You better watch out, you better not cry, because Santa Claus is coming to town, and if it’s clear enough he may very well see you when you’re sleeping and when you’re awake, especially if you’re outside the night of Christmas Eve.

That’s because Santa will be able to use the full moon as a big spotlight. For the first time since Jimmy Carter was president in 1977, we have a full moon on Christmas Day.

Full moons at Christmas don’t happen all that often because of the 19 year cycle of the 29.5 day month of lunar phases combined with leap years.

But it’s happening this year, doing its usual job of whitewashing the night sky, especially if the lunar light is bouncing back into the sky off a fresh white cover of snow.

All but the brighter stars and constellations get washed out with the sky lit up like a bright Christmas tree. Full moons are especially rough on stargazing this time of year because they trace a very high arc across the sky through the course of the night. In fact, they take about the same high arc across the sky as the sun on the first day of summer.

If you’ve been good this year, you may get a new telescope under the Christmas tree, but unless you want to get really frustrated I’d wait until New Year’s to give it “first light” from the stars. The moon rises much later at night and the early evening skies are a lot darker.

Even though the sun has a much lower profile this time of year, it’s about to make its big annual move on Monday at 10:48 p.m. That’s the moment of the winter solstice, the first day of winter and also the moment we start gaining daylight once again.

This time of year you’ve no doubt noticed that the sun takes a very low arc across the southern sky, rising in the southeast and setting in the southwest, and spending less than nine hours above the horizon. Monday is the day the sun reaches its lowest point in the southern sky. We’re not being delivered nearly the amount of solar power as we get in the summer.

From now through late June the sun’s arc across the heavens will get higher and we’ll eventually get warmer. However, the coldest weather of the winter is yet to come. That’s because of the north polar regions where there’s been little or no sun since autumn began in September.

For some time now super cold air has had a chance to build up. Because of the Earth’s rotation and general wind circulation patterns, the polar cold has to go somewhere. Naturally some of it will spill our way in intervals well into the spring. I call it the polar hangover effect.

The sun’s daily path in the sky is a reflection of the Earth’s daily and annual motions. Since you were a little kid you’ve known that Earth’s rotation causes the sun to rise in the east and set in the west. The Earth’s orbit around the sun also affects how we see our home star in the sky, mainly because of the fact that the Earth’s axis is tilted to its orbit around the sun by a 23.5 degree angle.

On Monday, on the day of the winter solstice, the northern hemisphere of the Earth where we live is tilted at the maximum angle away from the sun’s most direct rays.

The noontime sun is shining directly over the latitude line called the Tropic of Capricorn, which lies 23.5 degrees in latitude south of the equator. In our Butler skies much farther to the north, the noontime angle of the sun will be as low as it can be at about 25 degrees above the southern horizon.

Six months later, around June 21, after we travel half our orbit around the sun, we’ll have our summer solstice. On that date the northern hemisphere will be basking in the sun’s most direct rays. That will be reflected in our sky as the sun takes a long, high arc from the northeast to the northwest horizon.

On the day of the summer solstice the noontime sun reaches its maximum height, around 71 degrees above the southern horizon.

Ancient and not so ancient cultures were keenly aware of the sun’s annual cycle in the sky and many of them worshipped the sun. In fact, there was a lot of sun worshipping going on in northern Europe. I’ve seen much evidence of this in my travels.

Ancient observatories and “temples” like Stonehenge in southern Great Britain and Newgrange in Ireland are examples of this. It’s no accident that the early Catholic Church established Dec. 25 as Christmas Day, the day that Christ was born. No one really knows the exact date of Christ’s birth, but one of the reasons the church chose Dec. 25 was to battle against the great pagan celebrations that occurred around the time of the winter solstice, when the sun was “reborn” and started its upward climb into the sky.

I wish you and yours a blessed holiday season, hoping that Santa and his reindeer don’t get too moonstruck this year!

Mike Lynch is an amateur astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis/St. Paul and is author of the book, “Stars, a Month by Month Tour of the Constellations” published by Adventure Publications and available at bookstores and at www.adventurepublications.net.