507687main_image_1831_946-710.jpg

Taken by the Expedition 26 crew, this photograph shows two of China's most populous cities at night. Located in the northern part of the country, Beijing and Tianjin are estimated to house, together, nearly 20 million people, with 12 million in the Beijing metropolitan area and over 7 million in Tianjin.

"The dark regions surrounding the well-lit urban areas are mainly agricultural fields, with wheat and corn being the major crops," NASA explained. "Beijing is one of the recognized ancient capital cities -- and the current capital -- of the People's Republic of China. The regular grid pattern of the city is clearly visible at lower upper right; concentric rings of major roadways around the city center have been added as the metropolitan area has expanded. Tianjin is a major trade center with connection to seaports on the Bohai Gulf. The city was established following the integration of the Grand Canal of China, a major artificial waterway extending from Beijing southwards to Hangzhou."

(Click on the image to view a larger version.)

Image: NASA.

View more Pictures of the Day.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.