This Month’s Sky – December 2015

What’s Up in the Sky
AAA Observers’ December Guide
By Tony Faddoul

December’s Evening Planets:

Neptune is in Aquarius the Water Bearer until 11 PM and setting earlier every night until 9 PM by the end of the month. Uranus is in Pisces the Fish until 2 AM and setting earlier until midnight by the end of the month. Jupiter will be between in Leo the Lion and Virgo the Virgin as of midnight rising earlier every night until 10 PM by the end of the month.


December’s Evening Stars:

Spot The Winter Triangle: Sirius, the brightest star viewed from Earth, in Canis Major the Great Dog, Betelgeuse in Orion the Hunter, and Procyon in Canis Minor the Small Dog as of 8 PM. Find Castor and Pollux in Gemini the Twins, Rigel in Orion, Aldeberan in Taurus the Bull, and bright Capella in Auriga the Charioteer. See the stars of constellations Andromeda, Cassiopeia, Perseus, Cepheus, Draco, Aries, Taurus, and Ursa Major and Ursa Minor (the Big and Little Dippers).


December’s Morning Planets:

Find bright Venus between Virgo and Libra the Balance around 4 AM until sunrise. Mars will be in Virgo, and Jupiter will be between Leo and Virgo until sunrise. Mercury is in Sagittarius the Archer around 5 PM for about one hour during the second half of December. Saturn will be in Scorpio the Scorpion for one hour before sunrise in the second half of the month.


December’s Morning Stars:

The Winter Triangle of Sirius, Betelgeuse, and Procyon will be up until morning. Find Capella in Auriga, Arcturus in Boötes the Herds-man, Spica in Virgo, and Aldeberan in Taurus until the morning. See the stars of Leo, Gemini, Orion, Cassiopeia, Cepheus, Draco, Perseus, Ursa Major, and Ursa Minor.


December Skylights

Dec 3   Last Quarter Moon at 2:40 AM

Dec 5   Moon at apogee (251,530 miles away)

Dec11  New Moon at 5:30 AM

Dec 14 Geminid meteor shower peaks, pre-dawn

Dec 18 First Quarter Moon at 10:14 AM

Dec 21 Winter Solstice 11:49 PM

Dec 21 Moon at perigee (228,920 miles away)

Dec 25 Full Moon at 6:11 AM

Dec 31 Moon next to bright Jupiter (pre-dawn)


Geminids 2015 Peaks with  Hundred Shooting Stars Every Hour

The Geminid Meteor Shower is one of the most stable shooting star events each year. This year, it peaks on a moonless December night and will provide a spectacular show of about a hundred meteors per hour.


When is the Peak?

The Geminids will peak in the early hours of Dec 14. The best viewing window is late night on Dec 13 until morning twilight. Under perfect conditions (clear, dark skies), you’ll be able to view over 100 shooting stars every hour at the peak. The nights before and after will have similar numbers of visible meteors. The moon will set before mid-night, allowing for a perfect show.

Who can see the Geminids?

This bright meteor shower favors the skies of the northern hemisphere. Those who live further south will see fewer meteors. The southern hemisphere can see about 25 meteors per hour at peak under dark skies.


Colorful Geminids?

Geminids have a multi-colored meteors display – Approximately  65% being white, 25% yellow, and the remaining 10% blue, red and green.

How do I view the meteor shower?

Looking north to northeast, the meteors will seem to originate from the constellation Gemini, but you don’t need to locate their radiant – the Geminids appear to strike every-where across the sky. Find a dark spot, as far away as possible from light pollution, and hope for clear skies. There is no need for any equipment. Just look up, and enjoy.

Geminids in Greek Mythology

Castor and Pollux were the twin sons of Tyndareus and Leda, King and Queen of Sparta. Castor was a mortal, but Pollux was a demigod. He was the result of a union between Leda and the god Zeus, who disguised himself as swan one night.

Pollux was a fighter, and Castor was a horseman who were among the heroes who sailed with Jason and the Argonauts. Extraordinarily brave, they were inseparable and always fought as a team. One day, they got into a quarrel and Castor was killed.

Devastated by his brother’s death, Pollux was offered a choice by Zeus to keep his immortality or share it with Castor and save him. He chose the latter, and Zeus placed them together forever in the sky as stars. You can see the constellation Gemini manly during fall and winter.