With the advent of Winter SolsticeThe Northern Hemisphere bids farewell to autumn and welcomes the coldest season of the year. It's the time when we enjoy the Shortest day and longest night, an astronomical milestone that marks the calendar every December and that in Spain is accompanied by a good handful of interesting celestial phenomena.
Although many people associate winter only with low temperatures and blankets on the sofa, behind the solstice there is a a very precise astronomical explanation and enormous cultural symbolismFrom the position of the Sun over the Tropic of Capricorn to meteor showersWith prominent constellations and introspective rituals, this period offers much more than meets the eye.
What exactly is the winter solstice?
The term solstice comes from Latin solstitium, "sun standing still"It is called this because, for several days around that date, the maximum height of the Sun at midday hardly varies, giving the impression that the star remains "stopped" in the sky before starting its journey north again.
This moment occurs when the Earth, due to the effect of the tilt of its axis of rotation (about 23,4 degrees) With respect to its orbit around the Sun, it places the northern hemisphere farther from direct solar radiation. The result is easy to notice: fewer hours of daylight and more hours of darkness in our latitudes, while in the southern hemisphere the opposite happens and summer begins.
During the winter solstice, the Sun traces a path in the sky shortest bow of the yearIts elevation at midday is the lowest seen from Europe, and yet that same geometry is what causes the days to gradually lengthen from that day onwards, something that many cultures have interpreted as the progressive return of light.
When does astronomical winter begin and how long does it last?
In Spain and the rest of Europe, the astronomical winter It begins when the Earth passes through the point in its orbit where the The sun reaches its maximum declination to the southThat moment, which does not always fall on the same day or at the same time, defines the official beginning of the winter season in the northern hemisphere.
The start of winter can occur between December 20 and 23However, throughout the 21st century, according to calculations by the National Astronomical Observatory, it is practically limited to the 20th, 21st, or 22nd (in official Spanish time). These variations are due to how they fit leap years and the actual duration of Earth's orbit with the civil calendar we use.
In mainland Spain and the Balearic Islands, the exact time is usually communicated with minute precision: for example, the start of winter can be set at 16:03 Peninsular Time (15:03 in the Canary Islands), coinciding with the solstice. From that moment, the last season of the year begins, lasting... about 88 days and 23 hours until the arrival of spring, around March 20th.
Winter is, in fact, the shortest season of the year in the northern hemisphereThe reason is that Earth's orbit is elliptical, and winter coincides with the period when the planet is closest to the Sun. According to Kepler's second law, when Earth is in this closest approach, it shifts faster around its orbitTherefore, it takes less time to complete the winter section than the section for other seasons.
The shortest day and the longest night in Spain
The winter solstice marks the day with fewer hours of sunlight per year in our latitudes. However, the exact length of day and night varies greatly depending on the location. Experiencing the solstice in Madrid is not the same as in a city near the equator or at a more northerly latitude.
Taking the peninsular center as a reference, for the latitude of Madrid On the day of the solstice, the Sun is above the horizon about 9 17 hours and minuteswhile the night stretches on until 14 43 hours and minutesCompared to the summer solstice, when there were approximately 15 hours and 3 minutes of daylight, the difference between the shortest and longest day of the year is around six hours of sun.
The closer we get to the equator, the more the difference between winter and summer decreases; in contrast, it is extreme in the polar regions. North PoleFor example, the night that began with the autumn equinox reaches its midpoint at the winter solstice, and there are still about three more months of continuous darkness before the light returns with spring.
Around December 21st, in regions such as Antarctica The phenomenon known as the "Midnight Sun" can be observed, in which the star remains visible 24 hours a day above the horizon, the exact opposite of the northern winter.
The Sun over the Tropic of Capricorn and the Earth near perihelion
From a geometric point of view, the winter solstice is characterized by the fact that The sun is located at midday over the Tropic of Capricorn, at its southernmost position as seen from Earth. For an observer in Europe, this configuration makes the star appear very low on the horizon during the middle of the day.
In the days before and after the solstice, the maximum altitude of the Sun changes so little that it seems barely "still" in the skyThis gave rise to the name solstitium, or "stationary sun." After this brief period, the sun begins to gradually gain altitude each day, extending the available daylight hours.
It may seem shocking, but the coldest season in the Northern Hemisphere coincides with the time when the Earth is closer to the Sun in its elliptical orbitThat point is called perihelion and is reached around the January 3, when the distance between our planet and the star is around 147 million kilometers, about 5 million less than at the aphelion in July, when it is farthest away.
The fact that in the middle of winter we are closer to the Sun and yet it is colder is explained by the fact that climate is not determined solely by distance from the star, but also the tilt of the Earth's axis and the angle at which the sun's rays arriveIn Europe, these rays strike at a very oblique angle at this time of year, distributing the energy over a larger surface and heating less.
The winter astronomical calendar: meteor showers, full moons and eclipses
Winter in Spain and the rest of Europe is accompanied by long, cold, and usually dry nightsThese conditions are usually favorable for stargazing, weather permitting. During these months, several significant astronomical phenomena can be observed, some visible to the naked eye.
Among the most prominent events are the meteor showers. On the one hand, the Ursidswhose activity extends approximately from December 16 to 26, reach their peak around December 22They originate when Earth crosses a region of its orbit where dust, ice, and small fragments from comet 8P/Tuttle, about 4,5 kilometers in diameter, accumulate. Their meteor rate is usually modest, between 10 and 50 flashes per hour, with speeds close to 33 kilometers per second.
At the beginning of January it's the turn of the quadrantidsThe most intense meteor shower of winter. Its peak occurs on the night of January 3 to 4Depending on the lunar phase of each year, the observation may be more or less affected by the brightness of the Moon, but, even so, it is considered one of the most interesting rains of the season for those who dare to go out warmly dressed into the countryside.
As for our satellite, several events occur during the winter full moons These meteor showers occur between early January, early February, and the first days of March. These dates offer good opportunities for night photography of snowy landscapes or illuminated cityscapes, although moonlight reduces contrast for viewing other, fainter meteor showers.
The winter term may also include two eclipsesOne annular solar eclipse and one total lunar eclipse. The annular solar eclipse occurs around the February 17 and is only visible from regions such as Antarctica, the Southern Ocean and the southern Indian Ocean, or parts of southern Africa or South America, depending on the year. The next total lunar eclipse, expected around 3 MarchIt can be observed from areas such as America, East Asia or Oceania, and even Europe at certain times, but It is not always visible from Spain because the Moon may already be below the horizon.
Planets and constellations visible in the cold months
Beyond meteor showers and eclipses, the winter sky offers a showcase of easily recognizable planets and constellationsDuring the first few weeks of the season, planets such as [names of planets] can be seen at dawn. Jupiter and Mercuryalthough the latter tends to disappear soon in the sunlight and reappear again around March.
As evening falls, the focus shifts to the western and southern skies, where they become visible Saturn, Jupiter, and, from a certain point on, VenusAs the weeks go by, Saturn gets closer to the Sun and disappears from view in early March, while Mercury begins to stand out in the sunsets of February, although always very low and fleeting above the horizon.
The winter night sky in the northern hemisphere is also famous for hosting some of the brightest constellationsAmong the fan favorites are Orion, with the variable Betelgeuse; Taurus, with the reddish Aldebaran; Canis Majorwhich is home to Sirius (the brightest star in the night sky); and Gemini, with the star pair Castor and Pollux.
Several of these stars, visually linked to other nearby stars, form an asterism known as the winter hexagon, easily recognizable on clear nights and one of the great attractions of the winter sky for those starting out in astronomical observation.
Symbolism, rituals and ways of experiencing the solstice
Beyond the technical data, the winter solstice has been interpreted for centuries as a turning point between darkness and the return of lightFrom that day onwards, the hours of daylight begin to increase, and many cultures have seen this as a metaphor for renewal, hope, and the beginning of new cycles.
Today, it is still common to take advantage of this moment to to connect more consciously with the rhythms of natureIn contrast to time measured by clocks and calendars, the solstices and equinoxes remind us that life is also organized in cycles, with phases of introspection and others of expansion. The winter solstice, in particular, invites us to introspection, rest, and calmly plan the steps we want to take when the light returns.
Many people mark the date with simple gestures but full of intentionActivities include lighting a candle, sharing a special meal, meditating for a few minutes, or writing down resolutions. Typically wintery colors like red, green, gold, or silver are associated with the holiday, and warm, spiced foods are enjoyed: spiced wine or cider, ginger infusions, traditional sweets, or the classic Yule log in some European traditions.
They are also used herbs and symbolic elements such as laurel, mistletoe, thistle, cinnamon or branches of evergreen trees, all of them historically linked to protection, prosperity or the continuity of life in the middle of the cold season.
The solstice in the city: the case of Zaragoza
The link between the winter solstice and urban layout is not limited to ancient megalithic monuments. In Spain, a good modern example of this relationship can be found in Zaragoza, where every December a unique way of experiencing the beginning of winter has become established.
In the city's historic center, several streets replicate the orientation of the old Roman layout of caesaraugustaAt dawn on the days near the solstice, around the 8: 30 in the morningThe sun's rays align with Calle Mayor and other nearby streets, running in a practically straight line from the Magdalena area to the confluence with Don Jaime and continuing along Espoz y Mina and Manifestación.
It is believed that, when the Romans designed the urban layout, they took into account the position of the Sun on key dates such as the solstice, orienting the cardo and decumanus maximus of the colony with the sky as a reference point. With this, they intended that the star would symbolically "fertilize" the territory, marking at the same time the founding and identity of the city.
What for years was almost a curiosity known only to a few has become a small a community event that is attracting more and more people each timewho gather to watch as a ray of sunshine travels along the urban axis as winter is officially inaugurated.
A time to look at the sky and inward.
The winter solstice in Spain and the rest of Europe combines science, tradition, and personal experienceOn the one hand, it accurately marks the beginning of the shortest season of the year, explains why the days are so short, and serves as a reference for eclipses, meteor showers, full moons, and the observation of planets and winter constellations.
On the other hand, it remains a date filled with symbolic meaningDuring this time, many people take the opportunity to pause, reflect on the year, and prepare for a new cycle of increasing light. Amid clear skies, cool nights, and simple rituals, the solstice invites us both to look up at the stars and to set aside a moment of calm to listen to our inner selves.
