If you look toward the eastern horizon on a clear evening just after sunset, you can often see the Earth’s shadow projected against the sky.  It looks like a greyish-blue band stretching along the horizon, and as the sun drops further below the horizon, the band gets correspondingly thicker until it fades away as the sky darkens.

This image of the Earth’s shadow is a little different.  It was taken from 10,000 feet at the top of Hawaii’s Haleakala Crater, high enough that we were above the clouds in the foreground.  The picture was taken shortly before the sun had set, but the Earth’s shadow against the sky is visible nevertheless--the grey-blue area in the middle of the image, just above the clouds.  In addition, the shadow is not a uniform band, and the peak of Haleakala itself is can be seen in the shadow’s shape.

Image details:  1/60-second exposure at ISO 400 with a Canon 400D camera and zoom lens at 49 mm.

August 2007