GARRETT COUNTY SKIES
By Dr. Bob Doyle, Frostburg State Planetarium
Moon Passes by Planets, Long Night Moon on the 13th, Mars – Neptune Line Up on 31st
SUN & MOON: At the start of December, Oakland sunrises are about 7:19 a.m. with sunrises about 4:55 p.m. for sunlight duration of 9 hours and 38 minutes. The sun is in the star group Ophiuchus till December 17 when it moves into Sagittarius. On December 21, winter begins with the sun’s vertical rays are furthest South, reaching the Tropic of Capricorn, latitude 23.5 degrees South. The sun has its most southerly rising and setting and peaks at 28 degrees. Oakland’s daylight is at a minimum for the year at 9 hours and 23 minutes. At the end of December, Oakland’s sunrise is 7:38 a.m. with sunset at 5:04 p.m.
The moon shifted from the morning to the evening side of the sun on November 29 (New Moon). On December 3, the crescent moon may be seen above the brilliant planet Venus in the 6 p.m. dusk, On the next evening, the moon appears below and to the right of the planet Mars at dusk (Dusk is the first hour after sunset while Dawn is the hour before sunrise.) On December 7, the evening moon appears half full. From December 5 through 9, the moon offers the most surface details through binoculars or a telescope. The moon is fullest on the evening of December 13, shining South of the horns of Taurus. As the moon was near its closest distance on the previous day, this full moon will also be brighter than the average full moon. This full moon in December is the Long Night Moon, the full moon closest to the start of winter (December 21). The moon in Oakland will rise at 5:06 p.m and not set until 7:49 a.m. the next morning. This full moon will be in view for 14 hours and 43 minutes. Full moons near the start of winter shine longest in the night sky, as they are nearly opposite the sun along the zodiac. On December 22, the moon appears near the bright planet Jupiter at dawn. On December 29, the moon swings from the morning to the evening side of the sun.
PLANETS: Brilliant Venus becomes visible within 20 minutes after sunset in the West, even before the sky is very dark. An hour after sunset, Mars can be seen as a ‘yellowish’ star above and to the left of Venus. Mars is about one hundredth as bright as Venus due to its greater distance from both the sun, Earth and its low surface reflectance. In the first dozen days of December, the innermost planet Mercury may be seen very low in the West within a half hour of sunset. In the eastern morning sky, the bright planet Jupiter may be seen in the southeastern dusk. On the last evening of 2016 (December 31), there will be a close line up of Mars and the distant planet Neptune. Neptune will be only a tenth of a degree from Mars, appearing above and to the right. Since Neptune will only be 1/630th as bright as Mars, you need to use binoculars mounted on a tripod or a telescope to glimpse the distant blue world.
2017 Night Sky Highlights: I have created a two page document that includes the dates of all the principal moon phases, the dates (either dusk or dawn) when moon and planets line up, the months when the 5 bright planets can be seen either at dusk or dawn and the times of sunrise and sunset for over 40 days in Oakland and 6 other area communities. You can get an electronic copy of 2017 Night Sky Highlights by emailing me a request at firstname.lastname@example.org.