The Tien Shan mountain range is one of the largest continuous mountain ranges in the world, extending approximately 1,550 miles (2,500 kilometers) roughly east-west across Central Asia. This image taken by the Expedition 27 crew aboard the International Space Station provides a view of the central Tien Shan, about 40 miles (64 kilometers) east of where the borders of China, Kyrgyzstan, and Kazakhstan meet. The uplift of the Tien Shan, which means celestial mountains in Chinese, like the Himalayas to the south, results from the ongoing collision between the Eurasian and Indian tectonic plates. The rugged topography of the range is the result of subsequent erosion by water, wind and, in the highest parts of the range, active glaciers. Two high peaks of the central Tien Shan are identifiable in the image. Xuelian Feng has a summit of 21,414 feet (6,527 meters) above sea level. To the east, the aptly-named Peak 6231 has a summit 6,231 meters, or 20,443 feet, above sea level. Image Credit: NASA