Mercury says goodbye to the year 2022 in the evening sky: the nimble planet reaches its greatest eastern elongation on December 21. From about the middle of the month, it can be detected deep above the southwest horizon at dusk. The best time for this is just before Christmas: on Christmas Eve, Mercury is -0.3 mag bright, at 17 o'clock CET, when the sun has sunk six degrees below the horizon and the civil twilight ends, 5.5 degrees above the horizon. That's not much: haze-free skies and binoculars help a lot with the sighting. On the following evenings, Venus, which is much brighter at -3.9 mag, will also be added: on December 24, it will still be located a good four degrees to the west and thus lower than Mercury. By the 29th of the month, the two planets are getting closer and closer and finally getting close to 1.5 degrees – Venus will then stand to our left below Mercury. They then switch their roles: Mercury sinks towards the horizon, while Venus gains altitude and its evening visibility begins.
Venus was in the Upper Konjunction on October 22nd. It moves east from the sun and begins its evening visibility in mid -December, which will last until July 2023 and will reach its peak in early May of next year. It slowly rises from the horizon haze and reaches almost five degrees on New Year's Eve shortly after 5 p.m., then standing almost four degrees southeast of Merkur. Venus is - 3,9 Mag Hell - but it is too early for telescopic observations (see "Pearl chain with a sized").
Mars is in opposition on December 8 in the constellation Taurus. Just on the opposition Day, more precisely on the morning of December 8, there is a rare occultation of the planet by the full moon: calculated for 50 degrees north and 10 degrees east, the Moon covers the planet at 06:03 CET and releases it again at 06:59. It is best to watch the event with a telescope at high magnification, but the occultation can also be tracked with the naked eye or binoculars (see "Moon swallows Red Planets"). In order not to be surprised by the exit, it is recommended to have the telescope tracked to the Martian position (if automatic tracking is available) while the planet is hiding behind the Moon. Thanks to its declination of 25 degrees north, Mars culminates at this opposition at an altitude of 65 degrees. This increases the chance of calm air – ideal for observation in a telescope with high magnification. Dark albedo structures, bright polar caps and possibly Martian weather phenomena are to be tracked: the albedo structures are areas of lower reflectivity, in which the red Martian dust reveals the view of darker rock layers. The bright polar caps are made of water and carbon dioxide ice. The same day-and-night, that is, the northern beginning of spring on Mars, falls on December 26. That's why we're getting a good look at both marshemispheres this year. After the southern summer, the southern polar cap should be small, the northern one, on the contrary, could be covered by an ice fog, the polar cap. Because of its eccentric orbit, the Red Planet reaches its approach to Earth already on December 1. The neighbor is 0.55 astronomical units (81.46 million kilometers) away on this day. In the earthly sky, it appears to be a maximum of 17.2 arcseconds in size and shines as an unmistakably reddish, -1.9 like bright star between the bull horns.
Jupiter receives twice a visit from the moon in December (see "Planetary chain with a Trabant"). On December 1st and 2nd and on the 29th of the month, the increasing earth drabant passes the –2.4 like bright giant planets south. The encounters always take place in the evening sky: the first month, Jupiter goes under at 1:33 a.m., on New Year's Eve at 11:48 p.m. We find it high in the south after the end of the dusk. When looking through the telescope, the Jupiter disc shows about 40 archery seconds. Also in December, his cloud structures and the four large Jupiter monds Io, Europe, Ganymed and Kallisto can be observed.
Saturn appears half-high above the southwest horizon towards the end of dusk. The 0.8 mag bright ring planet is located in the constellation Capricorn (see »Planetary chain with Trabant«). Its sinking times are delayed in the monthly course from 21:50 to 20:08. This leaves only about one and a half hours at the end of the month to observe Saturn more than 10 degrees above the horizon: its time is coming to an end, it is approaching its conjunction position, which it will reach at the beginning of February.
Uranus, which was in opposition on November 9, can be seen for almost the entire night in December as a 5.7 mag bright asterisk in the constellation Aries, about 12.4 degrees southeast of Alpha Arietis (Hamal). Finding him requires a star map. Except on the evening of December 5 at about 17:38: then the 12.5–day-old waxing Moon is located right next to the inconspicuous planet - it even covers Uranus, and this is just three days before the Martian cover on the morning of December 8. Unlike the bright Mars, Uranus stands out next to the Moon only in the telescope. After all, the entrance takes place on the narrow, unlit side of the moon, so it should be easy to follow. The planet, which is only 3.8 arc seconds small, will be covered within about ten seconds. The exit at about 18:27 (calculated for the center of Germany) is much more difficult to see on the illuminated side of the moon. Uranus goes down on the morning of December 31 at 03:56.
Neptune declines through the Aquarius. The 7.7 Mag Hellen planet can be found in the neighboring fish with the help of the radiant jupiter and the 4.2 Mag Hellen Star Phi Aquarii: It is quite close to the center of the liability line between the objects. Its low speed in front of the star background and Jupiter Standstill at the end of November ensure this excess aid for the entire month. Neptune appears to 2.3 sheet seconds in the telescope. It goes under in the middle of the month around 2:00 a.m. CET.
