Wednesday, April 23, 2014
By Bernie Reim
December always marks the beginning of winter for us in the northern hemisphere. This year the winter solstice will happen at 12:11 p.m. on the 21st. That is the lowest point that the sun will reach for the year. The word solstice means “sun stands still,” which is what it will appear to do for a few days before it begins once again to rise higher in our sky as our days will get longer again. Track and mark the sun against a foreground of trees or a landmark to prove this for yourself.
SKY GUIDE: This chart represents the sky as it appears over Maine during December. The stars are shown as they appear at 9:30 p.m. early in December, at 8:30 p.m. at midmonth and at 7:30 p.m. at month’s end. Jupiter is shown in its midmonth position. To use the map, hold it vertically and turn it so that the direction you are facing is at the bottom.
Sky chart prepared by George Ayers
There will be many exciting highlights upcoming. The most exciting and unpredictable one will be Comet ISON after it swings around the sun in late November. If it survives its close encounter with the sun, it could get quite bright in our morning sky even if it breaks apart.
Comet ISON will be visible low in the east-southeastern sky half an hour before sunrise to the left of Saturn and Mercury. Watch as the comet then gets higher in the sky, but it will also start to fade as it gets farther away.
A slender waning crescent moon will appear directly between Saturn and Mercury half an hour before sunrise on the morning of Sunday, Dec. 1. The comet will be about 10 degrees to the left of this luminous trio.
The Geminid meteor shower will peak on Saturday morning the 14th. You could normally expect more than 60 meteors per hour from this predictable shower, but this year the moon will be just three days before full, washing out many meteors.
This is a more mysterious meteor shower than most because it is caused by an asteroid named 3200 Phaethon instead of a comet. This asteroid, just discovered in 1983, may be a dead comet nucleus, but it is still shedding material. These meteors will leave brighter streaks because the material is denser and will burn up in our upper atmosphere at about 80,000 mph, which is much slower than other showers like the Perseids, Orionids and Leonids.
So find a dark sky site with an open view and bundle up and enjoy one of nature’s great spectacles that will put you more in tune with Earth, our life-giving atmosphere and the sky.
Brilliant Venus will reach its maximum magnitude for the year in December. You can see it best about one hour after sunset low in the southwestern sky. Through a telescope you will see that it is slowly getting larger and thinner as it gets closer to Earth even as it gets less illuminated. Watch as a slender waxing crescent moon passes above it on the evening of the fifth.
Jupiter now rises shortly after sunset in the constellation of Gemini, which is part of the famous hexagon that becomes quite prominent in the eastern sky as winter approaches. The king of the planets will reach opposition early next year, when it will be at its best and brightest for the whole year. Watch the full moon pass near Jupiter on the evening of the 17th and 18th.
Mars is slowly starting to get brighter and closer again, now rising a little after midnight.
Mercury will be in our morning sky for the first half of December, and Saturn will be visible in the morning sky all month, rising around 5 a.m. Comet ISON, changing position a little each morning, will create an interesting celestial dance with these two planets.
(Continued on page 2)