Photo of the Week.. Dramatic sunset with glitter
path.
Astronomy news for the two weeks starting Friday, December 16,
2016.
The next skylights will appear December 30, 2016. Best wishes for the Holiday Season.
We end 2016 with the Moon running through its late waning phases,
beginning with the waning gibbous, which ends at third quarter on
Tuesday, December 20, nine hours before the Sun hits the the Winter Solstice. It then
glides through its waning crescent
phase until it hits new Moon on Thursday the 29th. Your last view of the
waning crescent will be the morning of Tuesday the 27th with Saturn to
the northwest of it. The Moon will appear to the west of Jupiter
the morning or Tuesday the 22nd, to the other side the following
night.
The big event is the passage of the Sun over the Winter Solstice at 4:44 AM CST (5:44 EST, 2:44 PST) on
Wednesday the 21st, giving us he shortest day and longest night in the
northern hemisphere. The Sun will rise as far to the southeast and set
as far to the southwest as possible for any given latitude. Because of
the tilt of the Earth's axis and the eccentricity of its orbit, we've
already passed the time of earliest sunset, which took place on December
7, and you'll quickly see the evenings getting lighter.
Venus glows brilliantly in the southwest, You can't miss it. Mercury,
though, goes through inferior conjunction with the Sun on Wednesday the
28th and is quite invisible. Mars still reliably
sets in the southwest at 9:30 PM. Of lesser significance, Uranus ceases
retrograde (westerly) motion on Thursday the 29th. The Moon goes through
apogee, where is it farthest from Earth, on Christmas Eve.
It's Jupiter, however, that dominates much of the night, rising at 1 AM
as the year comes to an end, an hour later as we open our period. Saturn
remains in morning twilight.
With some luck you might see a few meteors from the underappreciated
Ursid meteor shower, which peaks the morning of Wednesday the 22nd and
appears to come from Ursa Minor - the
Little Dipper - which is always nearly due north.
The Great Square of Pegasus and its
attendant autumn constellations move off
to the west to be replaced by those of winter. With the Sun at the
Winter Solstice, you'll see the Summer
Solstice, on the Gemini-Taurus border, high at midnight. Below will
be mighty Orion with his three-star Belt and Canis Major, which holds Sirius, the brightest star of the sky.