To end 2021 there is a parade of planets after sunset and an impressive display of shooting stars, as well as the brilliant winter constellations.
The Plough is now standing on its handle in the north. Capella, the bright yellow star, is not yet at the overhead point but it is very high up and cannot be missed. The twins of Gemini, Castor and Pollux, are much higher. Now is a great time to look for the Pleiades, or Seven Sisters, which are in the sky, looking south. This is a cluster of stars moving through space together. If you have good eyesight it is easy to see the seven brightest members of the Pleiades, using binoculars or a telescope however you would discover that there are actually about two hundred and fifty stars in the cluster.
The regular constellations of winter, Orion, with his two hunting dog Canis Major and Canis Minor dominate in the south. Leading the way for Orion is Taurus. Dominated by the red star Aldebaran. Auriga the charioteer is almost overhead
Of the summer triangle Altair is no longer visible, Vega is very low in the sky, and Deneb can still be found in the north west.
The planets :-
In the south west sky there is a line of three bright planets. Venus to the right, Saturn in the middle and Jupiter on the left.
At the start of December, Venus is streaming towards the other two. Just after mid-month the Evening star changes direction and moves back downwards again.
Venus starts the month at magnitude –4.6. Peaking at a brilliant -4.7 on 7th December, when it forms a stunning duo, with the crescent Moon in the south west after sunset. But it fades to magnitude -4.3 by the end of December. Through a telescope, or even binoculars held steady, you will see Venus shrink dramatically to a narrow crescent.
At the start of the month the Evening star is setting at 6.30pm, but by the close of December it sinks below the horizon as early as 5.20pm.
During the last few weeks of December, you may catch Mercury to the lower left of Venus, setting at the same time and 30 times fainter at magnitude –0.7.
Saturn lies in Capricornus all month, shining at magnitude -0.7 and setting around 7.30pm.
It’s larger sibling Jupiter is at a magnificent magnitude –2.2, and sinks below the horizon about 9pm, moving from Capricornus to Aquarius around mid-month.
To the other side of Aquarius, dim Neptune glows at magnitude +7.9 and sets about 11.30pm.
Uranus at magnitude +5.7 lies in Aries and is setting around 4.30am.
In the morning sky you will find Mars low in the morning twilight. Rising in the south east at 6am and shinning at magnitude +1.6. During this month the Red planet moves from Libra through Scorpius and into Ophiuchus. On the morning of 27th and 28th of December, Mars passes above Antares. On the 31st of the month low in the south east, the narrow crescent Moon hangs to the upper right of Mars, with Antares below.
21st December at 3.59pm it is the winter solstice, the shortest day and the longest night.
Meteor showers:-
During the course of the night of 13th into the early hours of the 14th of this month, will be the maximum of the spectacular Geminid meteor shower. When the Earth hits a stream of interplanetary debris from the asteroid Phaethon. The best views will be in the small hours after the Moon has set. Around 100 meteors per hour might be observed from around 10 pm onwards. As the grains of dust are from an asteroid they are slightly larger than those from a comet, so the Geminids can produce many bright white coloured fireballs in the sky. Look up in any direction and you might be lucky to see at least one Geminid.
Phases of the Moon for December:-
December 4th – New Moon
December 11th – First Quarter
December 19th – Full Moon
December 27th – Last Quarter