Light pollution

Light pollution

Spoiling our views of the heavens

The effects of light pollution on how we see night-time skies are dramatic. From a light-polluted town or city, it’s possible to see perhaps 200 stars, however from a dark sky site, it’s possible to see as many as 3000 stars without any visual aid on a moonless night.

You can often readily see the effects of light pollution yourself, on some nights the skies glow orange caused by the inefficient sodium-vapour street lights illuminating the clouds above. On clear nights that light dilutes the skies meaning starlight is washed out and fewer stars being visible.

angles of lighting and their effect on the skies
The correct use of lighting helps us to see the stars

Nature needs the night

Recent studies have identified light pollution as having a growing significant impact on our environment. Adverse effects have been found not just in humans, where light affects sleep patterns and can even lead to cancers, but in nature too.

For example, have you recently heard bird-song in the middle of the night? While LED lighting offers better efficiency, the use of bright white light is leading to confusion in both nocturnal and diurnal (daytime) animal behaviour. Indeed, light pollution is causing adverse knock-on effects throughout nature’s ecosystems.

White LED floodlights in Kielder Village
Even protected places are at risk! Photo of white LED floodlight in Kielder Village

Taking simple steps will help

There is a simple rule to follow — use light only where and when you need it.

Consider your own impact on your local environment, in particular at home but also your place of work. Does the floodlight you have in the back garden need to illuminate your neighbours upstairs windows or roof? Should it always be left on, or only when people need it?

Adjusting fittings to direct light downwards is a quick and easy fix, and most lights can be put on a timer or fitted with an inexpensive motion detector.

Poorly angled wrong colour temperature LED lights
Example of poor LED direction and wrong colour temperature – photo by Richard Darn

How bad is light pollution near you?

See for yourself just how bad (or good!) light pollution levels are near you on our interactive light pollution map, which comes in especially handy if you are planning a stargazing trip and looking for dark locations!

 

Contact your local MP

Perhaps the most significant action you can take is to ask your MP to join the All Party Parliamentary Group for Dark Skies. Our website makes it easy for you to do so! Simply enter your postcode to find your MP and submit our pre-populated form to send them an email with your instructions!

Locations on our website

To give you an idea of what to expect all stargazing events and locations on this website have been categorised based on light pollution data obtained via this recent light pollution study to give an approximate indication of how dark the local sky conditions might be on a moonless night (when there is a moon in the sky conditions will be similar to “urban” no matter the location).

Dark site

dark site light pollutionDark sites represent the very darkest of locations and are therefore the very best places to go stargazing. From these sites, the brighter and darker regions of the Milky Way are clearly visible and the glow of light pollution is limited to the distant horizon. Many deep-sky objects such as galaxies and nebulae reveal good detail when observed through a telescope.

Rural

rural light pollutionRural locations will give excellent views of the brighter regions of the Milky way especially directly above and away from the horizon where there can be some effects of sky-glow from local light pollution sources. The brightest deep sky objects reveal good detail and look fantastic through a telescope.

Semi-rural

semi-rural light pollutionDespite more localised light pollution from nearby sources semi-rural locations still offer fantastic views of the Milky Way if shielded from direct light. Deep sky objects can be readily observed although lose a bit of detail due to sky-glow.

Suburban

suburban light pollutionIn these areas the effects of light pollution really become noticeable with faint views of the Milky Way being limited to those who know where to look. Suburban locations however still offer the opportunity to observe objects through telescopes, deep sky objects are readily visible although it can be difficult to discern much detail. Brighter objects such as the moon and planets which are not as much affected by light pollution look fantastic through a telescope.

Urban

urban light pollutionUnfortunately urban areas are all too common! The Milky Way is not apparent at all and few stars can be seen when compared to a dark site. However, with visual aids such as binoculars or a telescope, some of the very brightest objects can be seen albeit with little if any detail, despite the high light pollution levels planets and the moon still look awesome through a scope!

Latest from the blog

Our most recent astronomical articles...