August 26, 2003
The above photo was taken at sunrise looking toward the west on the island of Maui, Hawaii. It shows the triangular shadow of a volcano, Haleakala, against a backdrop of low clouds over western Maui. A portion of the shadow is also cast on the sky. This can happen when dust in the atmosphere, outside of the shadow, scatters sunlight. Inside of the shadow, scattered sunlight is absent, thus the shadow appears darkened. Typically, for this effect to be seen, there must be quite a bit of dust or other aerosols overhead. It should be noted that even flat-topped mountains will cast a triangular shadow. The meaning of the name of the Haleakala, is "house of the Sun" in Hawaiian, as its shadow so often looks like a house. See also the Earth Science Picture of the Day for July 21, 2003.