International Dark Sky Designation

The Big Dipper Campaign

Cornwall Council is supporting the ‘Big Dipper’ campaign. This aims to raise public awareness of light pollution across Cornwall. The campain urges people to help conserve our starry dark night sky.

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Many outside lights, especially LED floodlights and security lights, can be too bright. They are installed in such a way that much of the light is directed up into the night sky. This contributes to the orangey-white sky glow above our towns and cities, which spreads out into the countryside.

With the nights drawing in the campaign aims to encourage property owners with outside lighting to assess how much lighting they have. It also hopes to encourage owners to ensure where possible that lamps are dipped downwards. The move is backed by Sir Martin Rees, Astronomer Royal, who said: 

"It's important that efforts are sustained to cut light pollution further so we can all marvel at the night sky wherever we may live. This campaign deserves wide support."

Residents and businesses do not need to struggle in the darkness, but by dipping lights we can reduce light pollution and retain the sense of wonder when we look up to the night sky. Poorly installed outside lighting can be detrimental to the quality of our dark skies. Many of the newer security lights being installed emit a very harsh blue-white light, which scatters further into the sky, blotting out our view of the stars. The impact is often made worse by the fact such units are angled outwards to increase the spread of light. A single, poorly installed floodlight can be seen for miles around. The night time environment is a crucial natural resource for people, wildlife and for the rural visitor economy which benefits from increasing public interest in astro-tourism.

The campaign is asking people to: 

  • Ensure lights point down and are fully shielded.
  • Only illuminate areas you need to and don’t leave lights on all night - use a timer or motion sensor.
  • Use lighting that is no brighter than necessary.
  • If possible don’t use LEDs emitting bright white/blue light, but rather warmer colours.

The power of a light is best characterised by its lumens output, usually listed on the packaging.  About 500 lumens is ample to illuminate a back garden.  Many LED products  also state the light’s colour temperature. Units of 3,000K and below, which produce a warm white colour, are less harmful to the night-time environment than 4,000K and 5,000K lights. 

For advice on minimising light pollution visit www.britastro.org/dark-skies or http://darksky.org/lighting/lighting-basics/. Further information on light pollution and interactive maps can be found at  www.nightblight.cpre.org.uk.

The International Dark-Sky Association has officially designated Bodmin Moor as an International Dark Sky Landscape. This follows an application prepared by Cornwall Council and Caradon Observatory (this version has updated links).

Recent light readings show the quality of the night sky over Bodmin Moor is amongst the best in the world. The purpose of achieving a designation is to capture the wide-ranging benefits of conserving this natural asset including:

  • Scientific advantages – enabling enhanced conditions for astronomy;
  • Educational outreach – facilitating both formal education (at all levels) and more informal activities;
  • Enjoyment and appreciation – improving quality of life and provide creative inspiration;
  • Health – promoting improved sleep patterns and reducing stress;
  • Wildlife – providing a more natural environment for both nocturnal and diurnal animals; and
  • Energy efficiency – reducing wastage from unnecessary or excessive lighting.

The Core Area is the extent of Bodmin Moor which is designated as an Area of Outstanding Natural Beauty (AONB). There is also a 2 mile Buffer Zone around this in which good lighting practice will also be encouraged and where communities are also expected to reap some of the benefits.

We want to encourage people who live and/or work on the Moor to manage lighting better and make sure it does what it needs to without harming the night sky.

Nevertheless we will not make anyone change their lights. We all need to see what we’re doing and feel safe as we go about our business. Too often however lighting is overly bright, needlessly spills upwards, poorly aimed and creates shadows – making it harder to see as well as being wasteful and harmful to the night sky. Well considered light can be much more effective.

We’ll produce a quick guide for Dark Sky friendly lighting for when fitting new lights or replacing old. We will encourage:

  • Installing lights that point down not up;
  • Turning lights off when they aren’t needed, maybe use a timer; and
  • Only lighting where you need to.

Both Cornwall Council street lighting and Highways England trunk road lighting have been assessed as part of this project. Cornwall Council lighting has been upgraded across the county as part of the Invest to Save scheme which has improved efficiency and reduced light pollution. We are also looking at where additional adjustments to street lighting would be appropriate on Bodmin Moor.

A list of frequently asked questions has been produced based on discussions with members of the public and other stakeholders.

Please email us at darksky@cornwall.gov.uk to subscribe to our electronic newsletters.  Past newsletters are available to download below:. Past newsletters are available to download below.

Good lighting practice is encouraged across Cornwall. There are also community-led efforts underway for an international designation for west Cornwall and the Isles of Scilly. View their Dark Skies Facebook page.

If you have any queries or comments you can email us at darksky@cornwall.gov.uk or write to us using the address below:

Dark Sky Bid, Cornwall Council, Planning Policy Team, Pydar House, Pydar Street, Truro  TR1 1XU