December 2018

Sky Report - December 2018

By Dr. Bob Doyle, Emeritus Faculty
Dr. Doyle taught and was Planetarium Director at Frostburg State University for over 40 years

First Quarter of December (Dec 1-7)

Sunrises are at 7:19 a.m. with sunsets at 4:51 p.m. Daily sunlight lasts 9.5 hours. 4:51 p.m. is the year’s latest sunset which persists through December 15. Brilliant Venus will appear above and to the right of the crescent moon in the southeastern dawn on December 4. The moon’s motion about Earth will carry it from the morning to the evening side of the sun on December 7 (New Moon). The planet Mars in the southern evening sky will appear close to the dim planet Neptune on the evening of Friday, December 7. To see distant Neptune you will need a telescope to see this faint blue planet. Neptune appears blue because of the methane gas in its atmosphere which absorbs red and green sunlight. The bright winter evening stars are prominent in the evening sky (look at 8 p.m.). Look in the Southeast for Orion, a tilted rectangle with 3 stars in a row in the middle. On the upper left corner of the rectangle is Betelgeuse, a bright pinkish star. On the lower right corner is Rigel, a white-blue star and Orion’s brightest. Orion’s three stars in a row points up and rightward to Aldebaran, a bright orange star that marks the eye of Taurus, the Bull.

Second Quarter of December (Dec 8-15)

Sunrises are at 7:25 a.m. with sunsets at 4:51 p.m. Daily sunlight lasts 9.4 hours. The innermost planet Mercury joins brilliant Venus in the southeastern dawn with the dimmer Mercury below and to the left of Venus. The evening moon grows from a slender crescent on December 9th to half full (like a ‘D’) on December 15th. Along the left straight edge of the moon, the sun is rising, lighting up the raised crater rims and elevations. So these lunar features are best seen with a telescope in mid December. The Geminid meteor shower peaks in the morning hours of December 14. Dozens of meteors may be seen per hour. These meteors can be traced back to the star group Gemini to the left of the star group Orion. The morning hours are best as the meteors are colliding with the Earth head on and appear brighter. The planet Mars appears above the moon on the evening of December 14.

Third Quarter of December (Dec 16-23)

Sunrises are at 7:31 a.m with sunsets at 4:53 p.m. Daily sunlight is then a minimum for the year at 9 hours and 22 minutes. The planet Mercury appears near the bright planet Jupiter at dawn on December 21. On the evening of December 21, winter officially begins with the sun’s vertical rays reaching farthest South to latitude 23.5 degrees South (Tropic of Capricorn). Well known places near this line include Rio de Janeiro (in Brazil), the Kalahari Desert in Africa and the middle of Australia. The moon is full on the evening of December 22. This has been called the Long Night Moon, shining all through the long winter night (lasts over 14 hours). One notable evening sky sight is the Northern Cross (Cygnus) floating over the northeastern horizon. Below and to the right is the very bright star Vega, furiously twinkling near the horizon. The top star of the Northern Cross is Deneb, one of the most distant bright stars that is 1400 light years away. Below Deneb is the central star of the cross arm with stars to the left and to the right. At the bottom of the cross is Albireo, a beautiful double star through a telescope.

Last Quarter of December (Dec 24-31)

Sunrises are about 7:35 a.m. with sunsets about 4:58 p.m. Daily sunlight lasts 9 hours and 23 minutes. On New Year’s eve, we have the latest sunrise at 7:36 p.m., which lasts until January 10th. At 8 p.m. in the evening, Sirius, the brightest night star can be seen low in the East Southeast. Orion’s belt of three stars in a row points left and down to Sirius. Sirius’ brilliance is due to its close distance of 8.6 light years. Sirius is the bottom star of the Winter Triangle. The leftmost star of the Triangle is Orion’s pink star Betelgeuse. On the right side of the Triangle is Procyon, a neighbor star to Sirius at 11 light years from the Earth. Low in the North Northeast is the bowl of the Big Dipper. The top two bowl stars point up and left to the North Star, a modest star about halfway up in the North. The North Pole points to the North Star so as the Earth turns, all the stars in the North move counterclockwise around the North Star.

For a free copy of my 2019 Night Sky Highlights, send an email to rdoyle@frostburg.edu. This lists sunrise and sunset times for every Sunday, the moon-planet line ups and the moon’s main phases for 2019, all on 2 pages.