EYES ON THE NIGHT SKY - DECEMBER 2020
Welcome to the latest edition of Eyes on the Night Sky, where we will select the best night sky events for December. This is going to be a great month for major astronomical events so wrap up warm, grab a hot drink and get outside!
As the Perseid Meteor Shower was a washout this year due to the presence of the Moon, there will be a second chance to see 'shooting stars'. The Geminid Meteor shower will peak during the late hours of 13th December and early morning of 14th December.
There will be a New Moon at this time so it will be an ideal time to spot some fantastic ‘shooting stars’ which will be colourful; caused by the presence of sodium and calcium in the debris of asteroid 3200 Pantheon. In a very dark sky, away from light pollution, you may spot up to 100 meteors an hour; however, light pollution may affect the visibility of these moderately fast meteors.
The New Moon falls on 14th December and the Full Moon on 30th December.
If you have access to a good south- western horizon, you will be in for a rare treat. On 21st December, there will be a great conjunction of Saturn and Jupiter that occurs once every 20 years. A great conjunction occurs when two of the largest planets in the solar system appear to pass close to each other from our viewpoint, in this case, only 0.1 degrees distance, which is about 20% of the width of a full moon. The last time such a close conjunction occurred, Galileo Galilei, the ‘father of modern astronomy’ who lived 400 years ago, was alive. Just after sunset, look to the low western horizon and look for a bright star emerging into the dusk, which will be the two planets. It will look spectacular with the unaided eye but binoculars will separate the planets within the field of view.
If you have a small telescope, the views will look incredible, with both Saturn and Jupiter appearing in the same field of view, with Saturn’s rings and Jupiter’s cloud bands, including all the moons of both planets. As this great conjunction is quite low to the horizon, atmospheric turbulence might cause issues with detail but this is a rare event not to be missed! Anyone blessed with an abundance of clear skies can observe how the two planets draw closer to each other and move apart in their nightly dance over December.
Here’s an asterism in a popular star cluster you might not have noticed! Ally’s Braid is an asterism comprising seven stars in the shape of a loose ‘V’and can be seen with binoculars.
It lies in the heart of the stunning Pleiades Cluster and good observing skills might even be able to spot it in a moderately light polluted sky.
We were able to spot it during first quarter phase of the Moon (53%) with 10x50 binoculars.
Constellation of the Month – Auriga
This constellation is often missed among the more recognisable ones in the winter sky. Auriga lies north-west of the constellation of Orion, with the constellations Gemini and Taurus as its neighbours. There are a few very nice star clusters within the constellation: Messiers 36, 37 (which can be seen with the unaided eye in dark skies) and 38. Use your telescope or binoculars to spot them.
Auriga represents a charioteer who holds a nanny goat, her kids and the reins of a chariot. In fact, the word Auriga is Latin for ‘Charioteer’ and the shape of the constellation is meant to represent the hat that is worn by someone in that profession. The best way to spot this constellation is to look for the Pleiades Star Cluster and form a triangle with Betelgeuse in Orion – look directly upwards from the star and the next brightest star is Capella in the constellation of Auriga. Capella is the sixth brightest star in the northern hemisphere. The constellation is also directly opposite to the core of the Milky Way Galaxy, situated around the constellation of Saggitarius. You cannot see the Core but look towards Saggitarius in the summer and feel amazed that the centre of our galaxy is a staggering 25,300 light years away!
Greek Mythology identifies the constellation or Auriga with the charioteer Myrtilus, the son of Hermes. He took place in a chariot race in an attempt to win the hand of the beautiful Hippodmia, the daughter of Oenomaus. Her father took part in the chariot race and would kill any contestants he caught up with. Myrtilus drove the king’s chariot which meant that the other contestants couldn’t win the race until Pelops fell in love with the king’s daughter. Hippodamia persuaded Myrtilus to tamper with the wheels of her father’s chariot so that Pelops would win. Myrtilus succeeded in his mission and Pelops won the hand of Hippoamia. However, Pelops decided to throw Myrtilus into the sea and Hermes, his grieving father, placed his son’s image among the stars. It is not known why a nanny goat is seen on the shoulder of Myrtilus but she is represented by the star Capella, which is Latin for ‘She-Goat’.
We hope you get some time during the festivities to get outside and look up. Have a lovely Christmas and hope that 2021 is a better year for all of us!