During this final week of 2022, we can observe what I would call "The Christmas Sky."
In many ways there are signs of the holiday season in our current evening sky. At this time of year many bring up the subject of the Star of Bethlehem. If you look low toward the southwest horizon about 30 minutes after sundown, you'll see a brilliant object that might remind you of that fabled apparition. Indeed, it's so bright that appears more like a dazzling beacon as opposed to a star: it's the planet Venus, the brightest of all the planets and the third brightest object in our sky next to the sun and the moon.
And don't forget to look for a jolly guest in the night sky this Christmas: Santa Claus! You can track Santa's whereabouts on Christmas Eve thanks to NORAD's annual Santa Tracker.
Related: Ursid meteor shower shines with ideal dark sky conditions this year
Joe Rao is a veteran meteorologist and eclipse chaser who also serves as an instructor and guest lecturer at New York's Hayden Planetarium.
A Christmas Eve celestial ornament for 2022
If you are blessed with clear skies on Saturday evening (Dec. 24) — Christmas Eve — you'll have a view of a gathering of three celestial objects low in the southwest sky beginning about a half hour after sundown. It's a trio composed of a slender crescent moon roughly 36 hours past new moon phase and situated off to the moon's right will be the planets Venus and Mercury.
Basically, an isosceles triangle configuration and a striking one it will be!
The moon and Venus form the base of the triangle, measuring roughly seven degrees in length, while Mercury serves a marking the peak of the triangle, roughly four degrees from both the moon and Venus. Here is an eye-catching holiday array which will be evident for a short while after sunset — but look quick! By an hour after sundown, the trio will be all but gone, already dropping below the horizon.
The Northern Cross
The Yuletide evening sky is especially rewarding now. The eastern sky is filled with brilliant stars — sort of a celestial Christmas tree. Distinctive groupings of stars forming part of the recognized constellation outlines, or lying within their boundaries, are known as asterisms.
One of the most famous is in the northwest these frosty evenings. Originally known simply as the "Bird" in ancient times, without any indication of what sort of bird it was supposed to represent, it later became the constellation Cygnus, the Swan. But the brightest six stars of Cygnus compose an asterism more popularly called the Northern Cross.
Bright Deneb decorates the top of the Cross. Albereo, at the foot of the Cross, is really a pair of stars of beautifully contrasting colors: a third magnitude orange star and its fifth magnitude blue companion are clearly visible in even a low power telescope. While usually regarded as a summertime pattern, the Cross is best oriented for viewing now, appearing to stand majestically upright on the northwest horizon at around 8:30 p.m. local time, forming a most appropriate Christmas symbol.
Interestingly, just before dawn on Easter morning, the Cross lies on its side in the eastern sky.
The Christmas Package
The legendary French astronomer Nicolas Camille Flammarion (1842-1925) referred to the three belt stars of Orion as "The Three Kings." And if we were to consider these three stars as representing the Magi, then not too far away, to the east, within the faint zodiacal constellation of Cancer, is the star cluster known as Preasepe, the Manger.
Want to get a better look at Orion's belt or Preasepe? We recommend the Celestron Astro Fi 102 as the top pick in our best beginner's telescope guide.
A manger is defined as a trough or open box in which feed for horses or cattle is placed. But the Book of St. Luke in the Christian Bible also tells us that the baby Jesus, wrapped in swaddling clothes was set down in a manger because there was no room at the Inn. In our current Christmas week evening sky, Preasepe represents the manger where Christ was born.
To the unaided eye, the manger appears in the middle of the dim constellation of Cancer as a soft, fuzzy patch or dim glow. But with good binoculars or a low-power telescope, it is a beautiful object to behold, appearing to contain a splattering of several dozen stars. Using his crude telescope, Galileo wrote in 1610 of seeing Preasepe not as one fuzzy star, but as "a mass of more than 40 small stars."
Three other planets
And last but certainly not least, are three more planets adorning our Christmas evening sky. As the sky becomes fully dark about 90 minutes after sunset, face about one-quarter up from the southwest horizon to see "the lord of the rings," Saturn, resembling a bright yellowish-white star. Your clenched fist measures about 10-degrees, so Saturn will appear a little more than "two fists" above the horizon. A telescope magnifying 30-power or more will reveal Saturn's famous rings, now tilted about 14 degrees to our line of sight.
Higher up in the south-southwest and shining nearly 20 times brighter than Saturn, is Jupiter, the largest in our solar system and a superb telescopic showpiece with clouds bands crossing its disk, as well as its retinue of four large moons.
And finally, about one-third up in the east, shining with a fiery orange color is Mars, shining with a radiance quite similar to Sirius, the brightest star in the sky. Just over three weeks ago, Mars made the closest approach it would make to Earth until the year 2033. Now it is receding and will grow progressively fainter in the coming weeks. But right now, it still stands out in our glorious Christmas sky.
Happy holidays!
Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for Natural History magazine, the Farmers' Almanac and other publications. Follow us on Twitter @Spacedotcom and on Facebook.
