Can you wish upon a star?

2.00.12am UTC (GMT +0000) Sat 13th Jan 2007

With winter nights upon us, we should have more opportunities to gaze at the heavens. But wishing upon a star is becoming increasingly difficult as our skies are now not dark enough. On a totally dark night the Royal Astronomical Society estimates we should be able to see around 2,000 stars. But in many areas like Crawley pollution reduces visibility to a few dozen stars. Has the time come to call for the government to dim the lights?

Light pollution is the orange glow that can be seen at night for miles around cities, towns and even stretching into the countryside. It stops stars being visible to the naked eye, and over half of the population will never see the Milky Way from our homes.

It is caused by artificial light reflecting on airborne dust particles and water droplets. The main sources are from street lighting, security lighting and floodlighting of sports grounds, buildings and advertising signs.

Light pollution has also been blamed for a drastic fall in insect numbers. Insects attracted by increasing numbers of security and floodlights fly around all night and eventfully fall to the ground exhausted. This has consequences for birds and spiders that feed on these insects, with their numbers also in decline.

The UK is the second worst country for light pollution in. Proper lighting is essential for pedestrians and drivers, but local authorities have a major role to play in using effective lighting systems that do not cause light pollution.

In April this year light nuisance became subject to the same criminal law as noise and smells. But while this may stop security lights shining through neighbouring bedroom windows it does little to address the wider issue of tackling sky glow.

In the past the government has been criticised for failing to take the issue seriously. The parliamentary science and technology committee said the next generation of astronomers should be able to study the sky with the naked eye and without having to rely on computer generated images.

In the Czech Republic street lighting has been redesigned to control the spread of light and advertising boards are lit from above to stop light shining towards the sky. In regions of Italy all new public and private outdoor lighting, floodlighting in sports stadiums and the illumination of monuments must conform to strict standards to minimise light pollution.

Light pollution not only impairs our ability to see the stars, but it is also a waste of energy. The majority of electricity comes from fossil fuelled powered stations that cause air pollution and contribute to global warming.

Further information on the Campaign for the Preservation of Rural England (CPRE) light pollution report can be found at www.cpre.org.uk