Photo of the Day: Exquisite Earth

"Mushroom cloud of stone erupts in the Ténéré desert, remnant of its watery past. This pedestal rock began as a mass of pebbly sandstone. Its sculptors were cycles of hot and cold, wet and dry, as well as blowing sand, which caused the sloughing off of shards scattered at the base."

(Text and photograph from "Journey to the Heart of the Sahara," March 1999, National Geographic magazine)