December is wonderful for DeSoto County star-gazers.
On Dec. 16, for instance, the comet 46P/Wirtanen will be closest to the earth, a mere 7.1 million miles and some change away. It will be low in the eastern horizon at dusk. Comet Wirtanen, a Jupiter family coment discovered in 1948 by astronomer Carl Wirtanen, is a short-period comet making its journey around the sun every 5.5 or so years. However, this will be the best apparition in many centuries, as it zooms in close to our home planet.
Short-period comets become famous as they grace our skies (every few years or so) and become well known. In doing this, however, they lose material in each orbit around the sun ... and like a moth around a flame, they slowly burn up. Comet Wirtanen is small, the nucleus being only about 7/10th of a mile in diameter. This is about 1/10th the size of Halley’s Comet and 1/13th the size of Comet Hale Bopp. Comet Wirtanen is going to be very near the earth by mid-month and is predicted to be within the realm of naked eye visibility. Not much of a tail is predicted with this comet, though.
The last couple of months have held some famous meteor showers, and December holds one of the most spectacular ones. Geminid meteors, for example, are unusual because they do not originate from a comet, but from an asteroid named 3200 Phaethon. The peak of the Geminid meteor shower is the night of Dec. 13 and into early Dec. 14, with as many as 120 meteors per hour reported in past years! Good news is that the moon will set early this night and be a waxing crescent with only a 32 percent illumination. So, moonlight will not pose a problem drowning out fainter meteors. You do not need any special equipment to view a meteor shower, in fact you are better off without it. Just remember to avoid city lights and bundle up as December nights even in Florida can be quite cool! A lawnchair is advised, as you would like to be as comfortable as possible to stay out all night. Snacks and cocoa are a good idea too.
Meteors can be seen in any part of the sky ... but all true Geminids will radiate from a point in the constellation Gemini (the twins); look to the stars Castor and Pollux for the radiant point that is near Castor.
Remember, unshielded floodlights are spoiling these views, so talk to your neighbors about properly screening outdoor lighting. Outdoor lighting, in fact, doesn’t necessarily add any additional security to your property and only serves to confuse nocturnal animals depending on the phases of the moon’s light and darkness for their natural cycles. If you truly love animals and nature, do not turn night into day. And preserve our beaches, rivers, jungle forests and night sky at all costs—consider your actions, as they can affect many things, some you don’t realize, in our fragile environment.
Former Arcadian Victor C. Rogus (F.R.A.S.) is a fellow of the Royal Astronomical Society, London, living in Sedona, Arizona