Earth Observations taken by the Expedition 22 Crew

ISS022-E-078463 (28 Feb. 2010) ---The Houston metropolitan area at night is featured in this image photographed by an Expedition 22 crew member on the International Space Station. Houston, Texas has been called the ?energy capital of the world? due to its role as a major hub of the petroleum and other energy resource industries. The image is oriented with north toward the top. The Houston metropolitan area covers almost 2,331,000 hectares (approximately 9,000 square miles) along the southeast Texas coastline, with an average elevation of 13 meters (approximately 43 feet) above sea level and a population of over 5 million (2006 US Census estimate). The Houston metropolitan area is also noteworthy as being the largest in the US without formal zoning restrictions. This has lead to a highly diverse pattern of land use at the neighborhood scale; nevertheless, more general spatial patterns of land use can be recognized in remotely sensed data. This is particularly evident in night time photography of the urban area taken by crew members onboard the space station. The image depicts the roughly 100 kilometers (approximately 62 miles) east-west extent of the Houston metropolitan area. Houston proper is at center, indicated by a ?bull?s-eye? of elliptical white to orange-lighted beltways and brightly lit white freeways radiating outwards from the central downtown area. Suburban and primarily residential urban land use is indicated by both reddish-brown and gray-green lighted regions that reflect a higher proportion of tree cover and lower light density. Petroleum refineries along the Houston Ship Channel are recognized by densely lit areas of golden yellow light. Rural and undeveloped land circles the metropolitan area, and Galveston Bay to the southeast (lower right) provides access to the Gulf of Mexico. Both types of non-urban surface appear dark in the image.