As 2018 winds down, the astronomical calendar continues its healthy pace. This month, we have a variety of interesting viewing opportunities – from close encounters to meteor showers, including planets, moons, two comets, and even some star clusters!
If you need a telescope to help enjoy this month’s night sky events, we have a guide to the best stargazing telescopes. From the Meade Polaris 130 (under $200) to the Orion Atlas 8 EQ-G GoTo ($2000), you can find one for your astronomy interest and budget.
Read on to learn about 10 amazing astronomic events in December, plus how and where you can see each one.
December 3 – Close Approach of the Moon & Venus
December starts off with a close approach, the first one between Venus and the moon since July. The best part about this close encounter – when the moon and Venus will pass within 3.5° of one another – is that the moon will be a small, waning crescent, just 12% illuminated.
This makes it a great opportunity to see Venus, as the moon won’t obscure your view with its light. Venus and the moon won’t both be visible through a single telescope lens, but you can easily view both with your eyes or a pair of binoculars. Look for Venus and the Moon to meet in the southwestern sky at sunset.
December 3 – C/2018 V1 Machholz-Fujikawa-Iwamoto at Brightest
While you’re out admiring Venus and the moon, there’s a second “last-minute” night sky event that’s rare enough to make it worth the effort to see.
Discovered on November 7th, Comet C/2018 V1 Machholz-Fujikawa-Iwamoto is a mouthful to say, but its name honors the three astronomers who identified it. On December 3rd, it will reach perihelion, at its closest point to the sun of 36 million miles. The comet will be viewable in the western sky (you’ll need binoculars for sure).
December 7 – Close Approach of Mars & Neptune
A few days after this close encounter, there’s another equally interesting one to look for. On December 7th, Neptune will make a close approach with Mars, that iconic orange dot in the sky. In fact, Neptune will pass so close to Mars (0°02′, to be exact), you’ll have a unique opportunity to see them both within the field of a single telescope.
This is the only night sky event this month you’ll need a telescope for, as Neptune is not visible to the naked eye. However, if seeing Neptune is on your list, this is a great opportunity. (It’s also a Friday night, so many public observatories may hold open viewing nights where you can go use a powerful telescope to really enjoy the view!)
December 8 – Close Approach of the Moon & Saturn
December is a busy month, as on December 8th there’s another close approach to look for. Saturn and the moon will pass within about 1° of one another in the southern sky at sunset. The moon will be only one day old at about 3% of full brightness, making this an excellent opportunity to see Saturn.
Saturn is also at an excellent tilt position, meaning that with a good pair of binoculars (or a telescope if you have access to one), you should be able to see Saturn’s rings quite clearly.
December 13/14 – Geminids Meteor Shower
Late on the night of December 13th (or early on the 14th), depending on where you live, the Geminids meteor shower will peak, reaching it’s expected maximum rate of 100 meteors per hour. While the Geminids meteor shower has been ongoing since about December 7th (and will continue through the 16th), the 14th is expected to be the best night for activity.
The Geminids are often considered the best meteor shower of the year after the Perseids – and they only lose the top spot because it’s colder in December than in August when the Perseids occur. Just be sure to bundle up to stay warm, and you’ll be in for a great show!
December 14 – Close Approach of the Moon & Mars
December 14th is a particularly exciting day, as there are two night sky events set to occur on a single night!
After the Geminids peak earlier on the day (the very early morning), the moon and Mars will have their own close encounter. Shortly after sundown, the moon will pass within 3.5° of Mars. As the moon will be at its first quarter, it should be easy to spot.
Look for these two celestial bodies in the southern sky after sunset.
December 15 – NGC 1981 is in Orion
This month, we’re highlighting a new type of night sky event, but you’ll definitely need binoculars (or a telescope) for this one. On the night of December 15th, the open star cluster NGC 1981 will be easy to spot. Look for NGC 1981 in Orion’s ‘sword’ hanging from his belt as he sits high in the southern sky. NGC 1981 is a cloudy-looking cluster of stars a close 1,304 light years from earth, making it one of the more distant objects in the constellation Orion.
While NGC 1981 is always located in Orion, Orion’s high position in the sky will make it easier to see the constellation and cluster. Look for these two at their best position around midnight local time.
December 16 – Comet 46P/Wirtanen at its Brightest
Don’t put your telescopes away yet! On December 16th, the Comet 46P/Wirtanen will appear at its maximum brightness, at a close distance of 0.07 AU (astronomical units, a measure of distance where 1 equals from the earth to the sun).
Comet 46P/Wirtanen will appear high in the southern sky late on the 16th (or early on the 17th depending on your location). Look for the comet with its cloudy tail of dust and ice near the Pleiades star cluster; you’ll need binoculars to get a good view, as it will be hard to see with the naked eye.
December 21 – December Solstice
The ‘night sky’ event of December 21st is actually not a single event; the whole day marks the December Solstice for planet earth. For those in the Northern Hemisphere, this is the shortest day of the year and begins the winter season; the southern hemisphere will experience the longest day of the year and start the summer season.
Depending on your location, this may not seem like a big deal, but for those above the Arctic circle or below the Antarctic circle, this marks the halfway point of the darkest or brightest part of the year. If you’re curious, there are some fascinating celebrations of the winter solstice you can enjoy too!
December 22 – Ursids Meteor Shower
While the Geminids are the star of December’s meteoric events, don’t forget that the Ursids occur too, peaking on the 22nd. The Ursids occur from December 17th to 25th, and their night of peak activity will see a maximum of about 10 meteors per hour. This may seem low after the Geminids, but the Ursids are still a respectable and consistent meteor shower late each year.
The Ursids radiate from the constellation Ursa Minor. Look for the North Star to find Ursa Minor, and then scan the whole northern sky to try and spot these meteors as they occur.
December 24 – Close Approach of the Moon & M44
For the final night sky event in December, the moon has one last close encounter. This time, it’s with M44, known as the Beehive Cluster. The moon will pass M44 within 0°17′; as the moon will be at almost full brightness (91%), its light will likely obscure M44 around the time. Instead, look for M44 near the moon in the hours before or after the close encounter (at sunset or the early hours of December 25th).
As pictured above, you can see that M44 is visible to the naked eye. Binoculars will help make the cluster and its component stars even clearer. Even without them, you can admire this open star cluster the same way that famous astronomers like Ptolemy and Galileo did.
Do you have questions about night sky events in December? Email/contact us!
Featured photo credit: Kaustav Ghose via Flickr