An astronaut aboard the International Space Station took this nighttime panorama while looking north across Pakistan’s Indus River valley. The port city of Karachi is the bright cluster of lights facing the Arabian Sea, which appears completely black. City lights and the dark color of dense agriculture closely track with the great curves of the Indus valley. For scale, the distance from Karachi to the foothills of the Himalaya Mountains is 1,160 kilometers (720 miles). This photograph shows one of the few places on Earth where an international boundary can be seen at night. The winding border between Pakistan and India is lit by security lights that have a distinct orange tone. Astronaut photograph ISS045-E-27869 was acquired on September 23, 2015, with a Nikon D4 digital camera using a 28 millimeter lens, and is provided by the ISS Crew Earth Observations Facility and the Earth Science and Remote Sensing Unit, Johnson Space Center. via NASA Earth Observatory Read more: <a href="http://earthobservatory.nasa.gov/IOTD/view.php?id=86725&eocn=home&eoci=iotd_title" rel="nofollow">earthobservatory.nasa.gov/IOTD/view.php?id=86725&eocn...</a>

An astronaut aboard the International Space Station took this nighttime panorama while looking north across Pakistan’s Indus River valley. The port city of Karachi is the bright cluster of lights facing the Arabian Sea, which appears completely black. City lights and the dark color of dense agriculture closely track with the great curves of the Indus valley. For scale, the distance from Karachi to the foothills of the Himalaya Mountains is 1,160 kilometers (720 miles). This photograph shows one of the few places on Earth where an international boundary can be seen at night. The winding border between Pakistan and India is lit by security lights that have a distinct orange tone. Astronaut photograph ISS045-E-27869 was acquired on September 23, 2015, with a Nikon D4 digital camera using a 28 millimeter lens, and is provided by the ISS Crew Earth Observations Facility and the Earth Science and Remote Sensing Unit, Johnson Space Center. via NASA Earth Observatory Read more: <a href="http://earthobservatory.nasa.gov/IOTD/view.php?id=86725&eocn=home&eoci=iotd_title" rel="nofollow">earthobservatory.nasa.gov/IOTD/view.php?id=86725&eocn...</a>

ISS028-E-029679 (21 Aug. 2011) --- A night time view of India-Pakistan borderlands is featured in this image photographed by an Expedition 28 crew member on the International Space Station. Clusters of yellow lights on the Indo-Gangetic Plain of northern India and northern Pakistan reveal numerous cities both large and small in this photograph. Of the hundreds of clusters, the largest are the metropolitan areas associated with the capital cities of Islamabad, Pakistan in the foreground and New Delhi, India at the top?for scale these metropolitan areas are approximately 700 kilometers apart. The lines of major highways connecting the larger cities also stand out. More subtle but still visible at night are the general outlines of the towering and partly cloud-covered Himalayan ranges immediately to the north (left). A striking feature of this photograph is the line of lights, with a distinctly more orange hue, snaking across the central part of the image. It appears to be more continuous and brighter than most highways in the view. This is the fenced and floodlit border zone between the countries of India and Pakistan. The fence is designed to discourage smuggling and arms trafficking between the two countries. A similar fenced zone separates India?s eastern border from Bangladesh (not visible). This image was taken with a 16-mm lens, which provides the wide field of view, as the space station was tracking towards the southeast across the subcontinent of India. The station crew took the image as part of a continuous series of frames, each frame taken with a one-second exposure time to maximize light collection ? unfortunately, this also causes blurring of some ground features. The distinct, bright zone above the horizon (visible at top) is produced by airglow, a phenomena caused by excitation of atoms and molecules high in the atmosphere (above 80 kilometers, or 50 miles altitude) by ultraviolet radiation from the sun. Part of the ISS Permanent Multipurpose Module, or PMM, and a solar panel array are visible at right.