ISS026-E-6255 Click the photo number to access all resolutions available and the database record.
Astronauts on the International Space Station (ISS) observe and photograph numerous metropolitan areas when they are illuminated by sunlight, but the extent and pattern of these areas is perhaps best revealed at night by city lights. The surrounding darkness of the desert presents a stark contrast to the brightly lit street grid of the developed area. The Vegas Strip is reputed to be the brightest spot on Earth due to the concentration of lights on its hotels and casinos. The tarmac of McCarran International Airport is dark by comparison, while the airstrips of Nellis Air Force Base on the northeastern fringe are likewise dark. The dark mass of Frenchman Mountain borders the city to the east.
The acquisition of focused nighttime images requires astronauts to track the target with the handheld camera while the ISS is moving at a speed of more than 7 kilometers per second (over 15,000 miles per hour) relative to the Earth’s surface. This was achieved during ISS Expedition 6 using a homemade tracking device, but subsequent crews have needed to develop manual tracking skills. These skills, together with advances in digital camera technology, have enabled recent ISS crews to acquire striking nighttime images of the Earth (such as this recent image of the Nile River Delta).
