Your calendar probably says tomorrow (Tuesday, December 17) is the date for the last – and smallest – full moon of 2013. But, for North America, the full moon comes before sunrise tomorrow. So, for us, the moon turns full tonight. Need the exact time of full moon? It’s Tuesday, December 17 at 9:28 Universal Time (4:28 a.m. EST, 3:28 a.m. CST, 2:28 a.m. MST and 1:28 a.m. PST). Tonight, the moon shines in front of the constellation Taurus the Bull, in the vicinity of the Bull’s brightest star, Aldebaran.
Quite the opposite of a supermoon, tonight’s full moon ranks as the smallest full moon of the 2013. However, next month’s January 2014 full moon will be even smaller than the December 2013 full moon, to showcase the smallest full moon of 2014.
Day and night sides of Earth at instant of full moon
As always, the moon moves eastward in front of the backdrop stars (and planets) as its orbits our planet Earth. That eastward motion will bring the moon closer to the bright planet Jupiter on the evening of December 17 and, closer yet to the king planet on the evening of December 18. Watch for Jupiter to rise in the east at nightfall or early evening tonight and throughout December 2013.
Because this is the closest full moon to the December solstice, this moon carries the name Long Night Moon. That name works for the Northern Hemisphere, where the daylight is fleeting now, while the nighttime is long-lasting. In the Southern Hemisphere – where the days are long and the nights are short – perhaps we could call the closest full moon to the December solstice the Short Night Moon.
The full moon – as always – mimics the sun’s path for some six months hence. Watch tonight as the moon rises around sunset and sets around sunrise tomorrow. Around midnight, the moon climbs highest up for the night, mimicking the position of the June noonday sun.
Given clear skies, most everyone all around the world will see the moon shining from dusk until dawn tonight. In the Northern Hemisphere, the moon’s path across the sky tonight will resemble that of the high-flying summer sun. In the Southern Hemisphere, the moon’s path will follow the low arc of the winter sun.
Somewhat north of the Arctic Circle, there is no sunrise right now because the sun stays below the horizon. But the closest full moon to the December solstice stays out all night long at these far northern latitudes, playacting as the midnight sun of summer.
Somewhat south of the Antarctic Circle, the sun stays out for 24 hours around the clock. However, the closest full moon to the December solstice simulates the winter sun in the Southern Hemisphere. For that reason, this December full moon won’t rise above the horizon at these far southern latitudes.
By the way, tonight’s bright and round moon shines right in front of the great big star formation known as the Winter Circle. In the Southern Hemisphere, though, it should really be called the Summer Circle. Either way, tonight’s moon shows you where the sun will reside in front of the background stars six months from now.
Watch tonight, as the Northern Hemisphere’s Long Night Moon (Southern Hemisphere’s Short Night Moon) lights up the nighttime from dusk till dawn!