LIGHT
POLLUTION
Light pollution – current light pollution in my area?
Light pollution, light smog, light pollution or light pollution – all these terms describe a problem that has become more relevant and heard in recent years: We are talking about the artificial brightening of the night sky. At first glance, this may not sound particularly dramatic.
But on closer inspection, it quickly becomes clear that light pollution can also quickly become a problem that can disturb more than just our view of the starry sky. Do you want to know whether you are currently affected by light pollution? Then take a look at the light pollution map now!
The light pollution map shows you the areas with high light pollution in different colors. We’ll explain what color means what.
How to interpret the light pollution map:
You can discover many different colors on the light pollution map. These colors give you a precise insight into where you can expect light pollution. The color scale can be interpreted as follows:
- The colors dark grey, light grey, dark blue and light blue indicate very low light pollution. You will discover these areas particularly over maritime areas or on the high seas.
- The colors green, yellow and orange indicate light to moderate light pollution.
- Red, violet and white indicate areas with strong to very strong light pollution. The probability of being able to see stars within this area is very low.
💡 What you need to know about light pollution!
Table of contents
Now that we have introduced you to the light pollution map, we would like to take a closer look at the topic of light pollution and answer the most important questions. You may also recognize one or two questions that you have already asked yourself about light pollution.
📍 Definition and origin of light pollution
What is light pollution? – Light pollution explained simply!
Before we take a closer look at the topic of light pollution and its consequences, we first need to understand what exactly light pollution is. What is light pollution simply explained? Light pollution, light pollution or light smog describes the artificial brightening of the night sky through the use of man-made light sources such as floodlights, lanterns or other sources of illumination.
How does light pollution occur?
Light pollution is caused by an artificial light source and the atmosphere. When the light is emitted and the light radiation reaches the atmosphere, this radiation is scattered there. The result is the large-scale illumination of the night sky above the light source(s). Large areas of light pollution occur particularly when there are many individual, strong light sources directed into the sky.
📍Effects of light pollution
Why is light pollution bad?
At first glance, pollution caused by artificial light does not sound particularly tragic. Only on closer inspection does it become clear why light pollution can become a real problem. The artificial light radiation in the sky makes it much more difficult or almost impossible to see the stars. For some of us who only occasionally look up at the night sky, this will certainly not be too much of a problem. But there is one professional group in particular whose work is affected by light pollution. But more on that in a moment.
Artificial light sources can have a negative impact on people at night. Excessive exposure to light, for example, prevents the production of the sleep hormone melatonin and makes it harder for us to sleep. But artificial light is also increasingly affecting the animal world: this has a particular impact on nocturnal birds and insects, whose ability to find their way around is disrupted by the light.
Who is particularly harmed by light pollution?
We are talking here about astronomers, whose observations and results make an important contribution to research into the universe and (astro)physics. Under the influence of light pollution, it is impossible for them to study space with telescopes or take useful images of space for further research. Luminous satellites in particular can interfere with long-exposure images of space or even render them completely unusable. For this reason, observatories or large reflector telescopes are increasingly located in remote places to reduce the incidence of light to a minimum.
📍Avoidance of light pollution
Examples of light pollution
The majority of sources of light pollution are located on the ground. Streetlights, building lighting, floodlights and industrial lighting are the main contributors to light smog.
Outside the earth’s surface, satellites, airplanes and other aircraft such as helicopters are the main sources of light emissions.
Are there light pollution laws?
With its impact on humans and nature, light pollution can certainly be counted as environmental pollution. For a long time, however, there were no laws regulating the emission of light. However, there are now laws in various countries that regulate light emissions more precisely.
How can I avoid light pollution?
We can all take action to reduce light pollution ourselves. When using light sources indoors and outdoors, we should always ask ourselves whether the light is really needed. We should also make sure that the light source is positioned and adjusted in such a way that it only illuminates the usable area. Last but not least, the light point height should always be set as low as possible.
📍Making light pollution tangible
How do you measure light pollution?
The strength of light pollution is measured using the unit “SQM”. Translated, this abbreviation means Sky Quality Meter. The unit indicates the degree of light pollution per arc second in the night sky. An arc second is an angular unit of measurement that corresponds to 1/3600 of a degree. The Bortle scale is also well suited for assessing light emissions.
The higher the Sky Quality Meter, the greater the light exposure. The opposite is true for the Bortle scale. The following table provides a good overview of how the SQM and the Bortle can be interpreted.
| SQM | Bortle | Description |
| 18.0 | 8 | City sky, hardly any stars visible |
| 18.3 | 7 | Suburban sky with tendency towards city sky, only very few stars visible |
| 18.8 | 6 | Bright suburban sky with brightened sky, Milky Way is not visible |
| 19.8 | 5 | Suburban sky with barely visible Milky Way |
| 20.9 | 4 | Night sky with tendency to suburban sky, clouds in the zenith glow |
| 21.4 | 3 | Rural night sky, bright clouds on the horizon due to light |
| 21.6 | 2 | Very dark night sky without noticeable light emissions |
| 21.85 | 1 | Completely dark night sky without the influence of light sources |
Where is light pollution at its lowest?
To answer this question precisely, take a look at the light pollution map. Look for gray, blue or green areas. Within these areas you can expect a minimum of light smog.