article_snippet: Anyone who has flown back from a holiday at night will have marvelled at the twinkling blanket of lights that cover towns and cities after dark.
article_snippet: It shows concentrations of light in major towns and in the distance a green light that looks like the Northern Lights glows .
article_snippet: It shows concentrations of light in major cities and towns and in the distance, on the curvature of the Earth, a green light that looks like the Northern Lights glows.