January 2021: The Next Full Moon is Another Wolf Moon

The next full Moon will be Thursday afternoon, January 28, 2021, appearing opposite the Sun in Earth-based longitude at 2:16 PM EST. The Moon will appear full for about three days around this time, from Wednesday morning through the early part of Saturday morning.

As the full Moon in January this is known as the Wolf Moon. In the 1930's the Maine Farmer's Almanac began publishing "Indian" Moon names for each month of the year. These names have become popular and widely known. The original source of these names is not completely clear, with some indication they came from the Algonquin language as adapted by colonial Americans. In past Moon Missives I've used these Moon names by where they are in the seasons rather than by month, as I thought it likely to be closer to the original tradition (especially if it predated widespread contact with Europeans). After more reading, I've decided to follow the more widely accepted use of these names by month. Probably neither is completely correct. From what I have learned about traditional names given to full Moons prior to the introduction of modern timekeeping, local leaders would usually decide on the name of the Moon based on conditions at the time. These cultures did not generally need calendars that specify exact dates far in advance. Full Moon names were used to describe and remember what happened in the past and to remind of what was likely to come in the near future. Also, there are many different Native American names for the full Moons.

According to some sources, the Wolf Moon is also an old European name for the second full Moon of winter (the midwinter Moon). Another European name for this full Moon is the Candles Moon, tied to Candlemas on February 2nd.

In the Hindu calendar this full Moon is Shakambhari Purnima, the last day in the 8-day Shakambari Navratri holiday that celebrates the goddess Shakambhari. In the Purnimanta tradition that ends the months on the full Moon day, this full Moon (purnima) is Paush Purnima, the last day of the Hindu month Paush. The day after Paush Purnima is the start of the month Magha, a period of austerity. Bathing in the holy waters of India is an important activity for both Shakambari Navratri and Magha.

The Tamil Hindu community celebrates the Thaipusam festival on this full Moon.

In Myanmar this full Moon corresponds with the Ananda Pagoda Festival, a week-long festival celebrating this Buddhist temple built in 1105 AD in the city of Bagan.

For the Buddhists of Sri Lanka, this is Duruthu Poya, which commemorates Siddhartha Gautama Buddha's first visit to Sri Lanka.

In most 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 the middle of the twelfth month of the Chinese calendar, Shevat in the Hebrew calendar, and Jumada al-Thani in the Islamic calendar, also known as Jumada al-Akhirah or Jumada al-Akhir. In the Hebrew calendar the 15th day of Shevat is the holiday Tu BiShvat. Tu B'Shevat for the year 2021 is observed from sunset of Wednesday, January 27, ending at nightfall on Thursday, January 28. Tu BiShvat is also called "Rosh HaShanah La'Ilanot" (literally "New Year of the Trees"). In contemporary Israel, the day is celebrated as an ecological awareness day, and trees are planted in celebration.

As usual, the wearing of suitably celebratory celestial attire is encouraged in honor of the full Moon. Stay warm, but take advantage of these early nightfalls to get out, look up, and share the wonders of the sky!

Here is a summary of celestial events between now and the full Moon after next (with angles and times based on the location of NASA Headquarters in Washington, DC):

As winter continues in the northern hemisphere, the daily periods of sunlight continue to lengthen. On Thursday, January 28, 2021 (the day of the full Moon), morning twilight will begin at 6:17 AM EST, sunrise will be at 7:17 AM, solar noon will be at 12:21:06 PM when the Sun will reach its maximum altitude of 33.14 degrees, sunset will be at 5:25 PM, and evening twilight will end at 6:26 PM. By Saturday, February 27, 2021 (the day of the full Moon after next), morning twilight will begin at 5:45 AM EST, sunrise will be at 6:43 AM, solar noon will be at 12:20:41 PM when the Sun will reach its maximum altitude of 43.06 degrees, sunset will be at 5:59 PM, and evening twilight will end at 6:57 PM.

On the evening of Thursday, January 28, 2021, (the day of this full Moon), as evening twilight ends (at 6:26 PM EST), the planet Mars will appear about 67 degrees above the horizon in the south-southwest and will be the brightest object appearing close to directly overhead. The planet Mercury will appear about 4 degrees above the horizon in the west-southwest. The bright stars of the Orion–Cygnus Arm of our home galaxy will appear in the southeastern sky.

As the lunar cycle progresses, these planets and the background of stars will appear to shift towards the west. Mars will remain high and visible, having passed its closest and brightest for the year on October 13, 2020. After February 1, 2021, the planet Mercury will be below the horizon at the time evening twilight ends. After February 5 Mercury will have set within 30 minutes of sunset (an approximation of when Mercury will be hidden by the glow of dusk). Mercury will pass between the Earth and the Sun (called inferior conjunction) on the morning of February 8, 2021, shifting from the evening sky to the morning sky.

By the evening of Saturday, February 27, 2021, (the day of the full Moon after next), as evening twilight ends (at 6:57 PM EST), the only planet visible will be Mars, appearing about 62 degrees above the west-southwestern horizon. The bright star appearing closest to directly overhead will be Capella at 83 degrees above the northern horizon. The bright stars of the Orion–Cygnus Arm of our home galaxy, including the easy-to-recognize constellation of Orion, will appear spread from the south-southeast up towards Mars. The three stars of Orion's Belt will appear to point to the lower left towards the bright star Sirius, the brightest of the stars in our sky (other than the Sun).

On the morning of Thursday, January 28, 2021, (the day of this full Moon), as morning twilight begins (at 6:17 AM EST), the bright star appearing closest to overhead will be Arcturus, appearing about 69 degrees above the horizon in the south-southwest. The planet Venus will not rise for another 18 minutes (about 39 minutes before sunrise), making it difficult to see in the glow of dawn as it appears in the east-southeast.

As the lunar cycle progresses, the background of stars will appear to shift towards the west each morning. February 3, 2021, will be the last morning when Venus will appear above the horizon at 30 minutes before sunrise (an approximation of the last time it will appear visible in the glow of dawn for this apparition). After February 15, 2021, the bright planet Jupiter will begin emerging from the glow of dawn, rising in the east-southeast about 30 minutes before sunrise. By February 18, 2021, both the planets Mercury and Saturn will begin appearing above the horizon in the east-southeast at the time morning twilight begins (at 5:57 AM EST), with Saturn appearing to the right of Mercury. Initially Saturn will be the brighter of the two, but after about February 21, 2021, Mercury will appear brighter than Saturn. Mercury and Saturn will appear higher in the sky each morning until February 26, 2021, when Mercury will appear at its highest for this apparition, after which Saturn will continue to shift higher while Mercury will begin to shift back closer to the horizon.

By the morning of Saturday, February 27, 2021, (the day of the full Moon after next), as morning twilight begins (at 5:45 AM EST), the bright star appearing closest to overhead will be Vega, one of the three stars in the Summer Triangle, at about 61 degrees above the horizon in the east-northeast. A close second will be the bright star Arcturus, appearing 59 degrees above the horizon in the west-southwest. The planet Mercury will appear in the east-southeast about 2 degrees above the horizon, with the fainter planet Saturn appearing about 5 degrees to the right and about 4 degrees above the horizon. About 4 minutes later (at 5:49 AM), the planet Jupiter will rise to the lower left of Mercury, shining brighter than both Mercury and Saturn. To see these three planets you will need a very clear view of the horizon in the east-southeast (something that can be difficult to find in our cluttered urban environments).

Here is a more detailed, day-by-day listing of celestial events between now and the full Moon after next (again based on the location of NASA Headquarters in Washington, DC):

Saturday evening, January 23, 2021, will be when the planet Mercury reaches its greatest angular separation from the Sun as seen from the Earth for this apparition (called greatest eastern elongation), appearing half-lit through a large enough telescope. Because the angle of the line between the Sun and Mercury and the line of the horizon changes over time, when Mercury and the Sun appear farthest apart as seen from the Earth is not the same as when Mercury appears highest above the horizon in the west-southwest as evening twilight ends.

On Saturday evening, January 23, 2021, at 9:26 PM EST, the planet Saturn will be passing on the far side of the Sun as seen from the Earth, called conjunction. Saturn will begin emerging from the glow of dawn on the eastern horizon around February 7, 2021 (depending upon viewing conditions).

On Saturday evening into Sunday morning, January 23 to 24, 2021, the bright star Aldebaran will appear below the waxing gibbous Moon. As evening twilight ends (at 6:21 PM EST) Aldebaran will appear about 5 degrees below the Moon. The Moon will reach its highest point for the night at 8:23 PM and Aldebaran will set first in the west-northwest Sunday morning at 3:28 AM.

Sunday evening, January 24, 2021, will be when the planet Mercury will appear at its highest above the horizon (5 degrees) at the time evening twilight ends (at 6:22 PM EST).

Even though they are not usually visible, I include in these Moon missives information about Near Earth Objects (mostly asteroids) that may pass the Earth within 5 lunar distances, because I find it interesting that we have discovered so many. Sometime in the second half of January to early February, 2021 (2021-Jan-25 10:28 UTC with 7 days, 22 hours, 6 minutes uncertainty), Near Earth Object (2018 BA3), between 15 and 33 meters (48 to 107 feet) across, will pass the Earth at between 0.7 and 9.2 lunar distances (nominally 1.5), traveling at 8.08 kilometers per second (18,080 miles per hour).

On Tuesday evening into Wednesday morning, January 26 to 27, 2021, the bright star Pollux will appear near the waxing gibbous Moon. As evening twilight ends (at 6:24 PM EST), Pollux will appear about 9 degrees to the lower left of the Moon. The Moon will reach its highest point for the night at 10:59 PM with Pollux about 8 degrees to the upper left. By the time morning twilight begins Wednesday morning at 6:18 AM, Pollux will appear about 6 degrees above the Moon, with he Moon about 23 minutes from setting in the west-northwest.

As mentioned above, the next full Moon will be on Thursday afternoon, January 28, 2021, appearing opposite the Sun at 2:16 PM EST. The Moon will appear full from Wednesday morning, January 27, through the early part of Saturday morning, January 30, 2021.

On Thursday evening, January 28, 2021, the planet Jupiter will be passing on the far side of the Sun as seen from the Earth, called conjunction. Jupiter will begin emerging from the glow of dawn on the eastern horizon around February 15, 2021 (depending upon viewing conditions).

Friday evening into Saturday morning, January 29 to 30, 2021, the bright star Regulus will appear below the full Moon. The Moon will rise in the east-northeast as evening twilight ends, with Regulus rising about a half-hour later. The Moon will reach its highest in the sky Saturday morning at 1:42 AM EST, and morning twilight will begin around 6:16 AM.

Monday, February 1, 2021, is Imolc, and Tuesday, February 2, is Candlemas or Groundhog's Day. The tradition in some European countries was to leave Christmas decorations up until February 1st, the eve of Candlemas (it was considered bad luck to leave decorations up past Candlemas). We have a tradition in the USA that if the groundhog sees its shadow, winter will end on Groundhog Day. If not, winter will last six weeks more (ending around the time of the spring equinox).

Groundhog Day appears to tie back to European lore about whether or not badgers, wolves, or bears (instead of groundhogs) see their shadows. We currently divide the year into four seasons based upon the solstices and equinoxes, with spring starting on the vernal equinox. This approximates winter as the quarter of the year with the coldest temperatures. Much of pre-Christian northern Europe celebrated "cross-quarter days" halfway between the solstices and equinoxes, dividing the seasons on these days. Using this definition, winter was the quarter of the year with the shortest daily periods of daylight, and spring started on Imbolc in early February (the middle of our winter).

Many believe that our Groundhog Day and Candlemas traditions tie back to these earlier celebrations for the start of spring. It seems plausible to me that it was confusing to have two competing dates for the end of winter. Perhaps it was best to let a natural event such as an animal’s shadow decide which definition to use, rather than arguing with your neighbors for the next six weeks...

Monday evening, February 1, 2021, will be the last evening for this apparition that the planet Mercury will be above the horizon as evening twilight ends.

On Tuesday afternoon, February 2, 2021, at about 4:42 PM EST (2021-Feb-02 21:42 UTC with 4 minutes uncertainty), Near Earth Object (2020 SO), between 8 and 17 meters (25 to 56 feet) across, will pass the Earth at 0.6 lunar distances, traveling at 1.79 kilometers per second (4,000 miles per hour).

Late Tuesday night into Wednesday morning, February 2 to 3, 2021, the bright star Spica will appear to the lower right of the waning gibbous Moon. The Moon will rise in the east at 11:07 PM EST, with Spica rising to the right about 7 minutes later. The Moon will reach its highest in the sky for the night Wednesday morning at 5:01 AM, and morning twilight will begin around 6:12 AM.

Wednesday, February 3, 2021, will be the last morning for this apparition that Venus will appear above the horizon 30 minutes before sunrise (an approximation of the last time it may be visible in the glow of dawn).

Wednesday afternoon, February 3, 2021, at 2:33 PM EST, the Moon will be at perigee, its closest to the Earth for this orbit.

Thursday midday, February 4, 2021, the waning Moon will appear half-full as it reaches its last quarter at 12:37 PM EST.

Sometime in around the first half of February, 2021 (2021-Feb-05 19:10 UTC with 6 days, 21 hours, 14 minutes uncertainty), Near Earth Object (2018 CH2), between 7 and 15 meters (22 to 49 feet) across, will pass the Earth at between 1.3 and 30.2 lunar distances (nominally 14.5), traveling at 9.92 kilometers per second (22,190 miles per hour).

Friday evening, February 5, 2021, will be the last evening for this apparition that the planet Mercury will appear above the horizon 30 minutes after sunset (an approximation of when Mercury may still be visible in the glow of dusk).

On Saturday morning, February 6. 2021, the bright star Antares will appear to the lower right of the waning crescent Moon. The Moon will rise in the east-southeast at 2:41 AM EST, with Antares rising 22 minutes later. Morning twilight will begin around 6:10 AM.

On Monday morning, February 8, 2021, the planet Mercury will be passing between the Earth and the Sun, 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 the Earth). Mercury will be shifting from the evening sky to the morning sky and will begin emerging from the glow of dawn on the eastern horizon after about February 11, 2021 (depending upon viewing conditions).

Thursday afternoon, February 11, 2021, at 2:06 PM 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 marks the start of the new month for most lunisolar calendars.

The first month of the Chinese calendar starts on Friday, February 12, 2021 (at midnight in China's time zone, which is 13 hours ahead of EST), making this Chinese New Year, the start of the year of the Ox! Chinese New Year (and related celebrations throughout much of Asia and in areas with significant Chinese populations) celebrates the end of winter and start of spring. Traditional festivities start on the eve of Chinese New Year (Thursday, February 11, 2021) and continue until the Lantern Festival on the 15th day of the first lunar month (Friday, February 26, 2021).

Sundown on Friday, February 12, 2021, marks the start of Adar in the Hebrew calendar.

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 the seventh month of the year, Rajab will begin at sunset on Wednesday, February 12, 2021. Rajab is one of the four sacred months in which warfare and fighting are forbidden.

Beginning on or after Monday morning, February 15, 2021, the bright planet Jupiter will begin emerging from the glow of dawn, rising in the east-southeast about 30 minutes before sunrise.

Tuesday, February 16, 2021, will be Mardi Gras, also known as Shrove or Fat Tuesday, the traditional carnival on the last night before the 40 days of fasting for Lent. The date of Mardi Gras is loosely tied to the lunar cycle. Mardi Gras is 47 days before Easter, and Easter is generally tied to the first Sunday after the first full Moon of spring.

On Wednesday evening, February 17, 2021, sometime around 8:29 PM EST (2021-Feb-18 01:29 UTC with 1 hour, 45 minutes uncertainty), Near Earth Object (2020 CX1), between 40 and 90 meters (132 to 295 feet) across, will pass the Earth at between 3.7 and 5.9 lunar distances (nominally 4.8), traveling at 8.27 kilometers per second (18,510 miles per hour).

Thursday morning, February 18, 2021, at 5:22 AM EST, the Moon will be at apogee, its farthest from the Earth for this orbit.

Beginning Thursday morning, February 18, 2021, both the planets Mercury and Saturn will begin appearing above the horizon in the east-southeast at the time morning twilight begins (at 5:57 AM EST), with Saturn appearing to the right of Mercury. Initially Saturn will be the brighter of the two, but after a few mornings Mercury will appear brighter than Saturn.

On Thursday evening, February 18, 2021, the planet Mars will appear to the upper right of the waxing crescent Moon. The Moon will appear 61 degrees above the southwestern horizon as evening twilight ends at 6:48 PM EST, and the Moon and Mars will set together in the west-northwest on Friday morning at 12:40 AM.

On Friday afternoon, February 19, 2021, the Moon will appear half-full as it reaches its first quarter at 1:47 PM EST.

Friday evening into early Saturday morning, February 19 to 20, 2021, the bright star Aldebaran will appear near the half-lit Moon. Aldebaran will appear about 8 degrees to the left of the Moon as evening twilight ends (at 6:49 PM EST), and will appear to shift a degree or so closer by the time the Moon sets Saturday morning (at 1:39 AM). By Saturday evening the Moon will appear to have shifted to about 8 degrees the other side of the Moon, and the pair will continue to separate after that.

After about Sunday morning, February 21, 2021, Mercury will begin appearing brighter than Saturn (I have two sets of brightness predictions that differ by a day or two).

Tuesday morning, February 23, 2021, will be when Mercury and Saturn will appear at their closest together, just 4 degrees apart, low on the east-southeastern horizon (only 2 degrees above the horizon at the time morning twilight begins). After this, Mercury and Saturn will appear to separate, with Saturn continuing higher each morning while Mercury will appear to slow down, then begin to shift back towards the horizon each morning.

Tuesday evening into Wednesday morning, February 23 to 24, 2021, the bright star Pollux, one of the twins in the constellation Gemini, will appear near the waxing gibbous Moon. Pollux will appear about 4 degrees to the upper left of the Moon as evening twilight ends (at 6:53 PM EST). The Moon will reach its highest in the sky for the night (at 9:40 PM) with Pollux appearing about 5 degrees above the Moon, and the Moon will set Wednesday morning (at 5:19 AM) with Pollux about 6 degrees to the right of the Moon.

Friday morning, the bright star Regulus will appear to the left of the full Moon. They will appear more than 8 degrees apart around midnight, but will shift closer together, appearing about 6 degrees apart as morning twilight begins (at 5:47 AM EST).

On Friday morning, February 26, 2021, the planet Mercury will appear at its highest above the horizon for this apparition at the time morning twilight begins, after which it will begin to shift back towards the horizon.

Friday evening, February 26, 2021, the full Moon will appear to the left of the bright star Regulus. As evening twilight ends (at 6:56 PM EST), Regulus will appear about 7 degrees to the upper right of the full Moon, and the pair will appear to separate at the evening progresses.

The full Moon after next will be early Saturday morning, February 27, 2021, at 3:17 AM EST. Because this is near midnight, many of the traditional holidays and festivals associated with this full Moon start the day before, on February 26 (and I will write more about these in next month's Moon Missive). The Moon will appear full for about three days around this time, from Thursday evening, February 25, through Sunday morning, February 28, 2021.