Bakersfield Night Sky – December 19, 2009
By Nick Strobel
The early evening sky on December 19th offers a pretty sight of the thin Waxing Crescent Moon between very bright Jupiter on the left and a bright Mercury on the right low in the southwest. Mercury will be visible up to about 45 minutes after sunset for another few days and then it will move swiftly back into the glare of the Sun. The first star chart below shows the view for the next couple of days as well.
As Jupiter sets in the southwest at about 9 PM, turn around to see bright orange Mars rising in the east between the dim zodiac constellation of Cancer and the brighter Leo. The second star chart below shows this view. Mars has been slowing down its usual eastward drift among the stars and will stop on December 21st and begin drifting westward in its retrograde motion. This happens as we catch up to Mars in our faster orbit. We will pass next to Mars at the end of January but it will not be as close an approach as we have had the previous two times. The late evening sky also shows a number of bright winter constellations in the east. To the right of Mars, the first bright star you come to is Procyon in Canis Minor (the little dog). Further to the right in the southeast is Sirius in Canis Major. Sirius will be the only star brighter than Mars. Above bright Sirius will be Orion and further up is Taurus (the Bull) with the beautiful star cluster, the Pleiades at his shoulder. Those of you with eyes like mine will see the Pleiades as a fuzzy patch but those with better eyes will be able to count six stars in the cluster. To the left of the Pleaides will be the bright star Capella in Auriga. Below Auriga and to the left of Orion is Gemini with the two bright stars, Pollux and Castor on the left end.
Early risers will be able to see Saturn in the east on the right side of Virgo. Saturn rises at about 1 AM. The third star chart below shows the view at 5 AM. Mars will be high in the southwest and Saturn will be high in the southeast with the bright star Regulus of Leo in between them. The bright star Spica will be to the lower left of Saturn on the lower left corner of Virgo.
Winter officially begins when the Sun stops its southward drift among the stars on December 21st—the winter solstice. Even more precisely, the solstice occurs at 9:47 AM Pacific Time. While this day marks the shortest period of daylight for us, it is not the earliest sunset. That occurred in the first week of December. The reason why there is a mismatch on the dates of these two events has to do with the constant pace of our timekeeping devices in contrast with the more variable motion of the Sun in what is called the "Equation of Time". Do a search for "Equation of Time" on my Astronomy Notes website at www.astronomynotes.com for more details about that. (It takes a bit more space than I have available for this column to explain it!)
I hope you all have a blessed, safe, and joyous holiday season!
Want to see more of the
stars at night and save energy? Shield your lights so that the light
only goes down toward the ground. See www.darksky.org for how.
Director of the William M Thomas Planetarium at Bakersfield College
Author of the award-winning website www.astronomynotes.com
last updated: December 11, 2009
Webpage contact: Nick Strobel