The comet, coined the Christmas Comet, because of it’s timing, is the thing to track right now. This, the 46P/Wirtanen, will be the brightest comet this year. If you are into stargazing, get ready, as it will be its brightest on December 16, 2018 but should also be visible 14-18 December. You don’t need a strong telescope for this. Here are some leads on how to get a view of the comet, plus the Geminids, this month.
How to See the Christmas Comet
This Christmas Comet orbits around the Sun between the Earth and Jupiter.
You don’t necessarily need a telescope. Get out the binoculars! You’ll get the best chance of a view between December 14 and 18. (My article on choosing binoculars has some tips on how best to use binoculars for good views of night sky objects.)
Where to Look
Because where to look will vary with your location and time, it’s best to refer to a live sky chart, to help with ascertaining which part of the sky to look to view Comet 46P/Wirtanen.
With the SkyLive tool, all you need to do is select the closest main city to you, and then you can refine the site by modifying the coordinates.
For example, the default location is Greenwich, UK. Click the [change] link beside it and then select your nearest city/town. Alternatively, you can enter the exact latitude and longitude of your location. Then hit ‘submit’
You’ll be given multiple information sources, including the rise and set azimuths and the transit max altitude with times.
You’ll find a simulator of the orbit and a table of the ephemerides (coordinates of a celestial body) of 46P/Wirtanen for the past and next 7 days, plus more.
What Else to See At Christmas
The Geminids meteor shower will also be visible. This is the dust and debris from an asteroid called 3200 Phaethon. See if you can get a glimpse of this between 13-16 December.
In the northern hemisphere, you could see up to 120 meteors/hr if you can get yourself to a dark location, around the time after the first quarter moon sets around midnight your local time.
In the southern hemisphere? You should still see plenty of medium-speed meteors. Look for the constellation Gemini. It rises above the horizon after midnight local time.
You can see a video of what else is up in the sky in December 2018 at JPL NASA.
Usually 46P/Wirtanen is too far away for us to see. It orbits the Sun approximately every 5.4 years. This December it will be close enough to see from Earth at about 7.2 million miles (30x the distance to the Moon) away from us and with a magnitude of between 3 and 7.5. The naked-eye magnitude falls within this. However, more experienced observers are saying around magnitude 5, which is near the extent for naked-eye viewing. Hence, using a set of binoculars or a standard DSLR camera may guarantee a better view.
This should be a fun activity to include your kids with their telescopes.