Highlights for the December Night Sky

Brought to you by: Bob Haskins @ Waterville Estates

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 discover the night sky


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

Dusk and into the night

December starts with Saturn, Venus and Jupiter forming a straight line in the SW; with Saturn highest in the sky at dusk and Jupiter is close to the horizon. Toward the middle of the month Venus has overtaken Saturn and Jupiter has disappeared below the horizon. For the rest of December Venus steals the show, shinning brightly at magnitude -3.9 and climbing higher in the nighttime sky with Saturn drifting slowly toward the western horizon.

The winter solstice arrives on December 21st.This will be the shortest day for us in the northern hemisphere and the start of the long winter.


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 nights of December 13th and 14th the strong and reliable Geminid meteor shower will be visible. It will peak just before dawn on the 14th but 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 moon will not be a factor. The meteors 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 / Comment 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:

It’s entirely possible that in the next decade or so, you will see a headline telling you that NASA has found evidence for life in space. Would that news cause you to run screaming into the street? In 2020 Mars and Earth will be once again be relatively close to one another. To take advantage of this, space agencies will be sending robotic explorers toward the Red Planet. They will be on the hunt for life – dead or alive.

A discovery that Mars has, or had, life would be enormously significant. It would be evidence that life is a process that begins on many worlds and consequently that the universe is brimming with biology.


Astronomy Websites to explore:

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