December has finally arrived, which means 2022 is coming to an end. Before we dive in, we want to wish everyone a happy holiday season and hope you finish the year on a positive note!
(Looking for last month's astronomy events? View November 2022)
If you're interested in exploring the night sky of December 2022, this article is for you. From two spectacular meteor showers to a Mars opposition, this month is full of things to see for the curious astronomer.
9 astronomical events in December 2022:
- Full Moon - 12/7 @ 11:09pm EST
- Mars at Opposition - 12/8 @ 12:41am EST
- Geminids Meteor Shower Peak - 12/13 to 12/14
- 3rd Quarter Moon - 12/16 @ 3:57am EST
- Winter Solstice - 12/21 @ 4:49pm EST
- Mercury at Greatest Eastern Elongation - 12/21 @ 5:05 to 5:18pm EST
- Ursids Meteor Shower Peak - 12/21 to 12/22
- Super New Moon - 12/23 @ 5:18am EST
- 1st Quarter Moon - 12/29 @ 8:21pm EST
Keep reading if you would like to explore each of these upcoming events in a bit more detail.
Astronomy events to mark on your calendar this month:
12/7 - Full Moon | Cold Moon
The final Full Moon of 2022 occurs on Wednesday, December 7th at 11:09pm EST. Not only is it the last for the year, but it's also the last for the Autumn season (in the Northern Hemisphere).
During the Full Moon phase of the lunar cycle, it transitions from a waxing gibbous moon to a waning gibbous moon.
As the fully illuminated Moon appears to be positioned opposite to the Sun in ecliptic longitude, from our perspective on Earth, it will be seen rising around sunset and setting around sunrise. To be precise, the Moon will rise above the horizon at 4:04pm EST and set below the horizon on December 8th at 7:04am EST.
December's Full Moon is commonly know as the Cold Moon.
Additionally, due to this Full Moon's proximity to the Winter Solstice (the longest night of the year) this event is also referred to as the Long Nights Moon.
A few minutes after the Full Moon, it passes Mars along the ecliptic at 11:18pm EST. This event is called a lunar occultation, and simply refers to occasions in which the Moon appears to pass in front of a planet.
12/8 - Mars at Opposition
On December 8th at 12:41am EST, just a few hours after the Full Cold Moon, the planet Mars will be at opposition. This event occurs about every two years.
For those who are unfamiliar, opposition occurs when a planet is positioned 180 degrees away from the Sun. This means, from our perspective on Earth, Mars will appear in the complete opposite end of the sky away from the Sun's position.
Another way to picture this is to imagine the Sun, Earth and Mars all in a straight line, with Earth placed in the middle.
Mars will rise above the eastern horizon as the Sun is setting and will descend below the western horizon as the Sun rises the following day.
At opposition, Mars will appear largest and at its maximum brightness for 2022 at magnitude -1.9. However, since the bright Full Moon also occurs on this day with an approximate magnitude -12.74, it may be a bit difficult to observe the more dimly lit Mars with the naked eye.
Therefore, this is a great opportunity to take out a pair of binoculars or a quality telescope to get a clearer view of our celestial neighbor. Make sure to look towards the Taurus constellation where Mars is currently situated near Aldebaran (the brightest star in Taurus).
If you miss this, you'll have to wait until January 2025 for the next Mars opposition.
12/13 to 12/14 - Geminids Meteor Shower Peak
Over 100 meteors are recorded in this composite image taken during the peak of the Geminids meteor shower in 2014. Credit: NASA
In 2022, the Geminids meteor shower is active from November 19 until December 24th. The peak, however, occurs from December 13th into the morning of December 14th. During this time you may be able to see up to 150 meteors per hour, according to the American Meteor Society. This figure is commonly referred to as the ZHR or Zenithal Hourly Rate.
Although most meteor showers are associated with a comet, the Geminids are not. This meteor shower originates from 3200 Phaethon, an asteroid that was discovered October 11, 1983 by NASA's Infrared Astronomical Satellite.
The location in the sky from which the Geminids appear to emanate (the radiant point) is the Gemini constellation. However, this is not where you should direct your gaze. In fact, the closer a meteor is to its radiant point, the more difficult it is to spot due to its shorter trail.
For best meteor shower viewing, you should be in a dark location with limited light pollution. Then, simply gaze up at the sky to observe as wide an area as you can. The broader the area of sky you can take in, the higher the likelihood of witnessing a meteor zoom by.
12/16 - 3rd Quarter Moon
The Moon begins to wane after its peak during the Full Moon. Its approximately 29 day cycle goes from full illumination during Full Moon to complete darkness during New Moon.
On December 16th, the Moon will reach the 3rd quarter phase of its lunar cycle. This part of its apparent journey will be reached at 3:57am EST when it will be seen rising above the eastern horizon around midnight and will be half-illuminated on its western side.
12/21 - Winter Solstice
The Winter Solstice marks the beginning of Winter in the Northern Hemisphere. In 2022, this moment falls on December 21st at 4:49pm EST. In terms of hours of sunlight this date provides only 8 hours and 59 minutes of the Sun's rays and, therefore, becomes the shortest day of the year.
From our perspective on Earth, the Sun will appear at its lowest point in the sky above the horizon (opposed to it appearing at the highest point during the Summer Solstice on June 21st).
During the Winter Solstice, the North Pole is tilted at its furthest point away from the Sun.
This is also the longest night of the year and it provides the broadest window of time for dark night celestial viewing. Not that we recommend you gaze at the stars for 15 hours, but you could (give or take a few hours for twilight).
12/21 - Mercury at Greatest Eastern Elongation
Mercury, the closest planet to the Sun, will reach its greatest eastern elongation on December 21st between 5:05 to 5:18pm EST. During this period, Mercury will extend 20 degrees and 5 minutes away from the Sun.
Why does greatest elongation matter? Since Mercury is positioned so closely to the Sun, the planet can often be difficult to view as the Sun's light rays can outshine it.
However, the further away Mercury is from the Sun, the better it can be observed. Hence, the significance of its greatest elongation date.
When Mercury is at its greatest eastern elongation it will appear most visible after sunset. At this time, Mercury will be shining at magnitude -0.6 in a waxing gibbous phase (yes, similar to the Moon, Mercury also has phases).
12/21 to 12/22 - Ursids Meteor Shower Peak
Between the 13th and the 24th of December, the Ursids meteor shower will be active in the sky. This is the last meteor shower of 2022. According to the American Meteor Society, the Ursids peak at 10 meteors per hour on the night of the 21st through 22nd.
The Ursids meteor shower derived its name from the constellation Ursa Minor, due to the fact that the meteors appear to emanate from that area. The origination area of a meteor shower is known as the radiant point.
As mentioned earlier, the radiant point is not where you should fix your gaze during a meteor shower observation. Instead, try to observe as wide an area of sky as you can. The broader your view, the better the chance of spotting a meteor pass by.
Additional viewing tips:
- Position yourself in a dark location away from bright city lights
- Bring along a comfortable lawn chair on which you can comfortably recline
- Allow about 30 minutes for your eyes to adjust to the darkness
- Dress appropriately for the cold winter temperatures
The comet associated with the Ursids meteor shower is 8P/Tuttle. It has a 13.6 year orbit and was discovered in 1858 by Horace Parnell Tuttle.
12/23 - Super New Moon
The New Moon on December 23rd is a Super New Moon. Why Super? Well, because the event takes place close to its perigee (closest point to the Earth).
5:18am EST is the moment the Moon begins its new lunar cycle. This New Moon phase occurs when the Sun and the Moon appear to be positioned at the same ecliptic longitude.
During this time the Moon will appear mostly invisible to the naked eye. These darker-than-usual nights provide great opportunities for stargazers to explore the skies. Particularly to observe celestial objects that are harder to find under more illuminated conditions.
12/29 - 1st Quarter Moon
The final highlighted event this month occurs on December 29th at 8:21pm EST. At this time the Moon will reach its first quarter phase of the lunar cycle.
The Moon will be positioned 90 degrees from the Sun and shine half-illuminated on its eastern side. On this day, it rises above the horizon around mid-day and sets around midnight.
Now that you're aware of the fascinating astronomical events in the sky this month, be sure to take the time to view them.
Many of the events mentioned above can be observed without any special optical equipment. However, to get the most out of your stargazing experience we recommend a quality pair of binoculars or a good telescope which can significantly enhance your celestial observations.
If you're in the market for purchasing or upgrading your astronomy gear, AstroTelescopium has a curated selection of products from industry-leading brands that can assist your exploration of the night sky.