December has established itself as one of the best times of the year to closely follow the December meteor showers From Spain and the rest of Europe. Between long nights, low temperatures and a sky that, with some luck, remains clear, the astronomical calendar offers several key moments for those who enjoy looking up and counting shooting stars.
Within this celestial menu, the main protagonist is the Geminid meteor showerThe Perseid meteor shower, considered by many astronomers to be the most powerful shower of the year in the Northern Hemisphere, surrounds it. Ursids They complete the picture in the final stretch of December, painting a picture of a month in which it is worth preparing warm clothes, choosing a good dark place and reserving several early mornings to enjoy the sky.
What meteor showers can be seen in December
When talking about December meteor showers It doesn't refer to a single phenomenon, but to several meteor showers that overlap throughout the month. Some have already reached their peak activity, others are very weak or unfavorable for the Northern Hemisphere, and a couple of them become real highlights for the general public.
In the outlook for this end of the year, the most noteworthy are the Geminids and the UrsidsOther rains, such as Leonidas or PhoenicidesThey arrive very close to the end of the month or are poorly observed from latitudes such as the Iberian Peninsula or the Balearic Islands, so they are relegated to a secondary role for those who want to focus their outings on the best shows.
In the first part of December, remnants of some minor showers may still be visible, but the most interesting meteor showers are concentrated in the middle and end of the month. This period also coincides with Especially long nights in Spain and Europe due to the proximity of the winter solstice, which leaves many hours of darkness to try to observe shooting stars.
It is important to keep in mind that the The Moon and Light Pollution These factors clearly determine how many meteors can be seen. Although theoretical rates suggest hundreds of meteors per hour, the actual number perceived by the human eye, especially near cities, is usually significantly lower.
The Geminids: December's great meteor shower
Among all December meteor showersThe Geminids almost always grab the headlines. It's a very regular and abundant meteor shower, visible every year. in the first half of December from much of the northern hemisphere, including the Iberian Peninsula, the Balearic Islands and the Canary Islands.
The Geminids originate when the Earth passes through the cloud of fragments of the asteroid 3200 Phaethon (or Phaethon), an ancient, depleted comet that no longer possesses the classic volatile materials. As our planet crosses that region of space, the small rocky fragments come into contact with the atmosphere and They heat up due to friction until they disintegrateproducing the flashes we see as shooting stars.
The name of this rain comes from the constellation geminiwhere the so-called "radiant" is located, that is, the point in the sky from which meteors appear to originate. More specifically, the radiant is located near the Castor star, one of the most prominent features of the winter sky.
Under ideal conditions, under very dark skies and with the radiant high, the Geminids can offer rates of more than 120 meteors per hourand even slightly higher figures. The speed is around 35 kilometers per second., relatively moderate compared to other rains, which results in well-defined strokes and, sometimes, soft colors.
When to see the Geminids from Spain and Europe
The Geminid meteor shower activity period extends approximately from the beginning until around December 20thwith a particularly active period in the second week of the month. However, most sources place the Peak rainfall on the night of December 13-14which is when the most meteors can be observed.
In Spain, astronomical organizations indicate that the maximum usually occurs in the central hours of the early morning of the 14thThis means that, during the night of the 13th to the 14th, good viewing conditions can be obtained both before and after midnight, provided the weather cooperates and the sky is as clear as possible.
From Western Europe, including the Iberian Peninsula, the radiant of the Geminids It begins to gain altitude from late afternoon/evening onwards. and reaches a favorable position from 23:00 PM or midnight onwards. During this period, many astronomers choose to stay until the early hours of the morning, as the balance between the radiant's altitude and the darkness of the sky is better.
Although peak activity is concentrated in a few hours, the rain maintains a relatively wide beakTherefore, the entire night is usually productive. This means that even those who cannot observe at the peak of the meteor shower will still have reasonable chances of seeing a good number of meteors at other times during the night.
How the Moon affects the Geminid meteor shower
One of the key factors for enjoying the December meteor showers It is the state of the Moon. Its brightness can whiten the sky and cause fainter meteors to go unnoticed, significantly reducing the number of shooting stars visible to the naked eye.
In the most favorable scenarios, the lunar phase is around the new moon or during a very advanced waning moonso the band of dark sky coincides with the middle of the night. During the peak of the Geminid meteor shower, precisely a Waning moon, of moderate brightness and with a somewhat delayed appearance on the horizon.
This translates into several hours of useful darkness during the first part of the night, especially before the moonriseThis is the point at which the satellite's brightness begins to reduce the contrast of the fainter meteors. In Spain, this circumstance leads many astronomers to recommend taking advantage of the period between late afternoon/evening and the early morning hours.
Despite the presence of the Moon, the Geminids are still intense enough to put on a good show. The brightest meteors, including possible fireballsThey remain visible even with some moonlight. However, the further away you are from artificial light sources, the better the overall impression will be.
Tips for watching the meteor shower in December
To take advantage of the December meteor showersBeyond knowing the peak date, it's advisable to follow a series of practical recommendations. Many of them are simple, but they can make the difference between a frustrating night and a truly rewarding one.
The first thing to do is choose a the darkest place possibleaway from urban centers, busy roads, or powerful light sources. In Spain, rural inland areas, mountainous areas such as the Serra de Tramuntana in Mallorca Less populated areas of the peninsula and islands often offer better conditions than the surroundings of large cities.
It is also important that the horizon is free of obstacles (very tall trees, buildings, nearby mountains) and, if the Moon is present, it is advisable look in the opposite direction Adjust your position to gain some contrast. You don't need to point directly at the radiant; meteors can appear anywhere in the sky.
Contrary to what it may seem, the use of binoculars or telescopes to track a meteor shower. These instruments greatly reduce the field of view and make it difficult to follow the movement of the meteors, which are spread across the entire celestial sphere. The most effective method is usually to lie down or reclineLet your eyes adjust to the darkness for at least 20-30 minutes and observe patiently.
As December brings with it cold nightsEspecially in the interior of the Iberian Peninsula and mountainous areas, it's essential to bring sufficient warm clothing, blankets, a hat, and gloves if needed. A sleeping mat, a reclining chair, or even a sleeping bag will help you pass the time more comfortably and prevent the cold from ruining the experience.
What can you expect at first glance in Spain
The number that is most often mentioned when talking about the Geminids is their zenith hourly ratewhich is around 120 meteors per hour under perfect theoretical conditions. However, that number assumes a completely dark sky, no moon, a very high radiant, and no light pollution, something unusual near cities.
In realistic scenarios in Spain or other parts of Europe, those who travel to a rural and relatively dark environment may see between 40 and 60 shooting stars per hour at the best times of the night. The more light pollution the sky suffers, the lower the number of meteors becomes, as only the brightest ones are visible.
Many of the Geminid meteor showers are characterized by being clear, long-stroke meteorswith subtle colors (white, yellowish, or slightly greenish) that are easily visible to the naked eye. Occasionally, fireballs may appear—especially bright meteors that attract attention even when looking in another direction.
In spaces like the inland Mallorca or the Serra de TramuntanaFar from coastal urban centers, conditions are often ideal for enjoying the rain in the middle of the night, weather permitting. A similar pattern is repeated on the Iberian Peninsula and in the Canary Islands: the further you get from the coast and large towns, the better the rain will be.
Although the night of peak season is the most advisable, it also makes sense to plan a trip on dates close to the peak if the cloud forecast is better, as rain maintains a high activity for several days around the peak.
Ursids: the discreet rain that closes December
Besides the Geminids, another of the December meteor showers that are worth noting on the calendar are the UrsidsIt is a much more modest shower in terms of the number of meteors, but it appears right in the middle of the Christmas season, which makes it a perfect excuse for a night out if you are already in a rural setting.
The Ursids are associated with the remains of comet 8P/Tuttle and have their radiant in the vicinity of the constellation of Ursa MinorFrom latitudes like those of Spain, that point in the sky remains almost always above the horizon, making rain potentially observable during all night.
The period of activity ranges, approximately, between mid and late December, and the peak is usually on the night of 21 to December 22That is, its peak coincides with dates very close to the Winter Solstice, when the nights are especially long in the northern hemisphere.
Under optimal conditions, the activity rate of Ursids is around 10 meteors per hourAlthough the number can vary from year to year. In theory, it's not a spectacular shower in terms of quantity, but it can produce occasional flashes of light that are appreciated, especially if the sky is very dark and you observe it for a while.
One of the advantages is that its peak reaches close to the new moon phase or very thin waxingTherefore, the night sky is usually quite dark and there is no intense moonlight to reduce visibility. This increases the chances of spotting the fainter meteors in the shower.
How meteor showers fit into the December astronomical calendar
The December meteor showers These are not isolated phenomena, but rather part of a month packed with astronomical events. Alongside the peak of the Geminids and the Ursids, the Moon goes through its phases, conjunctions with bright planets occur, and the much-anticipated meteor shower arrives. Winter Solstice.
During the first few days of the month, the Moon reaches its full moon phase, traditionally known as the "cold moon" because it coincides with the coldest period of the year in the Northern Hemisphere. From then on, the satellite enters last quarter, it fades towards the new Moon and then it grows again until the waxing crescent at the end of the month.
For meteor showers, this evolution has a direct impact: the waning phase around the peak of the Geminids and the proximity of the new moon to the peak of the Ursids They allow you to enjoy stretches of fairly dark sky. Those planning their outings can check the moonrise and moonset times to choose the best times, usually the middle of the night and the hours before dawn.
In the same time frame, December 21st marks the official change of season with the arrival of astronomical winterThat day becomes the shortest of the year in terms of daylight hours, but in return it leaves one of the longest nights, ideal for dedicating time to both the Ursids and the observation of other objects such as star clusters or the Orion nebula.
For those looking to make the most of the December sky, it might be interesting to combine an outing to see the Geminid meteor shower with another close to the dates of the Ursids, thus taking advantage of both the intensity of the first and the especially dark sky offered by the second.
With all these phenomena, the December meteor showers These nights offer a great opportunity to break from routine, bundle up, and dedicate a few hours to observing the sky. Between the power of the Geminids, the discreet presence of the Ursids, and the long nights of the solstice, those who venture out to a dark location in Spain or elsewhere in Europe will have ample chances of enjoying shooting stars and a winter sky that rarely disappoints.