9 night sky events to see in December, from a supermoon to a once-in-a-lifetime interstellar comet
This month will bring some striking celestial sights, including one of the year’s best meteor showers and a glowing Saturn-moon pairing.
If November’s widespread aurora sightings left you buzzing, December is poised to keep the momentum going. This month’s nightscapes are packed with celestial standouts: early planet sightings, a bright supermoon, and what many astronomers consider 2025’s best meteor shower. Later in the month, an exceptionally vivid Jupiter will cap off a solid year of sky-watching—and hint at what’s coming in 2026.
Here are nine top night-sky sights to watch for this month. Most are visible to the unaided eye and are all best viewed from a remote, dark sky.
Supermoon—December 4
The final full moon of the year is also a supermoon. That’s when the space rock’s full phase coincides with its close approach to Earth, known as its perigee. At this time, the moon can appear up to 14 percent larger and 30 percent more luminous than when it’s at its farthest point from our planet, known as its apogee.
(How to watch the rare streak of 3 supermoons happening back-to-back.)
Mercury reaches greatest elongation—December 7
Mercury rarely strays far from the sun’s glare, but on December 7, it swings to its greatest elongation—its widest visible separation from the sun. It’s the best time to see the “swift planet” without the sun’s obscuring glow. Look for it around an hour or so before sunrise the morning of December 7. It will rise above the eastern horizon, with Venus following in tow.
For the most striking view, catch the moon as it rises around sunset in the eastern sky. An optical trick known as the moon illusion makes it appear extra huge—even more so when it’s around structures like buildings or trees.
Geminid meteor shower—December 13–14
Expect heaps of sky confetti during the Geminids’ peak from December 13–14. It’s historically one of the most prolific and reliable annual showers, producing anywhere from 60 to 120 meteors per hour during peak under pristine conditions. This year’s setup is exceptionally favorable.
The shower becomes visible around 10 p.m.; the peak night’s roughly 30-percent illuminated waning crescent moon won’t rise until around 2 a.m. That means, with clear, dark skies, astronomy enthusiasts can enjoy hours of uninterrupted meteor-scouting. Watch for the spectacle’s yellow-tinged streaks and especially bright flashes, known as fireballs, which can appear anywhere in the sky.
Optimal Orion nebula viewing—December 15
December is prime time to peer at the whimsical Orion Nebula. This star-forming region, a heap of dust and gas also known as Messier 42, is among the faintest objects humans can see with the naked eye. A telescope will sharpen the nebula’s signature features, including blue, pink, and green wisps.
The view is best on December 15, when it’s at its highest point in the night sky around midnight local time. Find this luminous star nursery beneath Orion’s familiar three-star belt.
Comet 3I/ATLAS makes closest pass to Earth—December 19
The seven-mile-wide Comet 3I/ATLAS will reach its closest point to Earth on December 19, passing around 170 million miles from us. Now through mid-December provides optimal viewing of this rare visitors. It’s just the third known interstellar object in history to pass through our solar system.
Astronomers believe the comet originated from a faraway star system in the Milky Way and could be over seven billion years old. The sight will not be bright enough for naked-eye visibility, but those with telescopes or access to observatories can monitor how the object survived its close pass by the sun in October. Look for it near the constellation Leo.
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(Interstellar comet 31/ATLAS is a weirdo, but it’s definitely not aliens.)
Winter solstice in the Northern Hemisphere—December 21
December 21 marks the year’s shortest day in the Northern Hemisphere, and the minimal daylight is a welcome treat for northern lights chasers. Of course, it’s tough to predict when a spectacular show like the mid-November aurora bonanza will happen again.
Still, since we’re on the tail end of solar maximum—the sun’s roughly 11-year peak in activity—we still have solid aurora odds. Here’s how to track geomagnetic activity, or where to plan your next aurora chase. Those seeking a respite from winter can head to the southern hemisphere, where the dates marks the longest day of the year.
Ursid meteor shower peaks—December 21–22
The Ursids aren’t as flashy as the Geminids or Perseids, but they’re still worth scouting, especially under this year’s dim, nearly new crescent moon. The height of activity strikes overnight from December 21–22.
(Here’s how to see a meteor shower during the winter solstice.)
You could see up to 10 meteors per hour under dark skies. The bulk of meteor activity occurs just before dawn, when the Ursa Minor radiant is at its highest, but the streaks could appear at any time of night.
Saturn-moon conjunction—December 26
The waxing crescent moon and Saturn will appear within roughly four degrees, or about three finger widths, of each other the night of December 26. Look for the pair in the southern sky after the sun sets. They’ll travel together until around midnight, when they set below the west horizon.
Jupiter brightens—Last week of December
Soon, Earth will soar right between the sun and Jupiter—a period known as opposition. It’s when the planet appears bigger and more luminous than usual. The official opposition doesn’t occur until Janurary 10, but the gas giant will brighten steadily from late December through that early 2026 event. Jupiter rises above the northeast horizon soon after sunset and will remain visible all night.
