December 2017

Your guide to the Night Sky during December 2017...

The elusive Mercury is briefly visible very low in the evening twilight for the first couple of nights in December, along with the ringed planet Saturn just a degree or so above Mercury. Both will be lost in the Sun’s glow very soon, although Mercury will be visible again later in December, although this time in the morning sky. At its highest, the planet will be only about 4 degrees above the ESE horizon at around 7am on the 29th Dec.

The Outer planets Uranus and Neptune are the only other bodies visible until the early morning hours, and these require binocular or telescopic aid to detect them. As you can see from the photos taken through one of my scopes, it is very easy to “overlook” these planets and assume that they are just “normal stars”. Only by comparing a sketch of the areas with a star map would the “intruders” become apparent, or by taking a couple of photo’s a few days apart and noting which “star” had moved during the time between shots.

As just mentioned, it’s the early morning hours before a couple of other planets become visible in the Eastern sky prior to Sunrise. Mars and Jupiter are starting to become prominent, with a thin crescent Moon lying between and above the pair on the 14th December. Venus, so long shining in the morning twilight has slipped back into the Sun’s glow, but will reappear in the evening skies next year.

Looking out for meteors this month, we have two showers coming to maxima, the Geminids on the 13-14th and the Ursids (Ursa Minor) on the 22nd.  Of the two, the Geminids are by far the more active shower with upto 100 per hour predicted and this year, the interfering Moon will be out of the way until around 3am. Prospects for the Ursids are even better with just a 4-day-old Moon around for a handful of hours after Sunset. This is a rather under observed shower, given the time of year I suspect, but can produce around 10 or so meteors per hour from a radiant that is visible all night. Again, keep your eyes open, as you just don’t know your luck.

To end the year, on the night of 30th- 31st December, the Moon again passes through the Hyades star cluster, which is really the “V” of Taurus. A number of bright stars will pass behind (or be occulted to use the correct term) during the night, including the brightest star in Taurus, the red Aldebaran.

Well, there you have it. Good luck, clear skies and all best wishes for Christmas and the New Year to you all.

Huge thank you to Les Fry for the December Night Sky information!!


Snowdonia National Park Authority