Winter Sun

Jan 7, 2013

Do you know when the Earth is nearest the sun?  It’s January 4th, during what is typically the coldest part of our winter.   Seasons are caused by the tilt of the Earth’s rotation axis, not by our distance from the sun.

When the northern hemisphere is tilted away from the sun in late December and January we experience deep winter, while the southern hemisphere is tilted toward the sun and experiencing summer. 

From January 4th through the 17th the night sky is relatively dark, because the moon is between last and first quarter.  On January 11th the dark, new moon is near the sun and invisible to us.  But at 5:45 PM on January 12, a thin crescent moon will appear just to the right of ruddy-colored Mars in the southwest. On the next night, the 13th, the waxing lunar crescent will stand directly above Mars.

Because the moon is dark at this time, we can see the winter stars and constellations in all their splendor.  If you look east in the early evening, you’ll see the bright stars of constellation Orion rising, including reddish Betelguese and blue-white Rigel. 

High in the eastern sky stands the planet Jupiter, the largest planet in our solar system and the brightest object in early January’s evening sky, except for the moon during January 12th to 17th.   For the past several months, Jupiter has been moving through the constellation Taurus, the bull, which features the bright orange star, Aldebaran and two famous star clusters, the Hyades and the Pleiades.  This month, the Hyades can be found between Aldebaran and Jupiter.  The Pleiades cluster, also called the “7 Sisters”, stands above Jupiter. 

Western Slope Skies is produced by members of the Black Canyon Astronomical Society and KVNF.