Opposition Effect Over Northeastern Brazil

January 19, 2008


Provided by: Fabiano Diniz
Summary Author: Fabiano Diniz, Jim Foster

During a flight back from my vacation in the northeastern Brazil, I happened to notice the opposition effect shown above. At the time the photo was taken, the altitude of the jet aircraft was approximately 39,000 ft. (12,000 meters). Shadows from trees and other irregularities on the terrain cannot be easily detected if the Sun is directly behind the viewer or, in this case, the camera. Thus, the whitish spot on the scene above marks the antisolar point, where all of the shadows are hidden by the objects producing them. Away from the antisolar point, the shadows are slightly more obvious and a darker scene results. The opposition effect is caused solely by the reflection of sunlight. The presence of water droplets, ice crystals or dust particles is not required. Photo taken on July 25, 2007.