Jeffers Foundation

PHENOLOGY & ASTRONOMY

Data from Freshwater Society Minnesota Weatherguide Environment Calendar and Almanac (Jim Gilbert for Phenology and Rod Nerdahl for Astronomy)

Phenology

Phenology: Third Week of December

On cold days beautiful intricate frost patterns appear on windows, in swirls and feathers, fronds and trees, and sometimes a mini-scene of a forest after a snowfall. Because the sun is low in the sky, the sunlight casts the longest shadows of the year. Mosses in forests become lush green on days when the temperature rises above freezing.

December 17, 2016 - The 117th annual Audubon Christmas Bird Counts began and continued into the first week of January. These single-day counts are made in thousands of areas across the U.S. and beyond with about 75 in Minnesota. In the aribault/Northfield area, observers saw 50 species and over 7,000 individual birds, including 689 mallard ducks, 673 dark-eyed juncos, 338 black-capped chickadees, 224 northern cardinals, 186 wild turkeys, 61 ring-necked pheasants, 28 bald eagles, and one great blue heron.

December 18, 2016 - Freeze-up date for Grindstone Lake in Pine County, one of the last lakes to freeze over each year.

View the December Phenology Information from the Freshwater Society Minnesota Weatherguide Environment Calendar and Almanac >>

Species of the Month

White-tailed deer (Odocoileus virginianus)

White-tailed deer (<em>Odocoileus virginianus</em>)
Justin Pruden

Deer have keen senses, including excellent eyesight and hearing, but like many mammals they rely heavily on the sense of smell to understand their world. They are constantly sniffing the air. Having strict territories, most white-tails live within an area of 50 to 300 acres, depending on food supply and cover. Deer survive because they know their territories well. If one is chased by a predator it stays within its territory, bounding on trails through familiar tree stands and brush. A deer can sprint close to 40 miles per hour. Deer are browsers, eating thin twigs of northern white cedar, sugar maple, basswood, and more for buds and new bark. Each winter day they eat five pounds of browse for every 100 pounds of weight.

Astronomy: December

Highlights
Highlights
The stars of the Winter Circle are in the east at sunset, crossing the meridian at midnight. Not only does the clear, cold winter air make the stars appear brighter, they are brighter. Many of the brightest stars are found here, as they are our neighbors, huddled along with the Sun on the inside edge of the Orion Spur, of the Perseus Arm of our galaxy. An overhead view of our galaxy shows these stars are closest to our Sun, opposite from the center of our galaxy. While the summertime Milky Way is brighter, our winter neighbors are closer, though not as numerous.

Morning Stars

Mercury starts the month eight degrees above the horizon at sunrise and is joined by the moon on December 5. It climbs to Greatest Western Elongation on December 14 at 21.3 degrees from the Sun, which makes it the best time to view. Look for it eight degrees above the east-southeast horizon one hour before sunrise. Venus is also climbing to Greatest Western Elongation, but won't get there until next month. Regardless, it will be a great time of the year to see it. By mid-month, Venus is standing a full 30 degrees above the horizon at sunrise. The Moon will be nearby on December 3. By the end of the month, Jupiter is climbing higher in the morning sky, appearing 10 degrees above the horizon an hour before sunrise.

Evening Stars

Saturn finishes the year heading into the Sun. Catch it early in the month, when it will be 15 degrees above the southwest horizon at sunset, joined by the Moon on December 8. By year's end, Mars is the last planet standing in the evening sky. It starts in the southeast at sunset and sets in the west each night, just before midnight. The Moon will stop by on December 14.

Sun Declination

View the December Astronomy Information from the Freshwater Society Minnesota Weatherguide Environment Calendar and Almanac >>

LOOK FOR

Freeze-up for Lake Minnetonka:
2016 December 15
2015 December 31
2014 November 27
2013 November 29
2012 December 22

TEACHER PHENOLOGY PREVIEW

TEACHER ASTRONOMY PREVIEW

December ASTRONOMY PHENOMENA

7th, New Moon Little Spirit Moon (Ojibwe) - 1:20 am

7th, Mars 0.03 degrees south of Neptune - 8:56 am

8th, Moon near Saturn in southwest - After sunset

12th, Moon apogree (251,765 miles) - 6:25 am

14th, Geminids Meteor Shower peak - 12:20 am

15th, First Quarter Moon - 5:49 am

21st, Mercury 0.87 degrees north of Jupiter - 8:43 am

21st, December solstice; winter begins in N Hemisphere - 4:23 pm

22nd, Ursids Meteor Shower peak - 8:46 am

22nd, Full Moon - 11:49 am

24th, Moon perigee (224,353 miles) - 3:48 am

29th, Last Quarter Moon - 3:34 am

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