On bright, sunny days, the rising sun casts shadows across the pond’s snowy surface, dividing the vast expanse into pale blue sections set apart from the white. Sometimes, too, the snow deep inside a mound or plowed bank is blue, a phenomenon once again caused by how the light interacts with its surroundings.

When light shines on snow, all the colors of the spectrum bounce off, which accounts for why snow appears to us as pure white. The bands of white snow across the pond are reflecting the greatest amount of light, while the blue bands reflect the light coming at them from a different angle. If that same light, however, passes through some of the snow particles, a few of the wavelengths of the color spectrum are absorbed while others are not. Thus, snow often appears blue because all the other colors are absorbed. On the snow’s outermost layers, the blue is pronounced with no gradations, or subtle changes, in its hue. The deeper into the snow we go, though, the more it varies depending upon how many snow particles it bounces against. As the light travels more deeply into a snow bank or deep drift, every grain of snow absorbs some of the spectrum’s red light, and the denser the snowpack, the more red light is absorbed, causing the light that remains to become bluer. The heavier the snow, the more blue light it will reflect, and the lighter and drier the snow is, the whiter it will appear.

Not only does the early morning sunlight turn parts of the pond’s snow blue, it also manifests itself differently from that point on throughout the day. If there are tracks on the snow or if it the wind has drifted it into small mounds that dot its surface, shadows form in the direction away from the sun’s approach, giving the entire surface a mottled look. Even the tiniest depression in the snow takes part in this process, and appears to be composed of half dazzling, white light and half pale blue light. In the late afternoon, the scene is reversed, with the shadows shifting to the east as the sun’s light weakens above the tree line. It is an ever-changing canvas onto which a bald eagle descended, yesterday morning, that seemed to materialize out of the sky.

Appearing from this distance too large to be a crow, the bird’s characteristic markings ”“ the white head and tail and large yellow talons ”“ loomed large through my field glasses, and I stared in awe as the magnificent creature moved slowly across the pond. It stopped several times and tilted its head down very close toward the surface, and the only conclusion I was able to draw from this was that it was hearing or seeing fish through the ice, for it seemed to be moving around in an area where, just the day before, people had cleared the snow away for drilling. The eagle walked back and forth across the same spot several times, and then, without warning, its great dark wings opened and carried it almost effortlessly to the top of a dead pine on the farther shore, the white of its tail-feathers flashing in the sunlight.

Once again, had I not been here or been attentive enough to the outdoor goings-on, I would have missed this. For nature rarely prepares us for what she has in store, never sends calling cards to announce her presence, be it in the form of a breathtaking sunset, deer grazing close to a back porch, or an eagle landing on a frozen pond in winter. It is incumbent upon us to try as much as we can to keep an eye or an ear out to whatever is going on out there. For it’s been my experience that, sooner rather than later, we are rewarded with a sight or a sound that instantly changes our status from one who wishes he or she had heard or seen something wondrous to one who has.

— Rachel Lovejoy, a freelance writer living in Lyman, who enjoys exploring the woods of southern Maine, can be reached via email at rachell1950@yahoo.com.