On the edge of the Kalahari Desert in Namibia, sand dunes are encroaching onto once-fertile lands in the north. Healthy vegetation appears red in this image; in the center, notice the lone red dot. It is the result of a center-pivot irrigation system, evidence that at least one optimistic farmer continues to work the fields despite the approaching sand.
This image was acquired by Landsat 7's Enhanced Thematic Mapper plus (ETM+) sensor on August 14, 2000. This is a false-color composite image made using near infrared, red, and green wavelengths. The image has also been sharpened using the sensor's panchromatic band.