A sparkling end to the year: starry skies in December
All the planets of our solar system in one night, sparkling shooting stars and brightly shining winter stars within reach
The longest night of the year is coming up: On 21 December at 4:58 pm is the winter solstice: On this day it is only light for a little more than 8 hours. The night of 22 December, on the other hand, will last almost 16 hours - 12 of which will be pitch dark. Astronomers and stargazers will thus have plenty of time for extensive observations of the magnificent winter constellations - and planets!
Yes, that's right: In December, all the planets of our solar system can finally be observed in the sky again, because Mars reappears. On top of that, it seems to rain stars from St. Nicholas on.
All details about the nightly December sky as well as information about worthwhile deep sky observing objects can be found in our Sky Guide for December 2021. But we already give you an overview here:
Moon near Earth - total solar eclipse in parts of the southern hemisphere
December begins with dark new moon nights - on 4 December the moon changes to the new moon. And not only that: on this day, at a distance of 356 800 kilometres, it reaches its shortest distance to Earth in the entire year. At the same time, the moon moves in front of the sun - but the total solar eclipse on 4 December can only be experienced in the deep south of the southern hemisphere.
A comet for Advent?
Now the best visibility phase for comet C/2021 A1 (Leonard) begins. It is currently visible in the second half of the night, moving out of the constellation of Hunting Dogs towards Boötes. On 4 December it passes the bright star cluster M3 on its orbit and then continues to pass the star Arcturus day by day towards the horizon. Depending on the brightness development, it can also be found in the first half of December in the evening after sunset low in the west. The brightness forecasts are still uncertain at present. Whether Leonhard will be a comet for the naked eye is unclear. However, with binoculars or a small telescope it should definitely be reachable in good conditions.
Celestial lights in the evening from Venus, Saturn, Jupiter and Mercury
In our latitudes, you will have the best view of evening star Venus for this on December 4, which shines conspicuously in the southwestern sky just after sunset until about 7:00 pm. Enjoy it, as it sets earlier and earlier as the month progresses: An indication that Venus will soon bid farewell to the night sky as the evening star.
The planetary duo Saturn and Jupiter are also preparing their (temporary) departure from the celestial stage. Shortly after Venus has peeled out of twilight, giant planet Jupiter appears about three and a half handbreadths to the left above Venus. When it is really dark around half past five, you can then also make out ringed planet Saturn, about halfway between Jupiter and Venus. On the nights around the new moon, you can observe Saturn until eight o'clock, Jupiter until about 10 o'clock in the evening. This changes by the end of December: the two planets set earlier and earlier. On New Year's Eve, Saturn sinks below the western horizon before 7 p.m., followed by Jupiter shortly before 9 p.m.
In exchange, Mercury appears in the evening sky at the turn of the year. Starting on 28 December, you can spot the rare guest two fingerbreadths below Venus at 5:00 pm with the help of fast binoculars. But be quick: on this evening Mercury is only visible for a quarter of an hour. In the following evenings it rises a little higher and remains visible for a few minutes longer. However, the overall visibility remains modest and on 13 January Mercury disappears from the scene again.
Neptune and Uranus for experienced observers
For experienced observers, the evening sky in December still holds a duo of planets: The two gas giants Neptune and Uranus. From a quarter past six in the evening, Neptune is high in the south. But you need either very good binoculars or (even better) a telescope to see it. With Uranus, which replaces Neptune high in the south from about half past eight in the evening, you might be lucky to spot it with the naked eye under ideal conditions (very dark, clear nights). However, both planets are so far away from Earth that even with a good telescope they are only visible as small discs.
Back again: Mars in the morning sky
After an absence of half a year, Mars finally shows itself in the firmament again from mid-December. Admittedly, it first needs very favourable conditions, i.e. a clear horizon, and it's best to grab a pair of binoculars to start with, because Mars is not yet particularly bright in December. But around seven o'clock in the morning you can just catch a glimpse of the planet standing low in the northeast before dawn becomes too bright. In the coming year Mars will then increase in brightness and by the end of 2022, as in 2020, it will be a very conspicuous celestial star.
Small tip: Look for the narrow crescent moon on New Year's Eve. A little to the left below it, you can make out the soft red shimmering Mars.
Mars at Antares
And speaking of "dates": Make a note of Boxing Day. For on 26 December Mars passes by the also reddish shimmering Antares, main star in Scorpio. Antares is even a little brighter than our neighbouring planet.
Many wishes granted: showers of shooting stars after Nicholas
At mid-month - between 6 and 16 December - the Geminid shooting star stream lights up the long December nights. The meteors seem to come from the constellation Gemini and dart from there in all directions. We expect the highest rate of fall, with up to 120 per night, from 13 to 14 December. Every two to three minutes, provided the sky is clear, you should be able to spot a shooting star. Romantics should not forget to make a wish: According to folklore, these wishes come true.
Sparkling Winter Stars: Within Reach
When it gets dark in the evening, the winter images have already all paraded in the eastern sky. Unmissable and easy to recognise by its three prominent belt stars: Skyhunter Orion. Just below its belt stars, on clear, dry nights, the Orion Nebula can be seen shimmering a delicate blue with the naked eye. This huge cloud of dust and gas is something like a celestial nursery, because young stars only a few million years old are embedded in it.
Orion's right foot star, the blue-white shimmering Rigel, then also forms one of the six corners of the famous winter hexagon. The other five corners are formed by the yellowish shining Capella in the Wagoner, the red Aldebaran in Taurus, the bright and sparkling Sirius in the Great Dog, Prokyon in the Lesser Dog and Pollux in the Twins.
Did you know that Sirius and also Prokyon are within reach of Earth in cosmic dimensions? Sirius is just 8.7 light years away from us, Prokyon 11. Giant star Rigel, on the other hand, is a whole 1500 light years away - but due to its size, this young star emits so much light that it nevertheless stands radiantly bright in the firmament.
We think there can hardly be a more sparkling end to the year. We wish you a Merry Christmas and a Happy New Year.