Comet 46P/Wirtanen is fast approaching its closest encounter with Earth on Dec. 16th. Despite this close approach, it is barely visible to the naked eye which is in part due to its tiny icy nucleus that is only about 1km. Compare that to some great comets of recent memory like Halley (~15km) and Hale-Bopp (~30km) and you can understand why. Currently, 46P/Wirtanen is only glowing bright enough to be barely visible to the naked eye and doesn’t have that long, blue, icy tail that we often imagine when we think of comets. However, a pair of binoculars, a backyard telescope or a digital camera will certainly make your viewing a lot easier.
Fortunately, if attempting to view a comet is something on your bucket list, you’re in luck this weekend as it looks as though Saturday night and Sunday night both appear to be clear or clearing. Saturday may have some lingering clouds from the system that has brought us rain and fog the past couple of days but those will certainly be out of the way by Sunday night. Additionally, you might even luck out and catch the some meteors since the tail end of the Geminid Meteor Shower is still going on! Viewing instructions are the same as they are for the meteor shower. Try and get away from city lights the best you can, give yourself 20-30 minutes for your eyes to adjust and use the image below to guide your eyes to the nearest constellation (Pleiades) to find the comet.
Since many of us may not be able to pick it out without a camera, telescope or binoculars, I wanted to take a look back at some past comets to see if there was any hope for a more substantial comet coming in the future. I think most of our followers can probably remember the 1996-1997 passage of Hale-Bopp which was visible in the sky for a staggering 18 months. I remember seeing that comet as a kid completely mesmerized. Who would have thought 20+ years later I’d be writing about one? Go back 10 years prior and some people may remember Halley’s comet in 1986 or one decade further in 1976 to Comet West, perhaps. In recent years, although not for the northern hemisphere, two major comets were seen – Comet McNaught (2007) and Comet Lovejoy (2011). From what I have been able to gather from my trusted websites online, it seems as though about every 5-10 years or so we can expect to see a comet. The more impressive ‘Great’ comets average return periods of 20-30 years. So, while we don’t have a more impressive comet in the immediate offing, we probably aren’t too many years away from another truly special comet.