By “Astro” Mark Laurin
Used with permission.
Winter is here. In all fullness the shortest day and the longest night arrives on December 21st. Those living in the northern hemisphere at the dawn of humanity saw the autumnal Sun continue to fall in the sky in fear it would not return. The end was near. Yet, the winter solstice took place and the Sun did indeed return. They lit fires and torches. They danced and celebrated.
With this in mind, go outside any clear cold night this December. Look up. As you do, feel the skin on your face contract from the cold’s touch; watch the condensation of your breath form a cloud to rise and dissipate. Permit the dancing pinpricks of light; jewels, big and small, in colors of brilliantly blue, sharp white, dim yellow, and soft copper to capture your awareness. Give way to the magic of the moment washing over you. Then, out of nowhere a flash, streak, ignite, bomb! A meteor breaks through the serene scene. December is full of meteor showers, of major and minor classification, capable of radiating from anywhere overhead at any time of the night. Are you ready? Come outside with me and look up with a reason to dance and celebrate the season’s celestial events.
Geminids Meteor Shower: Peak December 14th
The annual Geminids meteor shower is a major meteor shower and is active from the 4th through the 17th of December. For 2023, the shower peaks on December 14th. The meteor shower radiates within the constellation Gemini (see above). This year it is estimated there will be less than the average peak of 150 meteors per hour. Gemini will rise above the east-northeastern horizon after 7pm MT. You’ll see the most meteors after Gemini has risen higher in the sky around 2am MT. This is the best time to see the most meteors on the 14th. You can expect to see up to 119 meteors per hour. The year’s shower will be even better as it will peak close to a new Moon. This means minimal Moon light and that means you’ll see the more faint meteors fly across the night sky.
The Winter Solstice: December 21st
This year, the winter solstice occurs on December 21st at 8:24pm MT. It is the moment when the Sun reaches its most southern point in the sky, and thus the first day of winter in the northern hemisphere. Conversely, in the southern hemisphere, the Sun is above the horizon for longer than on any other day of the year. Thus, the first day of summer. All this happens because of the Earth’s angle of its axis, tilted at an angle of 23.5° to the plane of its orbit around the Sun. As this angle is fixed throughout the Earth’s orbit, sometimes the Earth’s north pole is tilted towards the Sun (June), and at other times it is tilted away from it (December). Take heart, the days now get longer. Sadly though, not necessarily warmer for us up here in the north.
Ursids Meteor Shower: Peak December 23rd
Another major meteor shower in December is the Ursids meteor shower. See them streak through the night from December 17th through December 23rd. That’s correct, this shower overlaps with the Geminids. At their peak, the Ursids produce around 10 meteors per hour. The shower is visible from sunset to sunrise because the constellation Ursa Minor (Little Dipper) is circumpolar. It rotates around the northern hemisphere’s celestial North Pole, the star Polaris. Oh, and the end of Little Dipper’s handle is Polaris. So to find the radiate point, look north. The later in the evening / early morning you look, the higher the radiate point is in the northern sky. A benefit of this shower is you don’t have to crane your neck and stare straight up to see the radiate point. Assume a comfortable position and enjoy. Remember, that meteors can radiate from anywhere in the night sky, so keep a keen eye and a wide, panoramic view.
Don’t Call Us Minor. Monocerotids, Coma Berenicids, December Cassiopeid, December Leonis Meteor Showers: The entire month of December
Meteor showers are categorized into classes. The Geminids and Ursids are Class I, while the Monocerotids, Coma Berenicids are Class II, while the December Cassiopeid and December Leonis are Class IV. A class is determined by the shower’s ZHR, the Zenith Hourly Rate. That is the average meteors visible per hour if the radiant is directly overhead. A Class I meteor shower is a ten or better ZHR. Remember that the name of the meteor shower denotes the specific constellation from where the meteor shower will originate, and the radiant point is the more specific area within the constellation where the meteors will emanate. That said, never forget that meteors can appear, streak, flash, explode, and smoke from anywhere and at any time in the night sky. What fun is that?
A Mistletoe Kiss. The Moon and the Seven Sisters: December 24th
And who can resist a kiss under the mistletoe during the holidays? Even the biggest celebrities of the night sky can’t as they celebrate the holiday season too. This year, the Moon gets more than a handful as the splendidly blue-hued open star cluster commonly called the Seven Sisters (also known as the Pleiades, M45 and the Mini Dipper) come together for a warm seasonal embrace and a kiss on the cheek. That’s seven kisses. The Moon, quite a lucky guy. How about you? Why not take your special someone outside into the night for the same experience? You can bet the Moon and the seven daughters of Atlas and Pleione will be right there with you joining in an embrace and a kiss.
High above us this Christmas Eve night, Princess Andromeda will journey home upon the winged horse Pegasus with her hero Perseus and joined on their way by the Moon, the Seven Sisters, and the King of Sky, Jupiter. It will be a splendid seasonal gathering as major and minor meteors showers add to the merriment. Together they will be up all night for you to step outside briefly and look up for a truly magical moment.
As a child, I stayed up late on Christmas Eve and stared with wonder at the stars and planets from my bed through a frosted bedroom window. On that night when sleep never arrived, viewing the stars filled my heart. I hope they do for you. Consider them a gift from the cosmos.
Clear skies to you and happy holidays to one and all!
