The darkness of night allows astronauts to see just how dense New York City and the surrounding area is.

An astronaut aboard the International Space Station (ISS) centered this night photograph on the most brilliant group of lights in the northeast US: New York City and Newark, NJ (at image center) lie at the center of the string of city lights stretching from a distance of 325 km (200 miles) from Philadelphia, PA (at image lower left) to Hartford, CT (top right). The characteristic shape of Long Island, during night and daylight passes may be the most recognizable feature to an astronaut.
Lesser night-light intensity parallels lower population densities--well illustrated on Long Island--where the progressive decline of population density away from cores of the largest cities. This is a phenomenon well-known to urban geographers.
Yet lower population densities appear in the southern counties of New Jersey in a dispersed settlement pattern that stretches 60 miles to Barnegat Bay (at image lower left). Here the barrier island is defined by narrow shoreline developments (at image lower left margin). Rural areas (at image top left) with the lowest populations have almost as few lights as the Atlantic Ocean (at image lower right).
The network thin lines of highways and main roads--difficult to see in daylight images--radiate outward from the major cities (Philadelphia is the best example in this view). One of the brightest lines is Interstate 95 that crosses the entire image, from a point west of Philadelphia, through New York--where it is drowned out New York city lights--and along the coast of Long Island Sound to New Haven and further east.

Image credit:
NASA/Johnson Space Center