The skies may finally clear up for a bit leading into the weekend, giving us a chance to point a pair of binoculars at the half-lit Moon on the 19th. On that date, the small blue dot that’s Uranus can be seen a few Moon-diameters above it, a great opportunity to spot the outer planet using the Moon as a pointer.
Two days later, Winter Solstice officially occurs late Monday the 21st at 10:49pm CST, marking the shortest day and longest night of the year. On the Solstice, the Sun is in the sky for 7 hours 53 minutes, 8 hours and 42 minutes less than the length of a day around June 21st. This is why, these days, it seems that you’re spending most of your time in the dark.
Of course, December 21st has neither the latest sunrise nor earliest sunset: the earliest sunset already happened on the 12th, but earlier sunrises won’t occur until the first thing in January. The reason it doesn’t just do everything on the same day and get it over with is because of something called ‘The Equation of Time’, essentially an explanation of the conflict between Earthlings’ insistence in measuring time in days and years, and the fact that the universe has no need for such simplistic concepts as clocks and calendars.
Incidentally, ‘solstice’ comes from the Latin ‘solstitium’, meaning ‘the Sun stands still’. On this day, the Sun reaches its southern-most position as seen from the Earth, pauses above the Tropic of Capricorn and then begins moving northward again. In another of those ‘Equation of Time’ oddities, the day winter starts is the same day the Sun takes its first step toward summer. Can’t be too soon, in my opinion.
Oh, and if you happen to find yourself out at night trying to remember what I said about that Solstice stuff, see if you can pick out Polaris, the North Star. It’s the brightest thing straight north and little more half way up the sky. The Little Dipper hangs from Polaris by its handle, and below that, nearer the horizon, is the familiar Big Dipper.
The reason I bring it up it that just below Polaris is where the shooting stars of the Ursid Meteor Shower will appear to come from all this week. At an average rate of 10 per hour, the Ursids are not something people typically stand around waiting for in winter, but the occasional bursts of 100 meteors per hour have occurred, so if you’re out anyway, might as well glance up once in a while.
Planets, Meteors, Latin words and equations, all available from your own back yard.
