To an observer in space, humanity's footprint on the surface of the Earth is large and varied. Astronauts circling the Earth have the perfect vantage point, taking in whole regions at once.
São Paolo, Brazil
This image, taken April 12, 2003, shows the sprawling urban footprint of São Paulo, Brazil, South America's largest city with roughly 17 million people. The different colors (pink, white and gray) define different types and generations of streetlights. The port of Santos, on the right side of the photograph, is also well defined by lights.
Mecca/Jiddah, Saudi Arabia
The rapid growth in Jiddah and Mecca in Saudi Arabia can be mapped from the lighting patterns. The road connecting them, heavily used by pilgrims of several faiths on their journey between the two cities, stands out as a bright string in the surrounding dark desert.
Cities from different regions of the Earth can be identified by differences in their lights. Japanese cities glow a cooler blue-green than other regions of the world. Newer developments along the shore of Tokyo Bay, as shown in this photo taken Feb. 5, 2008, are characterized by orange sodium vapor lamps, while the majority of the urban area has light-green mercury vapor lamps.
Los Angeles, California
After sunset, the borders of the City of Angels are defined as much by its dark terrain as by its well-lit grid of streets and freeways. In the north, Hollywood is nestled against the south side of the Santa Monica Mountains. On the coast, Los Angeles International Airport and the port facilities at the former Long Beach Naval Shipyards are bright spots. Finally, even at night, the bright lights of Disneyland in Anaheim are a standout feature.
New York City, New York
Known as the City that Never Sleeps, New York City is the largest and brightest metropolitan area along the East Coast. This image was taken from a vantage point well to the northeast of the coast. With the camera pointed westward back towards the city, it gives a perspective that is highly distorted but still recognizable.
Seoul, South Korea
In this photo of Seoul, South Korea, taken Dec. 25, 2004, major roadways and river courses (such as the Han River) are clearly outlined by street lights, while the brightest lights indicate the downtown urban core (center of image) and large industrial complexes. Very dark regions in the image are mountains or large bodies of water.
Lights along the Nile
City lights captured by the photo taken April 11, 2003, define the Nile River Valley as it snakes across the Egyptian desert. The cities of Naj' Hammadi, Qena and Luxor shine the brightest. Communities in the hillsides create a thin border along either side of the valley. Similar strips line the Nile itself. Most of Egypt's population, and most of the country's arable land, occupies the Nile River Valley.
Ciudad Juárez, Mexico and El Paso, Texas
In this photo, taken April 7, 2003, the more densely populated Ciudad Juárez, Mexico, is clearly separated from El Paso, Texas, by the Rio Grande. These border cities illustrate different patterns, suggesting cultural influences on the development and growth of cities and infrastructure.
This nighttime view of the British capital captured Feb. 2, 2003, offers unique insight into the city's urban density and infrastructure. Interpreting the brightest areas as the most populated, the population density drops off rapidly from the bright urban center until it reaches the Orbital roadway. Beyond lie isolated bright areas marking the numerous smaller cities and towns of the region and as far southeast as Hastings on the coast.
In many North American cities, older neighborhoods have less regular street patterns and light-green mercury vapor lighting, while newer cities, like Denver, have street patterns aligned to the compass directions and use orange sodium vapor lighting. The major Denver street patterns, as seen in this photo taken on Jan. 31, 2008, are rectilinear, aligned north-south and east-west.
Buenos Aires, Argentina
Taken very early on the morning of Feb. 8, 2003, this remarkably clear image shows the lights of Argentina's capital city. The brightest area is the old part of the city centered on the port and the presidential palace, the Casa Rosada. The blackest part of the scene is the River Plate, the great estuary of the Atlantic Ocean on which this port city is located.
All photos courtesy NASA
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