Satellite images reveal life on Earth at night
They look like an array of twinkling lights – but represent tens of millions of people getting on with their life on Earth.
New night-time satellite images released by Nasa show the West Midlands as a beacon of brightness.
It represents a ball of light second only in size to London, part of a band that stretches north to the heavily populated areas of Greater Manchester.
More than five million people live in the West Midlands, making up more than 10 per cent of Britain's total population.
But in this satellite image, the region is shown as little more than a speck of yellow, with nothing but blackness to the west, representing the rural expanse of Shropshire and Mid-Wales.
The images show the Earth as they have never been seen before, and reveal in total clarity just how our cities dominate.
Taken by a Nasa-NOAA satellite, which was launched last year, they are a result of a sensor dubbed the Visible Infrared Imaging Radiometer Suite (VIIRS), which is sensitive enough to detect the nocturnal glow produced by Earth's atmosphere and the light from a single ship in the sea.
Unlike a camera that captures a picture in one exposure, the day-night band produces an image by repeatedly scanning a scene and resolving it as millions of individual pixels.
The images show just how concentrated the United Kingdom's population is on England, with London, the Midlands and the North West glowing bright. Other areas of the country are largely dark, although Newcastle and the North East stands out, as does Glasgow and South Wales. Ireland is largely dark, but Paris dominates France and the industrial heart of Holland and Germany are clear to see.
Other images released by Nasa show the Nile River bathed in city lights. A map of the United States shows the populated East Coast illuminated and light from fishing boats can also be pinpointed. The satellite also captured the glow from natural sources including moonlight, northern lights and naturally-occurring fires.
After Superstorm Sandy made landfall in late October, hard-hit New Jersey, lower Manhattan and the Rockaways appeared dark in the satellite images compared with surrounding areas – the result of power cuts.
With its night view, VIIRS is able to detect a complete view of storms and other weather conditions, such as fog.
Steve Miller, an academic at NOAA's Colorado State University Cooperative Institute for Research in the Atmosphere, says the new technology provides scientists with a valuable new research tool.
