Campfire at night in winter

Eyes on the skies — December

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, 2021:

The sun

Many people believe that on the Winter Solstice, usually around December 21, we experience the earliest sunset and latest sunrise.

However, while the Winter Solstice marks the Sun’s lowest point in the sky at solar noon and the day with the least amount of light, the earliest sunset always occurs earlier in the month, and the latest sunrise usually occurs in early January.

This year, for a viewer at 45 degrees north, the earliest sunset occurs around December 10. That means, as of December 11, our sunsets occur later each day until they peak in June.

The sun completes its apparent southerly drop on the Winter Solstice on December 21 at 10:57 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.

snowy sunset through trees

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

The moon has long captivated observers of all ages.

December’s lunar phases are as follows:

  • New moon on December 4
  • Waxing crescent on December 8
  • First quarter moon on December 11
  • Waxing gibbous on December 15
  • Full moon on December 19
  • Waning gibbous on December 23
  • Last quarter moon on December 27
  • Waning crescent on December 29

lunar phases

The brightest planets

Have you noticed a really, really bright light in the southwest shortly after sunset? If you have, you are not alone in wondering about this amazingly bright object that isn’t an airplane but seems to slowly set with the stars.

You have spotted the planet Venus which, on December 7, is at its brightest for the next few months. Venus is so bright that, in a clear blue sky free of pollution, you can see it during the daytime without telescope or binoculars.

Unlike the outer planets Jupiter and Saturn that appear to be visible in the sky for many months, Venus (and the other inner planet Mercury) appear in the west (at sunset) or in the east (at sunrise) for only a few weeks to a few months.

On the night of December 10, Venus joins Jupiter, Saturn, and the Moon in making a lovely sunset display as shown below.

Planets in the night sky
The locations of Venus, Saturn, Jupiter and the Moon from the southwest to south around 6:00 p.m. on December 10th. Image: SkySafari 6 Pro

Meteor showers

December has two meteor showers to note: the Geminids and the Ursids.

meteor shower

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.

This year, unfortunately, the Geminid meteor shower occurs near full moon, from which the light will block out the viewing of all but the very brightest Geminid meteors.

The Ursid meteor shower peaks on the night of December 21, but 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.

Map of the constellations

Learn about Eridanus, Lepus and Monoceros here.

This completes our review of the December skies…

Come back next month to learn about the calendar.