Monday December 8th the inner most planet, Mercury, will be on the opposite side of the Sun from the Earth at what is called superior conjunction. That will happen at 10 UT (4 am CST). Coincidently at 21 UT (3 pm CST) Mercury reaches aphelion, its most distant point from the Sun for this orbit. It will be 0.4667 AU from the Sun and 1.451 AU from the Earth.
Mercury’s orbit takes it eastward so in a couple of weeks you can start watching for Mercury to reappear to the left or east of the Sun, setting after the Sun sets.
Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.