If you have the opportunity, take a walk in the woods or in a park or even around a city block on a winter night when the moon is full and there's a good covering of snow on the ground. The next full moons are due Jan. 4 and Feb. 3. You'll notice the sparkling light on the snow and the wondrous silhouettes of trees and their dark shadows. Most anyone embarking upon this mini adventure will hope to hear the hoot of a great horned owl. Yet, it's the cold silence and the moonlight that really restore our minds.

No other celestial object is held in greater affection than the moon — save for our closest star, the sun. The moon is linked to romance. We find beauty when watching all phases of the moon, but during the full moon we see face-like features in the light and dark patterns of its disk.

Both the words "month" and "moon" derive from the same root, which means "to measure." Our most important tool for measuring time — the calendar — was designed around the moon's phases. The average month of 30 days coincides closely with the 29 days, 12 hours and 44 minutes it takes for the moon to make a complete rotation around the Earth. And the period between phases — from one full moon to the next — is close to 29 ½ days.

The distance to the moon is about 239,000 miles, and its reflected sunlight takes about 1.3 seconds to reach us. Full moonlight outshines four-fifths of the stars we see on a moonless night. Despite the brilliance of the full moon, it shines with less than 1/400,000 the light of the sun.

Jim Gilbert's Nature Notes are heard on WCCO Radio at 7:15 a.m. Sundays. His observations have been part of the Minnesota Weatherguide Environment Calendars since 1977, and he is the author of five books on nature in Minnesota. He taught and worked as a naturalist for 50 years.