The moon is new Dec. 1. By Dec. 4, the moon’s thin sliver in the west is joined by Venus, just two degrees to the north. Dec. 8, Saturn is a mere 0.3 degrees south of our first-quarter satellite, occulted for viewers in the Southern Hemisphere. The moon is at perigee (closest to Earth) Dec. 12 at 365,361 kilometres Dec. 13, with the waxing gibbous moon among the stars of the Pleiades, Uranus is four degrees south.
Jupiter is five degrees south of the moon on Dec. 15, which will be full Dec. 16. Might be a good time for a photo opportunity.
Dec. 18 sees the moon occulting Mars for observers in the extreme north of Canada – otherwise a close conjunction of less than a degree. Dec. 24, the moon is at apogee (farthest from Earth) at 404,485 kilometres. That evening sees Spica hugging Luna at only 0.2 degrees away. Spica is the bright star in Virgo, the Maiden. Dec. 28 has the red star Antares just 0.09 degrees north of the moon, an occultation in the Southern Hemisphere. And, finally, 29 days later, the moon is new again Dec. 30.
Mercury is too close to the sun for safe viewing during the first half of December. It rises in the early morning eastern sky, skirting north of Antares Dec. 22.
Venus is prominent in the western evening twilight and joined by the moon Dec. 4. Each passing day sees the brightest planet rise higher and higher.
Mars is among the stars of Cancer, the Crab, rising just a half hour after Orion to the west. The Red Planet begins retrograde motion Dec. 7, seemingly moving westward (but it’s the Earth moving faster that causes this strange behaviour). The planet is well placed for evening viewing, with Pollux and Castor a bit north, Orion to the west, and Jupiter high above.
Jupiter is well placed for evening viewing among the stars of Taurus, The Bull. The moon is 5 degrees north Dec. 15th.
Saturn rises in early afternoon, making an appearance at sundown, a little to the northeast of Venus. The Ringed Planet is approaching a ring crossing in March 2025, so the rings gradually become edge-on. Unfortunately, the ring crossing occurs when Saturn is hidden by the sun, so a non-event.
Uranus rises in the late afternoon, ahead of Jupiter. The Pleiades are easy to spot just to the northwest of Jupiter, so the blue-green Uranus may be picked out of the starry background. It’s the spot that doesn’t twinkle.
Neptune, the elusive planet. It’s so far away that it looks impossibly small. You’d have to use powerful binoculars or a medium-powered telescope to see it, and even then, it’s a tiny spot. The blue planet is among the stars of Pisces, the Fish.
Winter solstice is on the early morning of Dec. 21.
The Geminid meteors peak on the evening of Dec. 13.
The Ursid meteors peak on the morning of the Dec. 22.
James Edgar has had an interest in the night sky all his life. He joined the Royal Astronomical Society of Canada in 2000, was national president for two terms, is now the editor of the Observer’s Handbook, and production manager of the bi-monthly RASC Journal. The IAU named asteroid 1995 XC5 “(22421) Jamesedgar” in his honour and in 2021 he was awarded a Fellowship of the RASC.
