The December 2025 sky: shooting stars, supermoons, and cosmic wonders that close out the year.

December 2025 opens with an exceptionally rich sky full of astronomical events. The long winter nights and clear air offer ideal conditions for observing supermoons, meteor showers, bright planets, and even the passage of a comet from another star system. A month that, according to amateur astronomers, will be among the most spectacular in recent years.

The Long Nights Supermoon kicks off the month

The first event on the calendar is expected for Friday December 5: the superluna, the third and final of 2025. Our satellite will be at perigee, 356.961 kilometers from Earth, appearing 8% larger and 15% brighter than an ordinary full Moon.
Traditionally called Cold Moon o Moon of the Long Nights, owes its name to its proximity to the winter solstice, the period of the year in which night clearly prevails over day.

Geminids: The most intense shower of stars of 2025

From 4 20 to December the meteor shower will enter the scene Geminids, considered by astronomers to be the most prolific of the year. peak is expected between 13 and the 14 December, when they can be observed until 120–150 meteors per hour under dark, light-polluted skies.

What makes this swarm unique is its origin: the Geminids do not come from a comet, but from the asteroid 3200 Phaethon, an anomalous asteroid that sometimes displays cometary-like activity. The meteors appear slow, bright, and often colorful, with persistent trails that make them easily observable even to the untrained eye.

Next to the Geminids, among the 17 and the 26 December, they will also be visible Bears, a small swarm with peak 22th December, which delivers an average of ten meteors per hour.

Interstellar comet 3I/ATLAS grazes the Solar System

One of the most anticipated events by professional astronomers is the passage of the comet 3I/ATLAS, scheduled for the 19th DecemberDiscovered in July 2025, the comet comes from a remote region of the Milky Way: it is in fact the third interstellar object never identified after 'Oumuamua and Borisov.

ATLAS will move to approximately 269 ​​million kilometers from Earth, between the orbits of Mars and Jupiter. A telescope will be needed to observe it, but its presence in our sky represents a rare scientific opportunity: analyses by the James Webb Space Telescope have revealed an unusual composition, with high amounts of carbon dioxide, water, and carbon monoxide.

The winter solstice: the shortest day of the year

Il 21 December at 16: 04 it will happen winter solstice, the moment when the Sun reaches its greatest angular distance from the celestial equator. It marks the beginning of astronomical winter in the Northern Hemisphere and the day with the shortest hours of daylight. From this moment, the days will begin to lengthen, symbolically marking the rebirth of the sun's luminosity.

Conjunctions and Planets: The Last Show of the Year

December also offers a series of suggestive conjunctions:

• 7th December: the moon touches Jupiter, Castor e Pollux in the constellation of Gemini.

• 8th December: our satellite meets theNativity Cluster (M44) in the constellation of Cancer, a celestial picture with an almost Christmassy atmosphere.

• 31th December: the Moon closes the year approaching the Pleiades, with Aldebaran clearly visible in Taurus.

On the planetary front, Jupiter dominates the sky: it is observable throughout the night, while Saturn It appears in the early hours after sunset. Particularly favorable is also Mercury, That the 7th December It reaches its maximum western elongation and shines shortly before dawn towards the southeast. Almost impossible to see, however, Venere e Mars, too low on the horizon or bathed in sunlight.

The winter constellations are back in the spotlight

As the month progresses, the sky is enriched with the great winter constellations. Orione, with its unmistakable three-star belt, dominates the scene together with the Canis Major, where it shines Sirio, the brightest star in the firmament. The picture is completed by the Toro with the red giant Aldebaran and Gemelli, with the brilliant Castor and Pollux.

For those seeking a touch of Christmas poetry, the constellation ofUnicorn hosts the suggestive “Albero di Natale” stellar, while in the Cancer it is possible to locate the cluster of Nativity scene (M44).

A December to remember

Between meteor showers, supermoons, interstellar comets and suggestive conjunctions, December 2025 promises to be one of the richest months for astronomical observationA chance to rediscover the beauty of the winter sky and bid farewell to the year with a gaze turned toward infinity.