To make the firmament interesting there will be the Geminids, shooting stars equal in intensity to the Perseids. The shortest day of the year will be the 21st of the month.
This December will be a very interesting month for astronomy enthusiasts. Between eclipses of the Sun, the return of Mercury, the Geminids and the shortest day of the year that coincides with the winter solstice, it is worth marking in the agenda some appointments to look at the firmament. It is the Union of Italian Astrophiles to report that the day when there will be more hours of darkness, this year, will not arrive on December 13, as is commonly believed but the 21 of the month. To give show are also the giant planets and you can see the winter constellations.
The solar eclipse, the Geminids and the solstice
The total eclipse of the Sun was on December 4 but not visible from Italy. Only those who were in Antarctica were able to witness the event in its entirety. Partially observed also in South Africa and in the Atlantic Ocean. On December 13, the sky will shine with the Geminids, shooting stars comparable in intensity to the Perseids of August. If for the first two weeks of the month the sunset will remain constant between 16:40 and 16:41, on December 21 the Sun will set three minutes later but will rise 6 minutes later. So the shortest day of the year will coincide with the solstice that will welcome winter.
Mercury, Venus and other appointments
In the December evening sky Mercury will reappear. The most suitable conditions for observing it will be at the end of the month when it will set about 1 hour and 20 minutes after the Sun. On December 29 it will be easier to spot it thanks to the conjunction of Venus. An event that does not happen very often and that can be seen during the month is the passage of the giant planets from one constellation to another, for example Jupiter will leave Capricorn on December 14 to enter Aquarius.
From December 7, for a few days, the crescent Moon will align with three planets. On this evening Venus will be visible in Sagittarius, followed by our satellite, Saturn and Jupiter in the constellation of Capricorn. On December 8, the order changes with Venus remaining in the lead and will be the first to set, then Saturn, the Moon and Jupiter. On December 9, the Moon will reach Aquarius overtaking Jupiter, Saturn and Venus.
Always in the first part of the month you can also admire some light transits of the International Space Station and December will be the best month to observe the great winter constellations such as Orion, Cane Major, Taurus and Gemini. You will be able to admire some of the brightest stars such as Sirius, Aldebaran, Castor and Pollux.