Images: A century of polar exploration

Thursday marked the beginning of the International Polar Year, a study of the effects of global warming at the poles. The study will be the first large-scale, coordinated investigation of the poles in 50 years.

Since the first International Polar Year in 1881, the poles have given scientists unique opportunities to study everything from climate change and prehistoric animals to the mysteries of the universe.

This is an aerial view of mountains and glaciers on Antarctica as seen on December 15, 2006.