Photo of the Day 1 December 2008

Petroglyphs, Aïr Mountains Mountains, Niger, 1999
Photograph by George Steinmetz
These 2,500-year-old petroglyphs, portraying figures with tulip-shaped heads and hourglass bodies, mark an ancient human presence in the Sahara desert’s Aïr Mountains. Despite the extreme temperatures and sparse rainfall characterizing these arid landscapes, more than one billion people eke out a living in desert regions today.