Astronomical Events in December 2025: Explore the Night Sky This Month!
Find all the astronomical events of December 2025 in this guide! Comet forecast, promising meteor showers, the best time to see Mercury, the December solstice, and more. To easily find celestial objects in the sky, use the free astronomy app Sky Tonight. Let's get started!
Contents
- December Celestial Events Calendar: What’s Up in the Sky This Month
- December Moon Events
- Planets in December 2025
- Constellations in December 2025
- December solstice
- Meteor showers in December 2025: Geminids, Ursids
- Comets in December 2025
- How to navigate the night sky?
- Bottom line: celestial events in December 2025
December Celestial Events Calendar: What’s Up in the Sky This Month
We provide the event dates in GMT (Greenwich Mean Time). For your location, the exact times may vary. To find out the time and date of the event for your city, use the Sky Tonight astronomy app.
- December 1: Phoenicids’ peak (ZHR = variable);
- December 4: Super Full Moon 🌟, Lunar occultation of the Pleiades (mag 1.6) 🌟, Moon near Uranus (mag 5.6); Moon near Aldebaran (mag 0.8);
- December 7: Mercury (mag -0.5) at its greatest elongation 🌟, Puppid-Velids’ peak (ZHR = 10), Moon near Jupiter (mag -2.6) 🌟, Moon near Pollux (mag 1.2);
- December 8: Venus (mag -3.9) near Antares (mag 1.0), Moon near the Beehive Cluster, Asteroid Psyche (mag 9.7) at opposition;
- December 9: December Monocerotids’ peak (ZHR = 3), Sigma Hydrids’ peak (ZHR = 7);
- December 10: Lunar occultation of Regulus (mag 1.4);
- December 11: Neptune ends retrograde motion;
- December 12: Last Quarter Moon;
- December 14: Geminids’ peak (ZHR = 150) 🌟, Moon near Spica (mag 0.97), Jupiter (mag -2.6) near Pollux (mag 1.2);
- December 16: Comae Berenicids’ peak (ZHR = 3);
- December 18: Moon near Mercury (mag -0.5), lunar occultation of Antares (mag 1.0);
- December 19: 3I/ATLAS reaches closest point to Earth 🌟, Moon near Venus (mag -3.9), Mercury (mag -0.5) near Antares (mag 1.0);
- December 20: New Moon, Moon near Mars (mag 1.4);
- December 21: Solstice 🌟;
- December 22: Ursids’ peak (ZHR = 10) 🌟, lunar occultation of Pluto (mag 14.4);
- December 27: First Quarter Moon, Moon near Saturn (mag 1.0) and Neptune (mag 7.8);
- December 28: C/2024 E1 (Wierzchos) (mag 7) near Mars (mag 1.2);
- December 31: Lunar occultation of the Pleiades (mag 1.6), Moon near Uranus (mag 5.6).
The highlighted events are the outstanding events of the month.
About magnitude: the faintest magnitude for stars and planets visible to the naked eye in cities with moderate light pollution is about 4. Typical amateur binoculars allow you to observe objects with a brightness of 8-10 mag. Small-to-medium telescopes, when used under dark skies, help you see up to 12-13 mag.
December Moon Events
Moon phases in December 2025
- Full Moon: December 4, 23:14 GMT
- Last Quarter: December 11, 20:52 GMT
- New Moon: December 20, 01:43 GMT
- First Quarter: December 27, 19:10 GMT
Visit the Moon Phases section on our website. There, you can check out the monthly lunar calendar and find out the Moon phase for any specific day, as well as the moonrise and moonset times. Need a portable lunar calendar? Track the Moon’s phases anytime, anywhere with Sky Tonight or Star Walk 2.
The Last Full Moon of 2025 – December 4
The Full Moon occurs on December 4 at 23:14 GMT in the constellation Taurus. This Full Moon is traditionally called the Cold Moon (or Long Night Moon) in the Northern Hemisphere because it occurs near the winter solstice, when nights are long, and temperatures are low. What’s more, this Full Moon is also the last Supermoon of 2025, appearing about 8% larger and 15% brighter than average, though the difference may be subtle to the casual observer.
Regions north of the equator will enjoy seeing this Full Moon climb higher than any other Full Moon until 2042 thanks to a lunar standstill, which is when the Moon's path reaches the sky's extremes. Conversely, in the Southern Hemisphere, the Moon will appear unusually low on the horizon and will have a warm golden or reddish glow as it shines through thicker atmospheric layers.
Read more: December Supermoon 2025
The December Supermoon Hides The Pleiades – December 4
On the Full Moon night, the Moon won’t be alone! It will shine close to the Pleiades star cluster, creating a pretty scene for binoculars and cameras. The Pleiades can be seen with the naked eye under a dark sky, but the bright glare of the Supermoon will wash out many of the faint stars, so using optics is highly recommended.
For observers in northern Africa, most of Europe, and North America, the event will be even more impressive: the Moon will pass in front of the Pleiades, causing a lunar occultation. From these regions, you’ll see the Moon slowly cover and then uncover different stars of the cluster. For example, in San Francisco and Los Angeles, the Moon will move right through the core of the Pleiades, hiding some of its brightest stars, including Electra, Merope, Maia, and Alcyone. From Chicago, the Moon will skim the edge of the cluster, occulting stars such as Electra, Celaeno, Maya, and Taygeta. The occultation will last from 23:55 GMT on December 3 to 05:18 GMT on December 4.
Read more: The Pleiades Star Cluster
Moon Near Jupiter – December 7
On December 7, the 93%-illuminated Moon will pass close to Jupiter (mag -2.6), creating the glowing pairing. With Venus lost in the Sun’s glare this month, Jupiter stands out as the brightest starlike object in the night sky.
The two objects reach conjunction at 15:46 GMT, separated by 3°45′, and make their closest approach at 17:11 GMT, narrowing the gap slightly to 3°36′. You can find them in the constellation Gemini, rising low above the eastern horizon in the early evening. As the night progresses, the Moon and Jupiter will climb higher, reaching their highest point in the sky around midnight.
Read more: What Planet Is Near the Moon Tonight?
The New Moon – December 20
The New Moon arrives on December 20 at 01:43 GMT, bringing the darkest night of the month. With the Moon completely invisible, this is an ideal time for [deep-sky viewing]. Star clusters, nebulae, and distant galaxies will appear clearer, especially from locations with low light pollution. It is also a perfect time for meteor watchers: just two days later, the Ursid meteor shower reaches its peak, producing around 10 meteors per hour under favorable conditions.
Read more: December Deep-Sky Objects, Ursid Meteor Shower
Planets in December 2025
In December, Mercury, Jupiter, Saturn, Uranus, and Neptune are well-placed for observations. Venus and Mars are barely visible because they are located too close to the Sun.
Planets Visible in the Northern Hemisphere – December 2025
Mercury (Libra, Scorpius, Ophiuchus, Sagittarius): Well-seen in the morning sky, especially in early December. It rises low above the southeastern horizon and remains visible for up to an hour before sunrise. It reaches maximum morning elongation on December 8, making it easiest to observe then. Throughout the month, Mercury brightens from a magnitude of 0.08 to -0.58.
Venus (Libra, Scorpius, Ophiuchus, Sagittarius): Poorly visible, appearing only briefly at dawn before disappearing into the Sun's glare by late December. It moves toward superior conjunction on January 6, 2026, making observations increasingly difficult. During the month, the planet has a magnitude of -3.9.
Mars (Ophiuchus, Sagittarius): Sits low on the southwestern horizon after sunset and is difficult to observe as it approaches solar conjunction on January 9, 2026. Its brightness increases slightly from a magnitude of 1.3 to 1.1 by the end of the month.
Jupiter (Gemini): Dominates the sky all night and into the morning, offering excellent viewing conditions as it approaches opposition on January 10, 2026. Jupiter brightens from a magnitude of -2.5 to -2.7 through December.
Saturn (Aquarius): Appears in the sky as an evening object, visible after sunset but setting earlier as the month progresses. The planet’s rings remain thin but are slowly opening. Saturn’s brightness decreases slightly from a magnitude of 0.9 to 1.0.
Uranus (Taurus): Remains well-positioned in the weeks following its November opposition and can be seen for most of the night. Under exceptionally dark skies, it may be seen with the naked eye, though binoculars provide an easier view. The planet holds a steady brightness at a magnitude of 5.6.
Neptune (Pisces): Can be seen in the evening and night sky, but you will need at least a small telescope to observe it. On December 10, the planet will end its retrograde motion and return to direct motion. Its brightness remains steady at a magnitude of 7.9.
Planets Visible in the Southern Hemisphere – December 2025
Mercury (Libra, Scorpius, Ophiuchus, Sagittarius): Well-seen in the morning sky, especially in early December. It rises low in the east-southeast about an hour before sunrise. The planet reaches maximum morning elongation on December 8, making it easiest to observe then. Throughout the month, Mercury brightens from a magnitude of 0.08 to -0.58.
Venus (Libra, Scorpius, Ophiuchus, Sagittarius): Rises low on the east-southeastern horizon at dawn and fully disappears into the Sun's glare by late December. It moves toward superior conjunction on January 6, 2026, making observations increasingly difficult. During the month, the planet has a magnitude of -3.9.
Mars (Ophiuchus, Sagittarius): Mars rises after the Sun and shows up only briefly as a low, fading point in the west after sunset. Its visibility is poor as it approaches solar conjunction on January 9. Even though it brightens a bit from magnitude 1.3 to 1.1, it remains a difficult target due to its low altitude.
Jupiter (Gemini): Dominates the sky all night and into the morning, offering excellent viewing conditions as it approaches opposition on January 10, 2026. Jupiter brightens from a magnitude of -2.5 to -2.7 through December.
Saturn (Aquarius): Appears in the eastern sky at dusk and sets earlier each night. The planet’s rings remain thin but are slowly opening. Saturn’s brightness decreases slightly from a magnitude of 0.9 to 1.0.
Uranus (Taurus): Remains well-positioned in the weeks following its November opposition and can be seen for most of the night. Under exceptionally dark skies, it may be seen with the naked eye, though binoculars offer a clearer view. The planet holds a steady brightness at a magnitude of 5.6.
Neptune (Pisces): Can be seen in the evening and night sky, but you will need at least a small telescope to observe it. On December 10, the planet will end its retrograde motion and return to direct motion. Its brightness remains steady at a magnitude of 7.9.
Best Time to See Mercury – December 7
On December 7 at 20:59 GMT, Mercury reaches its greatest eastern elongation, located 20°42′ from the Sun in the sky. This is the best time to observe Mercury, a planet that usually hides in the Sun’s glare. Shining at a magnitude of -0.5, it will be visible to the naked eye in the constellation Libra. Look for the elusive planet on the south-eastern horizon about 30 minutes before local sunrise.
Although the greatest elongation always marks the planet’s prime viewing window, not all elongations are equal. This one strongly favors the Northern Hemisphere thanks to the steep angle of the ecliptic to the horizon at this time of the year. It’s the best morning apparition of Mercury for northern observers in 2025!
Don’t limit your observations to just December 7: Mercury is visible in the mornings from early December and maintains a magnitude of around -0.5 (bright, but competing with dawn light) until around December 25. Then the planet will gradually disappear into the morning twilight.
Read more: What Is Elongation in Astronomy?
Constellations in December 2025
In the Northern Hemisphere, the best visible constellations in December are the well-known Orion, Perseus, Aries, and Taurus. The last two belong to the constellations of the zodiac.
In the Southern Hemisphere, December offers a chance to see Eridanus, the sixth largest constellation in the sky, as well as fainter Fornax and Horologium.
To easily locate any of the 88 constellations in the sky, use the free astronomy app Sky Tonight. Simply type in the name of the constellation you want, tap the target icon, and the app will show you its location based on where you are.
Read more: December Constellations
December solstice
On December 21, at 15:03 GMT, the Earth’s Northern Hemisphere will reach its maximum tilt away from the Sun, creating a phenomenon called the winter solstice. People there will experience the shortest day of the year, as the northern half of our planet will have the least amount of daylight. Astronomically speaking, this event marks the beginning of winter in the Northern Hemisphere, which will last until the vernal equinox. Our ancestors attached great importance to this day and celebrated it with various festivals – learn more about these peculiar traditions in the article dedicated to the winter solstice.
On the same day, the Southern Hemisphere will tilt closest to the Sun and experience the summer solstice and the longest day of the year. The summer solstice marks the beginning of astronomical summer, which will last in the southern latitudes until the autumnal equinox.
By the way, the other planets in the Solar System also have seasons – on Uranus, for example, summer lasts 21 years! Learn more in our article about the summer solstice.
Meteor showers in December 2025: Geminids, Ursids
In December, nine meteor showers reach their peaks. Among them, the most promising are the Geminids and the Ursids.
The Geminids, which peak on December 13-14, are the best and most reliable of the major annual meteor showers. Under dark skies, observers can see up to 50 meteors per hour, and during the peak, counts climb to 150 meteors per hour! In the Northern Hemisphere, Geminid meteors are visible from the local evening, while in the Southern Hemisphere, they rise higher around midnight. In 2025, the 40%-illuminated waxing crescent Moon won’t interfere much, creating excellent viewing conditions. For the best view, look away from the Moon and give your eyes 20–30 minutes to adapt to the dark.
The Ursids deliver a more modest display of 10 meteors per hour during their peak on the night of December 21-22, but they are known for occasional brief outbursts. They favor the Northern Hemisphere, where the radiant near the star Kochab stays high in the night sky. In 2025, the Ursids reach their peak just two days after the New Moon, providing ideal viewing conditions. Try observing after midnight, when the radiant climbs higher and rates increase.
Read more: December Meteor Showers
Comets in December 2025
In December 2025, there are no comets bright enough to see with the naked eye, but a couple of them are well within reach of small telescopes.
Comet 3I/ATLAS, the much-discussed interstellar visitor, will make its closest approach to Earth on December 19. At a magnitude of about 13, it can be spotted with small telescopes (80–150 mm) under dark skies from both hemispheres. Look for it in the constellation Leo in the early morning hours. Don't wait to observe it – as the year ends, the comet will move away and eventually leave the Solar System.
Another target, Comet C/2024 E1 (Wierzchos), is also visible this December and favors observers in the Northern Hemisphere. With a brightness of around magnitude 10, it can be observed through small telescopes in the constellation Sagittarius shortly after local sunset.
In December 2025, the best date to see and photograph Comet Wierzchos is December 28, when it passes close to Mars (mag 1.2), coming within 2°04′ at 15:15 GMT. To be sure you don’t miss this, search for C/2024 E1 (Wierzchos) in the Sky Tonight astronomy app and set a notification for its rise time on December 28.
Another comet to watch in December is 24P/Schaumasse. At a magnitude of around 11, it can be seen through small telescopes. It lies in the northern constellation Coma Berenices, and is visible from around local midnight until morning twilight in the Northern Hemisphere. In the Southern Hemisphere, it appears a couple of hours before sunrise. The comet is slowly brightening and may become visible in binoculars by early January 2026.
Comet 210P/Christensen, which was at its brightest in November, is still observable as well. At a magnitude of around 12, it is within reach of a small telescope from both hemispheres. Look for it before local sunrise in the constellation Libra.
Read more: 3I/ATLAS, Upcoming Comets.
How to navigate the night sky?
For non-professional astronomers, the night sky can be tricky and confusing. Which of these bright dots is Venus? Where to look to find a particular comet in the sky? The easiest and fastest way is to use an astronomy app like Sky Tonight. It's free to use, works without an internet connection, which is useful when camping, and includes a handy astronomical calendar.
Open the app, point your phone at the sky, and Sky Tonight will tell you the names of constellations, stars, and more. If you want to get really good at knowing what's in the night sky, there are videos that can teach you how to use the app.
Also, you can test your practical skills in night sky observation with the quiz! Are you just a newbie stargazer or an almighty Astro Maestro? Find out!
Bottom line: celestial events in December 2025
December 2025 has it all: a final Supermoon that brushes past the Pleiades, Mercury’s best morning visibility, the powerful Geminids, the December solstice, and even comets like 3I/ATLAS and C/2024 E1 (Wierzchos).
To turn this list of events into real observing sessions, let Sky Tonight guide your way. It shows you where each event appears in the sky above you, and lets you set reminders so you don’t miss a meteor peak or a rare comet pass. Just open the app, point your device at the sky, and enjoy December’s night sky!
