What's Up in the Sky - December 2012

Fred Barrett | Nov 29, 2012

December is always a great month for stargazing.

A telescope shows Mars as a tiny dot low in the southwest about a fist width at arm’s length (10 degrees) just after sunset.

Venus is 5 degrees below Saturn in the southeast in the early days of December. This sight is for you early risers. They are very prominent about an hour before sunrise about 20 degrees above the horizon. As the month progresses, Venus moves lower and Saturn higher until, by month’s end, Venus starts to disappear into the sunrise.

Between the 9th and 11th, Mercury is to the lower left of Venus. It is the bottom dot in a diagonal line that connects the dots of Venus and Saturn. It will disappear with Venus near month’s end.

Venus is an excellent guide for finding Saturn in the southeast during this period. Saturn rises at 4pm in early December and has its rings tilted to about 18 degrees. This spectacular telescopic view is available throughout December.

Jupiter is in opposition on December 2nd. It rises in the east at sunset and is high in the south by 11pm, slowly sinking in the west to set at dawn. It is a blazing light up and to the right of the hourglass shape of Orion and sits in the midst of the Hyades star cluster. When I walk up my road to get my morning Citizen about 5:30am, it is slowly sinking towards the western horizon and with Orion trailing behind, presents a breathtaking sight. You can’t miss it! On December 25th, it is very close, about one degree above the Moon – the two brightest objects in the sky.

On December 21st at 6:12am EST, the Sun reaches solstice and it is the official start of winter in the North and summer in the South. It is the shortest day and the longest night.

Full Moon this month occurs on December 28th. It is called the Full Cold Moon or Full Long Nights Moon. It usually lives up to its name!

First seen in 1934 and rediscovered in 1989, the asteroid Toutatis, named after a god of ancient Gaul, will pass close to Earth. It returns every 4 years and on the night of the 11th and 12th, it will be at its closest – 0.046 AU or 6.9 million kilometers. We’re safe for several centuries and it is likely that gravitational interaction with Earth and Jupiter will eventually fling it far, far away.

I’ve saved the best for last! The Geminid meteor shower peaks on the night of December 13th and 14th. It will be a moonless night and the faintest of meteors will be visible. Expect about 150 meteors per hour and the best time is from 9pm to sunrise. Watch for activity a few days before and after the peak. Send me a report on how you did. Trace the shape of Gemini, including prominent stars, in the centre of a sheet of paper and draw a line for every meteor you see. If the line can be drawn back to Castor in Gemini, it is a Geminid. Most of them will be Geminids but the odd meteor will be from some other part of the sky and they are called sporadics. Don’t forget that meteors can appear all over the sky, not necessarily close to Gemini.

Watch for a special column on the Star of Bethlehem for the Christmas issue.

If you have questions or suggestions, Fred Barrett may be contacted at This email address is being protected from spambots. You need JavaScript enabled to view it.

The Beginner’s Observer’s Guide by Leo Enright is available at the Sharbot Lake Pharmacy or by contacting the Royal Astronomical Society of Canada www.rasc.ca/publications, subscriptions for our very own excellent Canadian astronomy magazine, Sky News, are also available from RASC..