The biggest shadow on Earth is the shadow of Earth. How Earth’s shadow will fall on the moon’s face — and how to see Earth’s shadow any clear evening .I`m asking you to imagine the biggest shadow you’ve ever seen.
Tall buildings cast shadows. Mountains cast shadows. On an overcast day you’re standing in the shadow of a cloud bank that may be tens or even hundreds of kilometers long. But the biggest shadow on Earth is the shadow of Earth. Unless you live at one of the poles, you’re inside the Earth’s shadow for part of every 24-hour day. In other words, night is a shadow.
Just like your own shadow, the shadow of Earth extends opposite the sun. Sometimes Earth’s shadow falls on the moon in a total lunar eclipse . . . like the one many people will see on November 28. Earth always keeps its shadow — because nothing big enough ever gets close enough to shade the Earth. Even during total eclipses of the sun, when the moon’s shadow falls on our world, that lunar shadow is just a little black dot sweeping across the face of the larger Earth.
So don’t forget to watch for Earth’s shadow during 28 night’s lunar eclipse. Also, you can see Earth’s shadow on any clear evening. It’s a curved line of darkness ascending in the eastern sky. It’s a deep blue color — very different from the fading blue of the twilight sky. As the sun sinks below the western horizon, Earth’s shadow rises in the east — until we’re submerged in it — and it’s night.