December 2023 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 2023 Star Gazing Guide!
Well here we go junior scientists it's time for our final Star Gazing Guide of 2023 so here's a few fun facts about our night sky. This month we have the earliest sunset of the year on December 9th when our sun sets at 4:44 p.m. December also gives us the longest night of the year taking place on the winter solstice when the darkness lasts for 6 and 1/2 hours longer than it did on the summer solstice back in June. Incredible!
This month we talk belts and planets, a long lasting Full Moon, the greatest meteor shower of the year and we even learn about the winter solstice... all this and more we just take some... time to look up.
Our best seen constellations this month are Perseus, Triangulum and Aries. These are visible in Eastern sky at sunset and climb higher and higher overhead as the night goes on disappearing behind the western horizon before sunrise. Our winter skies mark the return of perhaps the most recognizable constellation in the world, Orion the Hunter. Visible in both the Northern and Southern hemispheres this constellation is immediately identified by an asterism comprised of three bright stars in a nearly straight line called Orion's Belt. I want you to see if you can spot Orion this month junior scientists and we'll talk more about it in next month's video.
Jupiter and Saturn continue to dominate our evening skies in the southwest with Jupiter visible until early morning throughout December and Saturn disappearing below the horizon before 9:00 p.m. by the month's end. Venus will be with us in the morning all month long best viewed at the beginning of the month and right next to the sliver of the waning crescent moon on the 9th. Mercury can be seen low in the Southwest and Western sky just after sunset at the beginning of the month but you'll be able to end your year on the best view of Mercury an hour before sunrise in the Southeast on December 31st.
Our full moon this month takes place on December 26th at 7:33 p.m. Eastern Standard Time and is referred to as the Cold Moon. Since this occurs so close to the Winter Solstice December's full moon will have the highest trajectory in the sky of any full moon this year and will actually appear to be very full for a few days before and a few days after this, meaning if you're celebrating anything over those few days you'll have a beautiful sky under which to celebrate.
Indigenous cultures around the globe have their own names for the Full Moons depending upon the time of year when they occur and on what is happening in nature around them. The December full moon appears to fill our night sky for several days, more than any other Moon of the year, and in the Great Lakes region the Ojibwe refer to these moons as "Spirit Moons”.
The Mi'kmaw of the East coast refer to it as the Full Chief Moon: Kesikewiku's, or Kjiku’s for short.
The Geminids meteor shower peaks on the night of December 13th and the morning of December 14th and is often considered to be the most dazzling meteor shower of the year. As the Earth passes through the debris left behind by the asteroid 3200 Phaethon, we should see the burning remains shoot across our skies appearing to emanate from the constellation Gemini high in the Southeast. This year the new Moon occurs on December 12th resulting in a very dark sky meaning that after midnight we should be able to see up to 120 multicolored meters an hour appearing anywhere up there.
The first official day of winter is December 21st and is defined by the winter solstice. What’s a solstice? Well…
We say that the earth has an axis that it rotates about. It's like an imaginary line that joins the north and the south poles. Every full rotation is one day and that takes 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 degrees.
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 will experience the least daylight hours that it gets in a single day all year. As a matter of fact the arctic circle experiences no daylight at all! Just 24 hours of darkness. Dec 21st is often referred to as the shortest day of the year which is kind of confusing since a day only has 24 hours, in reality we just experience the least amount of daylight hours on the solstice.
As we head towards summer the daylight hours will now begin to increase in length and the nighttime hours will get shorter.
Well that’s it! An action-packed month to end our year on! Whatever you may or may not celebrate this time of year I wish you nothing but a happy time of relaxation, enjoyment and clear skies. And while you may be taking a break from your studies just remember that there’s always time… to take some time… and look up.
See you next year 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 preparing our star gazing guide and the Royal Astronomical Society of Canada.