NASA Photo of the Week

Satellite image of Canary Island eruption.

City light clusters give an immediate sense of a community's relative size. Demographers have used nighttime satellite images to make estimates of city populations, especially in the developing world where growth can be sudden and difficult to document.

Astronauts orbiting aboard the International Space Station (ISS) pass over the nighttime portion of the world about 15 times each day.

And the night skies above populated areas frequently appear as a network of lights or a patchwork of illumination from 240 miles above.

The image to the right was taken on the evening of September 29, 2011, as the ISS looked northeastward across the American Midwest.

The artificial light of human settlements glowed with a yellow tinge, and appeared most dense around the major metropolitan areas of St. Louis and Chicago.

Lights generated by illumination and traffic on interstate highways appear to converge on large cities, much like wheel spokes around a central hub.

The eerie green glow of the aurora borealis showed brightly over Canada to the north, even vividly reflecting off the Earth’s surface and cloud tops below.

One of the solar panels powering the ISS appears across the top of the image. The NASA camera also captured a lightning strike illuminating clouds from a cluster of thunderstorms near New York City over parts of southern New England.

This image is one of a long series of stills that has been converted into a breathtaking time-lapse video. The brief time-lapse movie gives a sense of flying across the Midwest at night.

Full story and image: NASA