Science

The Sky Above You – December 2021

By Duncan Lunan

The Moon will be New on December 4th, and Full on December 19th, two days before the winter solstice, when it will be near Castor and Pollux in Gemini.  On the night of the New Moon there will be a total solar eclipse, visible only from Antarctica.  The crescent Moon will be near Venus on the 7th and 8th , and before First Quarter, the Moon will be near Jupiter on the 9th.   On the 16th and 17th  the Moon will be near the Pleiades and Hyades clusters, and Aldebaran, the brightest star in Taurus.  On the morning of December 31st, the waning crescent Moon will be at upper right of Mars. 

The planet Mercury was at superior conjunction on November 29th and will be invisible for most of December, appearing low and faint in the evening sky at the end of the month, below Venus and setting at the same time.  Venus and Mercury will be closest on December 29th, when they will be level in height near the horizon.

Venus remains low in the southwest, in Sagittarius, setting at 6.30 p.m., with the Moon nearby on the 7th and 8th, setting at 5.20 p.m. by the end of December, with Mercury appearing below and rising in the last few days to draw level..   

Mars rises at 6  a.m., in Libra, moving on into Scorpius and Ophiucus, passing above its rival Antares in Scorpius on the 27th and 28th, and passed by the Moon on the mornings of the 3rd and 31st.

Jupiter in Capricornus sets at 9 p.m. , and is passed by the Moon on the 9th.  

Saturn, also in Capricornus, to the right of Jupiter and much fainter, sets at 7.30 p.m. and is passed by the Moon on the  8th.

Uranus in Aries sets at 4.30 a.m..  Uranus is near the Moon on the 15th.

Neptune in Aquarius sets at 11.30 p.m., near the Moon on the 11th

The Geminid meteor shower from the mysterious asteroid Phaeton  (the only one of its kind) begins on December 3rd and peaks on the night of December 13th/14th,  and will be best seen after midnight, once the Moon is down. 

Comets

As it happens, there are four comets in the December sky;  and four articles on comets coming up in the ‘Beginners’ Astronomy’ column on Sundays, which will take us to the end of the year;  and one of the four December comets will be covered in detail there.  As its number indicates, Comet 19P/Borelly is a well-known periodic comet, while Comet 2019 L3 ATLAS is a much more recent discovery, and neither of them will be bright enough to be seen without a telescope.  Comet Leonard  (2021 A1)  will be visible with binoculars and might just reach naked-eye visibility, though it will be hard to find from this far north because it will be disappearing into the southern sky and the morning sky by mid-month.   (For maps see the December issue of Astronomy Now, pages 44-45.)  The greatest scientific interest will probably be in Comet 67P/Churyumov-Gerasimenko, which will be at perihelion  (its closest to the Sun) for the first time since the prolonged study of it by Europe’s Rosetta spacecraft in 2014-2016.  Despite the limited success of the Philae lander, so much was learned from that mission that a return to the comet is now under serious consideration.  

There is no meeting of the Astronomers of the Future Club in December.  On November 24th, the guest speaker was Matjaz Vidmar of the University of Edinburgh, on ‘How Space Affects Our Lives’, and the January 2022 subject has still to be announced.  The AOTF Club has been awarded a grant from Troon Round Table, which will allow us to invite more guest speakers next year, and we already have some very interesting possibilities.  For more information, contact Alan Martin on 07947-331632.

Duncan Lunan’s most recent book, The Other Side of the Interface, was published by Other Side Books at the beginning of the year, and is available through Amazon or through bookshops, or from the publishers.  For details and for his other books see Duncan’s website, www.duncanlunan.com.

You can download a copy of the star map here: