Mars
Best time to see: 1 December, 06:20 UT Altitude: 28º Location: Aquarius Direction: South Features: Polar caps, albedo markings, phase Equipment: 28-inch or larger
If there were ever an award for the most frustrating planet in the sky for UK observers, Mars would win it hands down. It reached a favourable opposition on 27 July of this year but from the UK this happened very low down in the south. This month, as the distance between Earth and the Red Planet increases, Mars starts to gain altitude – of course!
The increase in distance means that our view of Mars through a telescope now shows a much smaller disc – just 9 arcseconds across on 1 December, shrinking to just 7 arcseconds by the end of the month. Compared to the 24 arcseconds Mars presented back in July, it’s now looking rather small.
The Red Planet is currently an evening object in Aquarius. On 1 December it lies 2° southwest of mag. +3.7 Lambda (h) Aquarii and shines at mag. 0.0. It passes 40 arcminutes south of Lambda on the evening of 4 December as it heads towards a close encounter with Neptune on 6 and 7 December.
On 6 December, mag. +0.1 Mars lies 27 arcminutes west of mag. +7.9 Neptune.
The following evening the positions swap, Mars moving to a position 11 arcminutes east of Neptune. On 12 December, mag. +0.2 Mars lies 20 arcminutes from mag. +4.2 Phi ( ) Aquarii. A 43%-lit waxing crescent Moon sits near Mars on the evening of 14 December. On 22 December, mag. +0.3 Mars slips across the border from Aquarius into Pisces and by the end of the month, it can be seen moving south past the Circlet asterism. By the end of December its magnitude will have dropped to +0.5. This is when it manages to attain a maximum altitude, due south, of 36° (just over a third of the way up the sky from the horizon) as seen from the centre of the UK. This is 3.6 times higher than it managed at opposition!