AstroPicture of the Day: North Korea highlighted by its own darkness

Can you find the border?

A Nasa Earth Observatory spokesman said at the time the picture was taken:

‘North Korea is almost completely dark compared to neighboring South Korea and China. The darkened land appears as if it were a patch of water joining the Yellow Sea to the Sea of Japan. Its capital city, Pyongyang, appears like a small island, despite a population of 3.26 million (as of 2008). The light emission from Pyongyang is equivalent to the smaller towns in South Korea. Coastlines are often very apparent in night imagery, as shown by South Korea’s eastern shoreline. But the coast of North Korea is difficult to detect.’