December 2025 Stargazing Guide

Greetings, junior scientists, scientists, and citizens of this great big, weird, wild, and wonderful world in which we live. As always, I'm your humble science communicator, the great Orbax, coming to you from the Department of Physics here at the University of Guelph and I'd like to welcome you to our December 2025 Star Gazing Guide.

With the holiday break just around the corner, our chilly winter skies beckon us to gaze upon them. Sunset this month holds steady at 4:46 p.m. on the 1st and barely moves to 4:54 p.m. by the 31st. Sunrise this month does shift slightly, starting up at 7:35 a.m. and bumping back to 7:54 a.m. by New Year's.
But as we pass the solstice on December 21st, our daytime hours will actually start to lengthen as we slowly but surely approach springtime.
So, what should we be looking for in December?
This month, we cast our eyes skyward for a hero,
learn about the winter solstice,
and luck out with not just one, but two meteor showers.

All this and more when we just take some time...

to look up.

So last month we briefly mentioned the constellation Andromeda and in doing so we referenced the myth of Perseus.
In Greek myth, Perseus saved Andromeda from a sea monster with the help of Pegasus after just having slain the Gorgon Medusa.
It was the basis for the movie Clash of the Titans.
No, not not this one.
The good one.

Look to the north just after sunset.
Look high in the sky and if you remember last month's guide, you should be able to spot Cepheus and Cassiopeia.
Follow along to the east like we did last month to find Andromeda.
Below Andromeda is a collection of stars that kind of looks like a wishbone.
This is Perseus.
Perseus contains the open clusters NGC869 and NGC884 known as the Double Cluster or Caldwell 14.
Now, the Double Cluster may be visible to the unaided eye, but definitely visible with binoculars or even by taking a photo with your phone.
And you know what?
If you follow a line from Perseus up through Andromeda and look straight overhead, you'll notice a giant square asterism made of four stars.
This square is part of the constellation Pegasus and will be visible just after sunset for the rest of the winter.

Planet spotting this month is easy, but we're only going to be able to see a few.
Saturn will be bright and easy to spot, already up in the south at sunset.
Jupiter will rise a few hours later, but it will be big and bright late in the evening until sunrise, a beautiful view for our December mornings.
Mercury would be visible just before sunrise in the southeast and on the morning of the 17th, about 20 minutes before sunrise, the waiting crescent Moon and Mercury will be close enough to each other to fit in the same field of view of a pair of low-powered binoculars.
Good luck, junior scientists.

Our Full Moon this month takes place on December 4th and is the last of three Supermoons in 2025.
For more info on what a supermoon is, check out last month's guide.

The Mi'kmaw of the East coast name the upcoming December Full Moon as the Rivers Freezing over Moon, Keptekewiku's. Settlers refer to the onset of winter by calling this the Cold Moon, as well as other names such as Long Night referring to the closeness of the Full Moon to the winter solstice. This feature is also captured in many of the first nations names, with the Ojibwe referring to both Full Moons around the winter solstice as "Spirit Moons”.

As a matter of fact, the Winter Solstice occurs on December 21st and is officially the first day of winter.
What's a solstice?
Well, we say that the Earth has an axis which it rotates about.
It's like an imaginary line that joins the North and the South Poles.
Every full rotation about this axis is 1 day, which we define as 24 hours.
Now, this axis isn't perfectly perpendicular to the plane of our orbit around the Sun. It's actually tipped at 23.5°.
The Summer Solstice back in June marks the day that the North Pole is tipped closest towards the Sun.
The Winter Solstice on December 21st, however, marks the day that the North Pole is tipped furthest away from the Sun.
And, it is then that the northern hemisphere experiences the least amount of daylight hours that it gets all year long.
As a matter of fact,
the Arctic Circle experiences no daylight at all!
Just 24 hours of darkness. December 21st is often referred to as the shortest day of the year, which is kind of confusing since the day always has 24 hours in it.
In reality, we just experience the least amount of daylight hours on the solstice.
After the 21st, as we head towards the summer, the daylight hours will now begin to increase in length, and the nighttime hours will become shorter.

This month, we've got two meteor showers taking place.
The Geminids are considered to be one of the best meteor showers of the year with over 120 multicolored meteors per hour and named for its radiant,
the constellation Gemini.
Peaking on the night of the 13th to the morning of the 14th, look towards the skies after midnight.
A waning crescent Moon joins us for the party, but should only obscure the dimmest of shooting stars.
Now, on the night of the 21st and the morning of the 22nd are the Ursids,
named for their radiant Ursa Minor.
While the Ursids are nowhere near as active as the Geminids with only 5 to 10 meteors per hour as compared to 120, our moonless sky that night should stay dark enough for some excellent viewing.
Good luck, junior scientists.

So much excitement in December.
And while it is typically quite cold, I know many of you have time off during the break.
Time off that you can use to gaze into the darkened winter skies.
Time off to explore the beauty of the cosmos.
and time off to take some time...
and look up.

See you next month, junior scientists, and don't forget to have a science-tastic day!

Special thanks to Royal City Science's own planetary geochemist, Dr. Glynis Perrett for her help in preparing our star gazing guide
and the Royal Astronomical Society of Canada.