Highlights for the December Night Sky

By Bob Haskins

Do your part and help preserve the dark skies that we are fortunate to have

in Waterville Estates. Turn off all unnecessary outdoor lighting

Go outside tonight and be a stargazer


The Planets: “Evenings on the Ecliptic” The planets all follow an imaginary path in the sky called the ecliptic.

            This month is a total loss if you want to spot a planet in the nightime sky. There are none at all. Hopefully next month will be better.

            Jupiter and Mars: Mars rises at the same time in the cold pre-dawn hours all month.  Jupiter scurries to catch up with Mars as December progresses. As the year comes to a close the two planets peek above the horizon at the same time in the early morning.

            Venus and Mercury: Both planets are no shows all month, lost in the glare of the Sun.


Stars and Constellations:

            The cycle of the seasons is almost complete. The summer constellations are setting in the west just as the winter constellations are rising in the east. As the month progresses, Orion “The Hunter”, the most popular of the  winter constellations, rises in the east. In the northeast, the bright star “Capella”, which means the “goat”, shines brightly along with her three little companion stars which are referred to as her kids. They are part of the constellation Auriga  the “Charioteer”. Check out Capella with your binoculars to get a good view of the “kids” (refer to diagram). Also look to the north for Cassiopeia, upside down W” and the Big Dipper which should be near the horizon.

            Turn to the west and see the curtain coming down on the stars of the “Summer Triangle”. Vega and Altair are starting to disappear toward the horizon followed by Deneb.

            On the night of December 13th the strong and reliable Geminid meteor shower peaks. It should also be fairly active the night before and after. The Geminid shower is the richest and most reliable shower of the year, and it seems to have strengthen over the past years. The best viewing will be around 9 to10 pm. The moon will not be a factor this year like it was last year. The shower will be coming out of the northeast.

            The Winter Solstice arrives on December 21st. This is the longest night of the year in the Northern Hemisphere and marks the start of our winter. At this time, we in the north are leaning away from the Sun and the Sun has reached its southern most excursion on the ecliptic and is directly overhead at the Topic of Capricorn in the Southern Hemisphere. They are enjoying their longest day and it is the start of their summer. Many cultures in the Northern Hemisphere hold festivals of light to symbolize cheer and hope in this season of the shortest days.


Factoid of the Month:

Why does the moon always present the same face to us?

Our lunar companion rotates while it orbits the Earth. It’s just that the amount of time it takes the moon to compete a revolution on its axis is the same it takes to circle our planet – about 27 days. As a result, the same lunar hemisphere always faces Earth.


Astronomy News:

            We have a new neighbor, an earth size exoplanet just 11 light years away. This new-found world is the closest temperate planet know to obit a “quiet” star – You can trust it will not fry its own planet. So far a few dozen Earthlike planets have been found. However, scientists tell us that are possibly a million of them in our Milky Way galaxy alone.


Astronomy Websites to explore:

  • heavens-above.com (satellites that are passing overhead)
  • gov
  • com
  • nasa.gov (sign up for alerts for the International Space Station passing overhead in your area)
  • com (The evening sky map for the month)