Mercury is too close to the Sun to be observable in December with superior conjunction on the 17th. It will reappear in the evening sky in mid-January. Venus is a brilliant -4.0 magnitude morning star rising in the southeast about 03h 30m on the 1st but not until 05h by the 31st. Moon below on the 6th.

Mars is in Gemini and above the horizon all night. It is at opposition on the 24th. It reaches a maximum brightness of -1.7 mag. Moon very close on the 23rd-24th (see below).

Jupiter is in conjunction with the Sun on the 23rd and will not be observable this month. Saturn is in Leo at 0.6 magnitude, stationary on the 20th, and rising by 21h by the 31st. Moon nearby on the 1st and 28th-29th. Uranus is 5.7 magnitude and in Aquarius, setting by 22h by the 31st. Moon nearby on the 16th. Neptune is 7.8 magnitude and in Capricornus setting by 20h by the 31st. Moon nearby on the 14th. Uranus and Neptune are not naked eye objects.

The Moon: last quarter 1d 13h, new 9d 18h, first quarter 17d 10h, full 24d 01h, last quarter 31d 08h. The Moon is at perigee, its closest to the Earth, on 22d 10h. Regulus very close by on the 27th-28th. The Moon passes through the Pleiades star cluster in Taurus on the night of the 21st-22nd between 21h and midnight. With the Moon near full, it may be necessary to use binoculars to see the stars.

The Earth: the winter solstice, when the Sun reaches its most southerly point over the Tropic of Capricorn, is on 22 06h. It is also the date on which the Sun makes its shortest arc across the southern sky and reaches its lowest noon altitude for the year.

London area, sunset: 1 Dec 15h 50m, 31 Dec 16h 00m, sunrise: 07h 45m, 08h 08m. Nautical twilight ends: 1 Dec 17h 15m 31 Dec 17h 20m, begins: 06h 25m, 06h 45m.

Edinburgh area, sunset: 1 Dec 15h 42m, 31 Dec 15h 45m, sunrise: 08h 20m, 08h 44m.

Nautical twilight ends: 1 Dec 17h 16m, 31 Dec 17h 22m, begins: 06h 45m, 07h 08m.

The Geminids meteor shower is probably the most reliable of the annual showers, with maximum numbers expected on the 13th-14th and 14th-15th. The meteors appear to radiate from near the bright star Castor (see chart) and with little interference from the Moon, 60-80 per hour may be seen. Gemini moves round to be high in the south, then southwest later in the night.

Comet C/2007 F1 (LONEOS) was a rather difficult 6th magnitude object as seen from the British Isles. It was in twilight until near the horizon and observation was further hindered by a waxing Moon and misty weather. In late October comet 17P Holmes suffered an outburst during which it brightened a hundred thousand times to become an easy naked-eye object in Perseus. At 2.4 magnitude on 30th October it had faded to 3rd mag by mid-November. In December it will be near the ‘l' in Algol (see chart) but unless there is another outburst, it may well be harder to see.

Mars becomes more conspicuous in December, at its closest to the Earth on the 18th at 88.2 million km. On the night of 23rd-24th the full Moon will be near Mars and between 03h and 04h it will pass behind the lower edge of the Moon as seen from the extreme north of Scotland, Orkney and Shetland. From the south of the British Isles closest approach will be about 04h.