The red Planet Mars is this years ‘Christmas Star’, shinning at its most brightest for two years. On the 8th of this month it disappears behind the full Moon for an hour. We have all the planets visible during the evening this month.
The Plough is now standing on its handle in the north. Capella, the bright yellow star, is not yet at the overhead point but it is very high up and cannot be missed. The twins of Gemini, Castor and Pollux, are much higher. Now is a great time to look for the Pleiades, or Seven Sisters, which are in the sky, looking south. This is a cluster of stars moving through space together. If you have good eyesight it is easy to see the seven brightest members of the Pleiades, using binoculars or a telescope however you would discover that there are actually about two hundred and fifty stars in the cluster.
The regular constellations of winter, Orion, with his two hunting dog Canis Major and Canis Minor dominate in the south. Leading the way for Orion is Taurus. Dominated by the red star Aldebaran. Auriga the charioteer is almost overhead
Of the summer triangle Altair is no longer visible, Vega is very low in the sky, and Deneb can still be found in the north west.
The planets :-
MERCURY
For most of December you will find the innermost planet to the upper left of very bright Venus, and twenty times fainter; so it will be best seen using binoculars. The innermost planet will be at its greatest separation from the Sun on the 21st of the month. Shinning at magnitude –0.5 it sets about 5pm.
VENUS
This month Venus has another long reign as the evening star, located low in the south west in the constellation of Sagittarius, just after sunset. By the end of the month, Venus blazes at magnitude -3.9 and falls below the horizon around 5.30pm.
MARS
The red planet is visible all night long. On the 1st of this month it is at it’s closest to the Earth. A week later it is lying opposite the Sun. On that same date Mars reaches its maximum brilliance at magnitude –1.9, and will almost be rivalling Jupiter. On the morning of 8th December the red planet reaches opposition at 4.24am, just 15mi9nutes after the full Moon. So the Sun, Moon and Mars are almost exactly in line. Then the Moon moves right in front of Mars, in another rare planetary occultation. Mars disappears about 4.55am and re-emerges around 5.55am. It’s the first occultation visible from the British Isles since 1952. The next will be in 2052.
JUPITER
The gas giant is the brightest planet after Venus has disappeared below the horizon just after midnight. At magnitude –2.5, it is located in the eastern sky in the constellation of Pisces.
SATURN
Saturn can be located low in the south west after sunset. At magnitude +0.8 it is lying in the constellation of Sagittarius. At falls below the horizon around 8.30pm.
URANUS
Dim Uranus is shinning at magnitude +5.7. It is just visible with the naked eye, but binoculars will help you find this distant world in the constellation of Aries. It will above the horizon until around 4.30am. On the 5th of this month between 4.50pm and 5.20pm the almost full moon moves in front of Uranus. Have a look with binoculars or a low power telescope.
NEPTUNE
You will need good binoculars or a telescope to spot this distant faint dot. At magnitude +7.9 Neptune lies in the constellation of Aquarius, and will fall below the horizon around 11.30pm.
PLUTO
This distant planet can be observed in a ten-inch or larger telescope. It can be found in the constellation of Sagittarius, with a magnitude +14.5 and is visible all night long.
CERES
The dwarf planet and largest body in the asteroid belt can be found in the constellation of Virgo. It shines at magnitude +8.4 and rises above the horizon around 11.40pm.
Special events:-
21st December at 9.47pm it is the winter solstice, the shortest day and the longest night.
Meteor showers:-
During the course of the night of 13th into the early hours of the 14th of this month, will be the maximum of the spectacular Geminid meteor shower. When the Earth hits a stream of interplanetary debris from the asteroid Phaethon. 100 meteors per hour might be observed from around 10 pm onwards. As the grains of dust are from an asteroid they are slightly larger than those from a comet, so the Geminids can produce many bright white coloured fireballs in the sky. Look up in any direction and you might be lucky to see at least one Geminid. This year, the Geminid meteor shower will be washed out by bright moonlight on the shower’s peak in the morning of the 14th. Try watching from late night until the moon rises. You might also catch meteors in moonlight.
Phases of the Moon for December:-
December 8th – Full Moon
December 16th – Last Quarter
December 23rd – New Moon
December 30th – First Quarter
Occultation of Mars, a full moon, and Mars at opposition 8th December