I couldn’t possibly talk about December observations in 2020 without starting with the exciting planet-related event happening this month. Jupiter and Saturn will converge for their closest conjunction for the first time since the year 1226! Coinciding with the Winter Solstice on 21 st December, the “Great Conjunction of 2020” will see our 2 largest planets separated by just 0.1degrees (roughly 1/5 the width of the moon). This spectacle isn’t going to happen again before 2080, so get out there. Sunset will occur at 15:39 in Edinburgh on that day, so at about 16:30, if you look 10 degrees above the horizon to the S/SW, you should see them, appearing to shine almost as one.
Also, this month, we find the Geminids meteor shower. This spectacle will reach a peak at roughly 1 am on the 13th /14th December when it is possible to observe 100 meteors per hour. Look for the Gemini constellation and the star known as Castor within and they should be streaming away from that point.
There are many other astronomical objects to check out this month: Mars is will be shining brightly with an unmistakable reddish glow (look towards the South) and if you’re more of an early bird, you should be able to catch Venus (rising at about 5.30 am at the start of the month) if you look towards the SE (being close to the sun, it can only be seen shortly before sunrise).
Looking to the North, you will be able to see perhaps the most famous of all the constellations, The Plough. Find this, and you can find Polaris, the Pole Star. Polaris can be found by following the “handle” of the Plough to the end- follow this and you’re looking North.
Another well-known constellation is Cassiopeia (my personal favourite!)- this one will appear as a giant “M” in the sky (or “W” depending on the orientation).
If you look to the South, you will spot the instantly recognisable Orion constellation in all its glory. Pay particular attention to his sword where you might be able to see (you’ll need your binoculars for this one) the Orion Nebula – a star-forming region of gas and dust.
Also worth a note is the bright star Aldebaran – the eye of Taurus the bull- to be found near Orion.
And let us not forget what is perhaps the most important object in the night sky in the month of December……if you’re lucky, really lucky, and you look up after the sun has set on the 24th December…well maybe you’ll see a bright light streak across the sky and the faint jingle of bells as it passes overhead….