|
|
The Shadow of the Earth in the Smog
Usually, while we are watching a sunset, we're looking west to enjoy the red and orange colors of the setting Sun. The longer wavelengths of the Sun's light, the reds and oranges, tend to come through the atmosphere better than do the blues which
tend to get scattered in all directions, including back toward the
Sun. That's why the setting Sun looks red or orange. And that's why
the sky looks blue. But if, at the time of the sunset, you look east
instead of west, you can see the blue light that has been scattered
from the sunsets seen by others from farther east. And if you look
east just after the Sun has gone down, you can often see the shadow
of the Earth in the smog. The Earth's shadow will be seen as blue against the
pink of the sunlit smog above it. And as the Earth turns, and the
Sun seems to sink farther and farther below the horizon, the blue shadow of the Earth will appear to climb higher and higher through the pink of the sunlit smog. And if you ever have the opportunity to see this from some thirty-five thousand feet up
in an airplane flying west across the continent, you'll see how spectacular
the colors can be.
|
