Whirlpool in the Air, Greenland

This image shows a spinning formation of ice, clouds, and low-lying fog off the eastern coast of Greenland.

This image was taken on 5/14/2001.

Yellowknife Wetlands, Canada

This area lies near the town of Yellowknife in northern Canada. Every black spot in this image is a shallow lake. These lakes formed in grooves in the landscape that were carved by glaciers during the last Ice Age.

This image was taken on 7/3/2001.

San Diego, California, USA

This natural-color image shows the city of San Diego. Water is blue, city areas are gray and white, vegetation is green, and the dry hills surrounding the city are reddish-brown.

This image was taken on 2/9/2002.