and Tamil Nadu.

For the Buddhists of Sri Lanka, this is Unduvap Poya. In the third century BCE, Sanghamitta Theri, the daughter of Emperor Asoka of India and founder of an order of Buddhist nuns in Sri Lanka, brought a branch of the Bodhi Tree to Sri Lanka. This sapling was planted in 288 BCE by King Devanampiya Tissa in the Mahamevnāwa Park in Anuradhapura, Sri Lanka, where it still grows today, making it the oldest living human-planted tree with a known planting date.

We could also call this the Chang’e Moon, after the three Chinese lunar landers that launched and landed on the Moon this time of year. These missions get their name from the Chinese goddess of the Moon, Chang’e, who lived on the Moon with her pet rabbit, Yutu. The Chang’e 3 lander and its companion Yutu-1 rover launched on December 1 and landed on the Moon on December 14, 2013. The Chang’e 4 lander and Yutu-2 rover launched December 7, 2018, and landed on the Moon on January 3, 2019. The Chang’e 5 lunar sample return mission launched on November 23 (in UTC, November 24 in China’s time zone), collected samples from the Moon, and returned them to Earth on December 16, 2020, humanity’s first lunar sample return since 1976.

In many lunar and lunisolar calendars the months change with the new Moon and full Moons fall in the middle of the lunar month. This full Moon is in the middle of the eleventh month of the Chinese calendar, Tevet in the Hebrew calendar, and Jumada al-Thani in the Islamic calendar, also known as Jumada al-Akhirah or Jumada al-Akhir.

As usual, the wearing of suitably celebratory celestial attire is encouraged in honor of the full Moon. Make sure you are ready for winter and take advantage of these early sunsets to enjoy and share the wonders of the night sky.

As for other celestial events between now and the full Moon after next (with times and angles based on the location of NASA Headquarters in Washington, DC):

As winter continues, the daily periods of sunlight continue lengthening. On Tuesday, December 26, 2023 (the day of the full Moon), morning twilight will begin at 6:22 AM, sunrise will be at 7:25 AM, solar noon will be at 12:09 PM when the Sun will reach its maximum altitude of 27.8 degrees, sunset will be at 4:52 PM, and evening twilight will end at 5:56 PM. Our 24-hour clock is based on the average length of the solar day. Although the day of the winter solstice is sometimes called the “shortest day of the year” (because it has the shortest period of sunlight), the solar days near the solstice are actually the longest solar days of the year. Because of this, the earliest sunset of the year occurs before the solstice and the latest sunrise of the year (ignoring Daylight Savings Time) occurs after the solstice. For the Washington, DC area and similar latitudes (I’ve not checked other latitudes), Friday, January 5, 2024, will have the latest (non-daylight-savings time) sunrise of the year (with sunrise at 7:26:56 AM EST). By Thursday, January 25 (the day of the full Moon after next), morning twilight will begin at 6:24 AM, sunrise will be at 7:27 AM, solar noon will be at 12:13 PM when the Sun will reach its maximum altitude of 28.5 degrees, sunset will be at 5:00 PM, and evening twilight will end at 6:03 PM.

The Quadrantids (010 QUA) meteor shower is predicted to be active from December 28, 2023 to January 12, 2024, peaking early Thursday morning, January 4. This shower can have visible meteor rates as high as the other two reliably rich meteor showers (the Perseids in August and the Geminids in December), but is harder to see because the peak is narrower (only a few hours) and these meteors are fainter. The best time to look may be the morning of January 4 for the hour or two before the Moon rises (at 2:29 AM EST), as moonlight will interfere at the time of the predicted peak at 4 AM EST. The International Meteor Organization (IMO) reports that video and radio forward scatter data from the last few years suggest the peak may be a few hours ahead of the predicted peak and that the maximum may be wider than the usually quoted 4 hours, making the time before moonrise more promising.

The area of the sky that these meteors will appear to radiate out from (called the radiant) will rise above the north-northeastern horizon Wednesday night at around 10 PM EST. The higher the radiant is above the horizon the fewer meteors will be hidden, so it’s generally best to look after midnight but before moonrise. To see these meteors you will need a dark place far from the glow of city lights with a clear view of a large part of the sky, and for the weather to cooperate by providing a clear sky without clouds or haze. This is particularly important because these meteors tend to be faint.

Be sure to give your eyes plenty of time to adapt to the dark. The rod cells in your eyes are more sensitive to low light levels but play little role in color vision. Your color-sensing cone cells are concentrated near the center of your view with more rod cells on the edge of your view. Since some meteors are faint, you will tend to see more meteors from the “corner of your eye” (which is why you need to view a large part of the sky). Your color vision (cone cells) will adapt to darkness in about 10 minutes, but your more sensitive night vision rod cells will continue to improve for an hour or more (with most of the improvement in the first 35 to 45 minutes). The more sensitive your eyes are, the more chance you have of seeing meteors. Even a short exposure to light (from passing car headlights, etc.) will start the adaptation over again (so no turning on a light or your cell phone to check what time it is).

These meteors are caused by a stream of debris that enters the Earth’s atmosphere at 41 kilometers per second (92,000 miles per hour). The source of this debris might be the asteroid (196256) 2003 EH1, which may be an extinct comet and may be related to a comet discovered by Chinese, Japanese, and Korean astronomers in 1490 (called C/1490 Y1).

Despite the cold weather, these still should be great evenings for Jupiter and Saturn watching, especially with a backyard telescope. Both will appear to shift westward each night. Jupiter was at its closest and brightest on November 2, 2023, and will be high in the sky as evening twilight ends. Saturn was at its closest and brightest for the year on August 27, and will be lower in the sky, gradually shifting towards the west-southwestern horizon. With clear skies and a telescope you should be able to see Jupiter’s four bright moons, Ganymede, Callisto, Europa, and Io, noticeably shifting positions in the course of an evening. For Saturn, you should be able to see Saturn’s rings as well as Saturn’s largest moon, Titan.

On the evening of Tuesday, December 26 (the evening of the night of the full Moon), as evening twilight ends (at 5:56 PM EST), the rising Moon will be 15 degrees above the east-northeastern horizon. Two planets will be visible. The brightest will be Jupiter at 51 degrees above the southeastern horizon. Saturn will be 33 degrees above the south-southwestern horizon. The bright object appearing closest to overhead will be the star Deneb at 52 degrees above the west-northwestern horizon, with Jupiter a close second. Deneb is the brightest star in the constellation Cygnus the swan and is one of the three bright stars of the “Summer Triangle” (along with Vega and Altair). Deneb is about 20 times more massive than our Sun and has used up its hydrogen, becoming a blue-white supergiant about 200 times the diameter of the Sun. If Deneb were where our Sun is, it would extend to about the orbit of the Earth. Deneb is about 2,600 light years from us and is the 19th brightest star in our night sky.

As this lunar cycle progresses, Jupiter, Saturn, and the background of stars will appear to shift westward each evening (as the Earth moves around the Sun). The still full Moon will appear near the bright star Pollux on December 27 and the waxing Moon will pass by Saturn on January 14, 2024, Jupiter on January 18, the Pleiades star cluster on January 20, and Pollux on January 24.

By the evening of Thursday, January 25 (the evening of the day of the full Moon after next), as evening twilight ends (at 6:22 PM EST), the rising Moon will be 11 degrees above the east-northeastern horizon. Two planets will be visible. The brightest will be Jupiter at 64 degrees above the southern horizon, making Jupiter the bright object closest to overhead. Saturn will be 15 degrees above the west-southwestern horizon.

On the morning of Wednesday, December 27, 2023 (the morning of the night of the full Moon), as morning twilight begins (at 6:22 AM EST), the setting full Moon will be 18 degrees above the west-northwestern horizon. The only visible planet will be bright Venus at 19 degrees above the southeastern horizon. The bright object appearing closest to overhead will be the star Arcturus at 61 degrees above the southeastern horizon. Arcturus is the brightest star in the constellation Boötes the herdsman or plowman, is the 4th brightest star in our night sky, and is 36.7 light years from us. While it has about the same mass as our Sun, it is about 2.6 billion years older and has used up its core hydrogen, becoming a red giant 25 times the size and 170 times the brightness of our Sun.

As this lunar cycle progresses, the background of stars will appear to shift westward each evening, while Venus will gradually shift the other direction towards the southeastern horizon. After December 28 the planet Mercury will join Venus in the morning sky, rising on the east-southeastern horizon before morning twilight begins. Mercury will reach its highest as morning twilight begins on January 8, 2024, after which it will shift towards the horizon again. After January 20 the planet Mars will join Venus and Mercury, rising on the east-southeastern horizon before morning twilight begins. The waning Moon will pass near Pollux on December 28, Regulus on December 31, Spica on January 4 and 5, Antares and bright Venus on January 8 (with Mercury farther to the left), and Mercury on January 9. One of the three major meteor showers of the year, the Quadrantids, is predicted to peak early January 4. The best time to look may be the hour or two before the Moon rises (at 2:29 AM EST), as moonlight will interfere by the time of the predicted peak at 4 AM.

By the morning of Thursday, January 25 (the morning of the day of the full Moon after next), as morning twilight begins (at 6:19 AM EST), the setting full Moon will be 13 degrees above the west-northwestern horizon. Three planets will be visible in the sky (although two will be very low on the horizon). The brightest will be Venus at 10 degrees above the southeastern horizon. Next in brightness will be Mercury at 1.5 degrees above the east-southeastern horizon. To the lower left of Mercury will be Mars, just barely above the horizon. Mercury and Mars will appear at their closest to each other two mornings later. The bright object appearing closest to overhead will still be the star Arcturus at 70 degrees above the southern horizon.

Here for your reference is a day-by-day listing of celestial events between now and the full Moon after next. The times and angles are based on the location of NASA Headquarters in Washington, DC, and some of these details may differ for where you are (I use parentheses to indicate times specific to the DC area).

Thursday evening, December 21, 2023, at 10:27 PM EST, will be the winter solstice. This will be the day with the shortest period of daylight (9 hours, 26 minutes, 13 seconds long). Worldwide there are many festivals associated with the winter solstice, including Yule and the Chinese Dongzhi Festival.

Europeans have used two main ways to divide the year into seasons and define winter. The old Celtic calendar used in much of pre-Christian Europe considered winter to be the quarter of the year with the shortest periods of daylight and the longest periods of night, so that winter started around Halloween and ended around Groundhog Day (hence the origin of these traditions). However, since it takes time for our planet to cool off, the quarter year with the coldest average temperatures starts later than the quarter year with the shortest days. In our modern calendar we approximate this by having winter start on the winter solstice and end on the spring equinox. For the Washington, DC area at least, the quarter year with the coldest average temperatures actually starts the first week of December and ends the first week of March.

Solar noon on Thursday, December 21, to solar noon on Friday, December 22, 2023, will be the longest solar day of the year, 24 hours 29.8 seconds long. In this sense, the “shortest day of the year” is also the “longest day of the year!”

Thursday night into Friday morning, December 21 to 22, 2023, the bright planet Jupiter will appear near the waxing gibbous Moon. Jupiter will be 8 degrees to the lower left of the Moon as evening twilight ends (at 5:53 PM EST). The Moon will reach its highest in the sky for the night 2 hours later (at 7:53 PM) with Jupiter 7 degrees to the left. By the time the Moon sets on the west-northwestern horizon (at 2:50 AM) Jupiter will be 4 degrees to the upper left of the Moon.

Friday afternoon, December 22, 2023, the planet Mercury will be passing between the Earth and the Sun as seen from the Earth, called inferior conjunction. Planets that orbit inside of the orbit of Earth can have two types of conjunctions with the Sun, inferior (when passing between the Earth and the Sun) and superior (when passing on the far side of the Sun as seen from Earth). Mercury will be shifting from the evening sky to the morning sky and will begin emerging from the glow of dawn on the east-southeastern horizon in late December (depending upon viewing conditions).

Friday evening, December 22, 2023, the waxing gibbous Moon will have shifted to the other side of the bright planet Jupiter, with Jupiter appearing 6.5 degrees to the upper right of the Moon. Jupiter will appear to shift clockwise around the Moon, moving farther away as the night progresses.

Saturday evening into Sunday morning, December 23 to 24, 2023, the Pleiades star cluster will appear near the waxing gibbous Moon. The Pleiades will be about 6 degrees to the lower left as evening twilight ends (at 5:54 PM EST) and will shift clockwise around the Moon, appearing about 4 degrees to the upper left by the time the Moon reaches its highest in the sky (at 9:34 PM). By the time the Moon sets on the west-northwestern horizon (at 5:11 AM) the Pleiades will be less than 2 degrees to the upper right of the Moon. Due to the glare of the nearly full Moon, it may be difficult to see the Pleiades without very clear and dark skies or binoculars.

As mentioned above, the next full Moon will be Tuesday evening, December 26, 2023, at 7:33 PM EST. This will be on Wednesday in Coordinated Universal Time (UTC) and for most of Eurasia, Africa, and Australia. Many commercial calendars use UTC and will show this full Moon on Wednesday. The Moon will appear full for 3 days, from Monday evening to Thursday morning.

Wednesday evening into Thursday morning, December 27 to 28, 2023, the bright star Pollux will appear near the still full Moon. As evening twilight ends (at 5:56 PM EST) Pollux will be 6.5 degrees to the lower left of the Moon low on the east-northeastern horizon. By the time the Moon reaches its highest in the sky for the night 7 hours later (at 1:15 AM) Pollux will be 3 degrees to the upper left. As morning twilight begins (at 6:22 AM) Pollux will be 2.5 degrees to the upper right of the Moon.

Thursday morning, December 28, 2023, will be the first morning the planet Mercury will be above the east-southeastern horizon as morning twilight begins (at 6:22 AM EST).

Thursday night, December 28, 2023, the waning gibbous Moon will have shifted to the other side of the bright star Pollux. As the Moon rises (at 6:22 PM EST) above the east-northeastern horizon 25 minutes after evening twilight ends, Pollux will be 7 degrees to the upper right of the Moon, and the pair will separate as the night progresses.

Saturday night into Sunday morning, December 30 to 31, 2023, the bright star Regulus will appear near the waning gibbous Moon. As Regulus rises above the east-northeastern horizon (at 8:59 PM EST) it will be 5.5 degrees to the lower right of the Moon. By the time the Moon reaches its highest in the sky for the night (at 3:38 AM) Regulus will be 3.5 degrees below the Moon. As morning twilight begins (at 6:23 AM) Regulus will be 3 degrees to the lower left of the Moon.

Monday morning, January 1, 2024, at 10:29 AM EST, the Moon will be at apogee, its farthest from the Earth for this orbit.

Tuesday evening, January 2, 2024, the Earth will be at perihelion, the closest we get to the Sun in our orbit. Between perihelion and 6 months later at aphelion there is about a 6.7% difference in the intensity of the sunlight reaching the Earth, one of the reasons the seasons in the Southern hemisphere are more extreme than in the Northern Hemisphere. Perihelion is also when the Earth is moving the fastest in its orbit around the Sun, so if you run east at local midnight, you will be moving about as fast as you can (at least in Sun-centered coordinates) for your location. Wednesday evening, January 3, 2024, the waning Moon will appear half-full as it reaches its last quarter at 10:31 PM EST.

The Quadrantids (010 QUA) meteor shower is predicted to peak early Thursday morning, January 4, 2024. The best time to look may be the hour or two before the Moon rises (at 2:29 AM EST). See the meteor shower summary above for more information.

Friday morning, January 5, 2024, the bright star Spica will appear to the upper right of the waning crescent Moon. As the Moon rises on the east-southeastern horizon (at 1:25 AM EST) Spica will be 4 degrees to the upper right. By the time morning twilight begins (at 6:24 AM) Spica will be 5.5 degrees to the upper right.

Ignoring Daylight Savings Time, for the Washington, DC area and similar latitudes, (I’ve not checked elsewhere), Friday, January 5, 2024, will be the morning with the latest sunrise of the year, 7:26:56 AM EST.

Sunday morning, January 7, 2024, as morning twilight begins (at 6:24 AM EST), the waning crescent Moon will be 22 degrees above the south-southeastern horizon, with the bright planet Venus to the lower left at 15 degrees above the southeastern horizon, the bright star Antares to the lower right of Venus at 11 degrees above the horizon, and the planet Mercury farther to the lower left of Venus at 5 degrees above the east-southeastern horizon. The planet Mars will join this lineup 8 minutes later, rising in the glow of dawn to the lower left of Mercury.

Monday morning, January 8, 2024, the Moon, Venus, and Antares will appear clustered together above the southeastern horizon, with Mercury farther to the lower left. As morning twilight begins (at 6:24 AM EST) the bright planet Venus will appear 7 degrees to the upper left of the waning crescent Moon with the bright star Antares 1.5 degrees to the lower left of the Moon. The planet Mercury will be farther to the lower left of the Moon, Venus, and Antares, this being the morning when Mercury will be at its highest as twilight begins, a little over 6 degrees above the east-southeastern horizon. Mars will rise 7 minutes later, joining this grouping.

By Tuesday morning, January 9, 2024, the Moon will have shifted to 8 degrees to the lower right of Mercury, appearing only 3 degrees above the southeastern horizon as morning twilight begins (at 6:24 AM EST). The Moon will be a thin crescent and may be hard to see. Mars will rise in the glow of dawn 7 minutes later to the lower left of Mercury.

Thursday morning, January 11, 2024, at 6:57 AM EST, will be the new Moon, when the Moon passes between the Earth and the Sun and will not be visible from the Earth. The day of or the day after the New Moon usually marks the start of the new month for most lunisolar calendars. Sundown on Wednesday, January 10, marks the start of Shevat in the Hebrew calendar. The twelfth month of the Chinese year of the Rabbit starts on January 11.

Friday morning, January 12, 2024, will be when the planet Mercury reaches its greatest angular separation from the Sun as seen from the Earth for this apparition (called greatest elongation). Because the angle of the line between the Sun and Mercury and the horizon changes, when Mercury and the Sun appear farthest apart as seen from the Earth is not always when Mercury appears highest above the east-southeastern horizon as morning twilight begins, which occurred January 8.

In the Islamic calendar the months traditionally start with the first sighting of the waxing crescent Moon. Many Muslim communities now follow the Umm al-Qura Calendar of Saudi Arabia, which uses astronomical calculations to start months in a more predictable way. Using this calendar, sundown on Friday evening, January 12, 2024, will probably mark the beginning of Rajab, the seventh month of the Islamic calendar. Rajab is one of the four sacred months in which warfare and fighting are forbidden.

Saturday morning, January 13, 2024, at 5:36 AM EST, the Moon will be at perigee, its closest to the Earth for this orbit.

Sunday evening, January 14, 2024, the planet Saturn will appear to the lower right of the waxing crescent Moon. The pair will be 7 degrees apart as evening twilight ends (at 6:11 PM EST) and Saturn will set first on the west-southwestern horizon a little over 2 hours later (at 8:26 PM).

Wednesday evening, January 17, 2024, the Moon will appear half-full as it reaches its first quarter at 10:53 PM EST.

Thursday evening into early Friday morning, January 18 to 19, 2024, the bright planet Jupiter will appear below the waxing gibbous Moon. Jupiter will be 3 degrees to the lower right of the Moon as evening twilight ends (at 6:15 PM EST) and will be 6 degrees below the Moon by the time Jupiter sets on the west-northwestern horizon 7 hours later (at 1:17 AM).

Saturday morning, January 20, 2024, will be the first morning that the planet Mars will be above the east-southeastern horizon as morning twilight begins (at 6:22 AM EST).

Saturday evening into Sunday morning, January 20 to 21, 2024, the Pleiades star cluster will appear near the waxing gibbous Moon. The Pleiades will be 5 degrees to the upper right of the Moon as evening twilight ends (at 6:17 PM EST). The Moon will reach its highest for the night 2 hours later (at 8:23 PM) with the Pleiades 6 degrees to the right. By the time the Pleiades set on the west-northwestern horizon (at around 3:25 AM) they will be 9 degrees to the lower right of the Moon.

Late Tuesday night into Wednesday morning, January 23 to 24, 2024, the bright star Pollux will appear near the nearly full Moon. As evening twilight ends (at 6:20 PM EST) Jupiter will be 10 degrees to the lower left of the Moon, but will shift closer as it swings clockwise around the Moon. When the Moon reaches its highest for the night 5 hours later (at 11:08 PM) Jupiter will be 8 degrees to the left of the Moon. By the time morning twilight begins (at 6:20 AM) Jupiter will be 5 degrees above the Moon.

Thursday night into Friday morning, January 24 to 25, 2024, the Moon will have shifted to the other side of the bright star Pollux. Pollux will appear 3.5 degrees above the Moon as evening twilight ends (at 6:21 PM EST) and will appear to swing clockwise around the Moon as they move apart. When the Moon reaches its highest for the night (at midnight) Pollux will be 5.5 degrees to the upper right. As morning twilight begins (at 6:19 AM) Pollux will be 8 degrees to the lower right of the Moon.

The full Moon after next will be Thursday afternoon, January 25, 2024, at 12:54 PM EST. This will be on Friday morning from Myanmar time eastward to the International Dateline in the mid-Pacific. The Moon will appear full for about 3 days around this time, from around midnight Wednesday morning through about midnight Friday night.