A new, cold, dry air mass brought us crystal clear skies last night. And that allowed what heat we managed to build up Friday to radiate out into space. The result? A brilliant full moon and the coldest temperatures for Baltimore since March 8, when the overnight low reached 14 degrees.

It was 22 degrees this morning out at BWI. That wasn't a record. The low mark for Baltimore on a Nov. 24 is 17 degrees, reached most recently on this date in 1989. The thermometer out here on the WeatherDeck in Cockeysville reached 20 degrees at 7 a.m., just before sunrise.

Here are some other 7 a.m. readings from across the region:

Reagan National:  31 degrees

Dulles International:  23 degrees

College Park:  25 degrees

Annapolis:  33 degrees

Philadelphia:  28 degrees

Ocean City:  28 degrees

Unfortunately, clouds will be increasing today and tonight, with rain in prospect for Monday. But if you happen to be outdoors tonight - or anytime for the next few weeks - and skies are clear, turn toward the northeast and look for a bright, reddish "star" rising over the horizon. By 9 or 10 p.m. it should be well above the trees. It's Mars, about 60 million miles away and closing rapidly toward its opposition - and closest approach - at Christmastime.

It may look remote and alien, but it is fast becoming one of the best-known places in the solar system, with a fleet of rovers and spacecraft already on the surface, or en route to the surface, or orbiting overhead and taking remarkable photographs.