Dam Big

Upon completion in 2009, the Three Gorges Dam along China’s Yangtze River will be the world's largest hydroelectric power generator and one of the few man-made structures so enormous that it's actually visible to the naked eye from space. NASA's Landsat satellites have provided detailed, vivid views of the dam since construction began in 1994.

Environmentally, geographically and risk controversial, the sheer size and power of the dam is mind-boggling. At a construction cost of at least $625 billion, it is roughly 1.4 miles (2.3 kilometers) long and 607 feet tall, five times larger than Hoover Dam on the Arizona-Nevada border.

Here's a dramatic Landsat video that demonstrates the changes in landscape over a 19 year period.

(via EurekAlert)