6. Earth's City Lights (October 23, 2000)
Twinkle, twinkle, little cities. A spacecraft originally designed to look at clouds by moonlight was employed to make this view of Earth's artificial lighting.
Showing urbanization rather than population, this light data has been used by NASA scientists to analyze urban sprawl and the technological advancement of the world's cities.
The United States interstate highway system can be seen as a fine lattice, while the Nile River is a bright thread, thanks to the cities on its shores.
The image also reveals Western Europe "out-glowing" China, the Trans-Siberian Railroad stretching across Asia, and the bright arc of Japan hovering above a mostly dark Australia.
(View this image at maximum size.
Image by Craig Mayhew and Robert Simmon, NASA GSFC, based on DMSP data, courtesy Earth Observatory