The month of December sees the winter solstice, the shortest day of the year. One could argue that for this reason, December is one of the best months in the year for stargazing. Although it gets very cold at night, so wrapping up warm is essential. This year the winter solstice occurs on the 21st December with only 7 hours 29 mins of daylight.
The Geminids meteor shower peaks this month. It is usually a good shower but the Moon will make it hard to see them this year unless you stay up very late. There are two special events this month. On 5th December the Moon passes in front of the planet Uranus in an event know as an occultation. On the 8th another occultation takes place, this time of Mars. Both events will be best seen in a telescope although the Occultation of Mars will probably be possible to see with the naked eye.
Sun and Moon
|Date||Sunrise (Irish Time)||Sunset (Irish Time)|
Mercury is poorly position for the first part of the month. It improved as the month goes on and should be visible after the sun sets at the end of the month. Look for it low in the southwest and make sure the Sun has set before looking. On Christmas day, Mercury, Venus and Moon will be all low in the southwest
Venus is visible in the evening sky and improves as the month goes on. It’s visible low in the south west.
Mars is at opposition this month on 8th December and will be prominent throughout the night. It will be visible in the south above Orion. On Thursday 8th of December the Moon will occult Mars in the early hours of the morning. This is best seen with binoculars or a telescope but will be also visible to the naked eye. Mars will disappear behind the Moon around 4.55 (Irish time) and reappear 1 hour later at 5.55. The time will vary slightly depending on your location so it’s worth watching a few minutes early.
Jupiter remains in the sky in December. It will still be bright and unmissable early in the evening in the south. On the evening of 29th December, the moon will be close to Jupiter.
Saturn is visible in the west just after sunset. On the evening of December 26th the crescent moon is close by Saturn.
Stars and Constellations
The above sky chart, from heavens-above.com is for 23:00 on 15/12/2022. You can click on the chart to open a new tab and bring you to Heavens Above. On this website you can generate a custom chart for the time and date you wish. The summer constellations are gone and the winter constellations are rising earlier each night.
To the northwest are Cepheus (the house), Cassiopeia (the queen), Andromeda and Pegasus (the flying horse). Andromeda is the location of the Andromeda galaxy which is the furthest object that can be seen with the naked eye. Although, you will need very dark skies to see it. Andromeda and the Milky Way galaxy are headed for a collision and will collide in an estimated 4.5 billion years.
In the south at this time of year, is the constellation of Pisces (the fish) and Aquarius (the water bearer). Mars is also in this area of the sky. Over in the east we have the winter constellations rising. You will see Taurus (the bull) which has a distinctive “V” shape and beside it the Pleiades or M45. Also visible will be Orion (the hunter). Most people are somewhat familiar with this constellation and will be able to pick out Orion’s belt. You may also be able to pick out the Orion nebula just below the Orion’s belt. This is a star forming region 1,344 lightyears away. Finally, low on the eastern horizon is Sirius in the constellation of Cannis Major (the dog). This is actually the brightest star in the sky, although we never see it at its best as it doesn’t rise very high from Ireland.
The Geminid Meteor Shower
The Geminid Meteor Shower peak happens in mid December each year. It is one of the best showers of the year but occurs in the winter when it can get very cold. This year the peak is expected to happen on the 14th December. This year the Moon will be very bright which means it will wash out all but the brightest meteors. The Geminids are known to produce quite a few bright meteors so it is still well worth watching. The best time to watch is the nights of 13/14th and 14/15th December. If you want to get the best conditions possible, try setting your alarm for around 3am on the 14th as the Moon will have set.
To watch the Geminids, make yourself comfortable. A sun lounger or hammock is ideal. Also make sure you are warm, a sleeping bag can be very useful for this, as are hot drinks such as tea or hot chocolate! At this time of year you will need extra thermal layers, hats, gloves and scarves to make the experience enjoyable. You can look in any direction as the meteors will appear all of the sky.