Stargazers chart Peak District light pollution
Light pollution in the Peak District is being measured with the public's help.
The park authority wants residents and visitors to study the night sky and record how many stars they see.
Organisers are focusing on the distinctive constellation of Orion, asking observers to compare what they see with examples on their website.
By judging how many stars are visible in each report, the authority aims to compile a picture of how much artificial light is escaping.
The first phase of the project is under way, with a second part running from 28 January until 2 February.
Jane Chapman, the authority's head of environment, heritage and recreation strategy, said: "Light pollution not only affects our enjoyment of the night sky, it wastes energy and has an impact on the wellbeing of people and wildlife.
"Unfortunately light pollution is increasing each year, so unless we act now future generations may grow up never experiencing a truly dark night sky."
She added that information gathered would help formulate future policy.