Welcome to the Ontario Parks “Eyes on the Skies” series. This will cover a wide range of astronomy topics with a focus on what can be seen from the pristine skies found in our provincial parks.
December brings some of the darkest skies of the year.
Take advantage of this great opportunity to go out into our parks. Breathe in the peace and solitude of December days and the bounty of the starlit skies.
Here are our astronomical highlights for December, 2020:
The sun completes its apparent southerly drop on the winter solstice on December 21 at 5:02 am.
In ancient times, people from many civilizations north of the equator were joyed with the cessation of the sun’s apparent southerly movement and celebrated the beginning of its northerly rise.
See our post from March to learn more about the solstices and equinoxes.
Sunrise and sunset times:
|December 1||December 15||December 31|
|Sunrise||7:47 am||8:12 am||8:08 am|
|Midday||12:15 pm||12:21 pm||12:29 pm|
|Sunset||4:42 pm||4:41 pm||4:50 pm|
The moon has long captivated observers of all ages.
December’s lunar phases are as follows:
- Waning Gibbous on December 4
- Last quarter on December 8
- Waning crescent on December 11
- New moon on December 14
- Waxing crescent on December 18
- First quarter on December 21
- Waxing gibbous on December 26
- Full moon on December 30
Did you know many First Nations teachings, including those of the Anishinaabe and the Haudenosaunee people, use the back of a turtle’s shell as a lunar calendar?
Learn more here.
The planets — Mars, Jupiter, and Saturn
Mars continues to be a bright ruby-like star in the evening sky and is well placed high in the sky after sunset.
After almost nine months of Saturn- and Jupiter-watching, these two planets are finally closing their evening gala (they’ll return in a few months to early-morning viewers at sunrise).
However, like many performers, they will leave us with a special encore event — a Great Conjunction.
A conjunction occurs when any two objects line up with each other as viewed from Earth. These objects can be planets, and our moon in combination with each other or with other interesting objects such as stars, nebulae, etc.
Conjunctions occur because Earth, moon, and other planets are in motion, which changes their relative angular distance to other objects in the sky.
See how Jupiter and Saturn are nicely lined up as viewed from Earth?
All three planets are orbiting the sun in a counterclockwise direction as viewed from this vantage point.
Planets that are closer to the sun orbit faster. As a result, Jupiter is passing Saturn, and Earth is passing both of them even faster. This motion is what is leading to the December 21 “Great Conjunction.”
On the evening of December 21, the two planets will appear to be almost one object. They will be about 0.1 degrees apart, which is about the limit of resolution of the human eye for many people and about 1/6 of the diameter of the moon.
In even a small telescope, viewers will have a great view of the planets and their numerous moons.
Note: you will need a very good view of the southwestern horizon. Any large trees, hills, etc. in that direction will surely block your view.
December has two meteor showers to note: the Geminids and the Ursids.
The Geminid meteor shower, peaking on the night of December 13 into the morning of December 14, is one of the best annual meteor showers to see.
In any given year and under a moonless night, the Geminid meteor shower usually outperforms the much more famous Perseid shower in August. However, due to the cold temperatures and often cloudy skies of December, it is far less known.
However, this year, we are lucky in having a new moon phase near its peak and with its high number of possible meteors (150 per hour at best), this year could be quite a show!
The Ursid meteor shower peaks on the night of December 21, so if you are out watching the Great Conjunction, why not look up and see if you can see any meteors! Keep in mind that this is a fairly weak meteor shower, producing no more than 10 meteors per hour at best.
Featured constellations: Eridanus, Lepus and Monoceros
As we round out the year of constellations, we will focus on some of the fainter ones seen at this time of the year.
Learn about Eridanus, Lepus and Monoceros here.
This completes our review of the December skies…
Come back next month to learn about the calendar.