1.  ABOUT THE COTSWOLD ASTRONOMICAL SOCIETY

  The Cotswold Astronomical Society (the Society) is a local society for amateur astronomers in an area centered on Cheltenham and Gloucester, though the Society has members in other parts of the United Kingdom and has close ties with societies and individuals in Australia, Canada and the United States of America. The Society numbers approximately 60 members of varying age groups and interests. Some members of the society work on serious programmes of astronomical research, including asteroid and neo astrometry, supernova patrols, and photometry, and astrophotography. In addition, the society frequently performs a "public outreach" function, providing talks, displays and observing sessions to local organizations (such as scouts, guides, schools), to encourage an appreciation of the delights of night sky and the science behind this.

2.  TOPICS FOR THE INQUIRY

  The following sections address the specific questions raised by the inquiry.

  2.1.  What has been the impact of light pollution on UK astronomy?

  There are four aspects to this question we think should be considered.

  2.1.1  Impact on professional astronomy

  Our impression is that little observational work is carried out from the UK by professional astronomers. There are many reasons for this, but historically encroaching light pollution has been a significant factor. The move of the Royal Greenwich Observatory from Greenwich to Herstmonceux, to Cambridge before disbandment was enforced due to deteriorating observing conditions at these sites. At Cambridge it was purely a management and technical operation for telescopes at remote locations. Many universities still operate large telescopes, and these are effective for training and instrument testing, but it seems likely that few published papers result from work on these. However there are reasons for this which are more due to the nature of astronomy research and lack of funding of facilities which are beyond the scope of this inquiry. With modern equipment and instruments we see no reason why significant professional research work could not be done from these shores with the current light pollution situation if there were a will to do this. This is attested to by the quality of observational work which is carried out by research amateur astronomers (see 2.1.3. below).

  2.1.2  Impact on the amateur astronomer

  Visual amateur astronomers are highly impacted by levels of light pollution in the UK. Enjoyment of the night sky from a dark location can only be enjoyed in a few remote locations in the UK. Superfluous lighting detracts from the ability to observe faint objects, and astro-photography which is one of the most popular pursuits is severely limited by sky glow throughout the UK. To develop dark adaptation required for the visual observation of faint objects requires at least 20 minutes without exposure to bright light, and in many light polluted areas full dark adaptation is never acquired.

  2.1.3  Impact on the researching amateur astronomer

  Strangely the advent of the astronomical CCD Camera priced within reach of the amateur has released many from the limitations of light pollution. By digital processing the effects of light pollution can either be subtracted from observations, or have little impact in the first place. Although the sort of programmes of work carried out by amateurs using CCD cameras take this into account, there is a wealth of observational work now being carried out that could not be done 10 or 15 years ago. Many amateurs are able to produce high quality observations of variable stars, double stars, galaxies, supernova, gamma ray burst optical counterparts, asteroid and near earth objects, comets, as well as the planets of our solar system. Many of these observations are coordinated by UK bodies such as the British Astronomical Association and are used by professional astronomers. Amateurs are able to monitor objects over extended periods of time (years or decades), which is something that the nature of professional research does not allow. However if professionals wished, they could now do much interesting observational work from UK sites.

  2.1.4  Impact on the general public

  There is a great interest in astronomy by the general public and this is attested to by the attendances at public observing sessions, open days and star parties. Children in particular can get "turned on to" science by experiencing stars, planets, nebulae, and galaxies at first hand. However, as light pollution encroaches their own back gardens many of these are difficult or impossible to experience. There is a particular joy to be had when children see the milky way for the first time, and realize this is our own galaxy, but in any urban area the milky way is all but invisible.

  2.2.  Are current planning guidelines strong enough to protect against light pollution?

  The simple answer to this is no. There are no specific controls that appear to relate to the control of lighting to prevent light pollution.

  In a recent case in Cheltenham a garage set up a searchlight beam that sweeped the sky, causing significant light pollution and distress to local observers. The only planning regulation to control this was as its use as an advertisement, for which planning approval is required. The planning meeting considered an application for this search light beam and rejected it. However, the garage in question circumvented the requirement for permission by mounting the search light on a truck and as it was no longer a fixture the planning control did not apply. Only by concerted public and media pressure was the garage persuaded to switch this light off.

  Also in Cheltenham the construction of a superstore area behind a members house with continuous all-night lighting which flooded the members garden and observatory caused the member give up astronomy all together. There seemed to be no consideration for local residents when this lighting scheme was adopted.

  In Gloucester lighting of sports fields is a concern. High power lighting of sports fields is becoming common as leisure centres and schools try to make more use of their facilities in the evenings in winter. There seems to be little control over the design and implementation of such lighting schemes causing glare and distraction to local observers.

  Domestic security lighting continues to cause problems. These lights tend to be over-powered for their need, and inappropriately installed causing glare and prevent observations in some cases. A light many houses away can cause difficulties for observers, and owners are not always sympathetic to requests to turn-off or redirect their lights.

  A recent trend in garden lighting is a cause for concern. Although on the whole these are low wattage they do tend to be omni-directional or even upward facing for the lighting of trees or bushes. Garden lighting is likely to be the next "big thing" in gardening and garden design, replacing water features and decking. Control of this at an early stage would be useful.

  A common misconception is that if lighting is used early in the evening this will not affect astronomers. Whilst it is true that many astronomers do observe late and through the night when most are asleep, it is also the case the many objects can only be observed in the early evening. This is certainly true of comets as they approach the Sun, and the inferior planets (Mercury and Venus), but with the rotation of the heavens it will always be the case that there will be certain areas of the sky that will only be available at that time of day, and this may be the only time that data may be obtained.

  Current planning regulations do not seem to control the pattern of light. There seems to be no control of the spill of light from one property into another. Light spread upwards can only go outwards into space, and cause glare and skyglow. Hoods on lights to ensure the light only goes downwards would be of great benefit in reducing light pollution.

  2.3.  Are planning guidelines being applied and enforced effectively?

  Our experience in Cheltenham is that when an infringement has been noted the planning authority does attempt to enforce the regulations. However, regulations appear to be inadequate to control the worst of these.

  2.4.  Is light measurable in such a way as to make legally enforceable regulatory controls feasible?

  The pattern of light from a lamp is easily measurable, and the spill of lighting into unintended areas could be easily determined. The intensity of illumination can be measured using light meters. The illumination could be measured in flux per square meter and a maximum determined for area lighting.

  For directional beams a lower limit could be considered (taking into account beam width and direction).

  For temporary lighting or "light shows" a licence should be required.

  Search lights for search, rescue and policing should obviously be exempt when used for short term purposes.

  2.5.  Are further controls on the design of lighting necessary?

  Yes, controls on exterior domestic lighting which may constitute a nuisance are required. Where planning applications are made for buildings or lighting structures of any nature, exterior lighting design should be required to be specified.

  3.  Concluding Remarks

  New road and street lighting are generally effective in minimizing light pollution, but there does seem to be a trend to increase lighting in areas where historically lighting would not have been used. There are still many areas with old fashioned light fittings that are not `friendly' and a programme to replace these with modern fittings is needed.

  As towns expand and urbanization increases, light pollution impacts more and more of our population.

  Unless we can stop and preferably reverse this trend in the future we will loose our appreciation of our place in the universe. The night sky is a natural resource for all to enjoy, whether for the natural beauty, the thrill of discovery, or the pursuit of scientific investigation.

12 April 2003