Due to the increase in “light pollution” in Western Europe, many stars have become invisible at night. In the Dark Sanctuary, you’ll only notice what you missed as a result.
The sun disappeared behind the mountains around Lake Tekapo in New Zealand an hour ago. A large group of tourists ride in a pickup truck on their way to the Mount John lookout on top of the hill of the same name. You’ll immediately notice how dark it is here, with no street lights or oncoming traffic.
In the van, the driver asks not to use cell phones anymore. It takes the human eye more than 20 minutes to get used to complete darkness. Glancing at a bright screen or a headlight returns your eyes to their daytime mode. Only red light, the color with the lowest energy density, is allowed. The truck’s headlights go out before the tourists reach the top of the hill. The darkness outside is only disturbed by the faint blue trails of light from a few glowworms.
The observatory has a 360-degree panorama of Lake Tekapo and the surrounding areas. And, of course, about the starry sky. The conditions are ideal for this. The weather is cool and clear, and the humidity is low. The ribbon of the Milky Way stretches in a wide arc above our heads. From the Southern Hemisphere, the cluster looks out into our Milky Way, toward the galactic center. As a result, everything is visible that cannot be seen in the north.
Magellanic clouds
The band is remarkably bright and starry. The dark spots that you can discern in it are clouds of dust and gas. The constellations can be seen, as well as the Southern Cross and the star Alpha Centauri, which is our Sun’s closest neighbor at “only” four light years away. Also special are the Magellanic clouds. They are small galaxies outside our Milky Way. They literally look like little clouds among many stars.
Tekapo is located in the middle of the Aoraki Mackenzie International Dark Sky Reserve. It covers an area of 4,300 square kilometers in the heart of the Southern Alps, a mountain massif that cuts through the South Island of New Zealand. It is rough and sparsely populated. “To call us a Dark Sky Reserve, we had to show a database of every streetlight and other outdoor lighting,” says a guide at the observatory.
And we had to convincingly explain that the local population is involved and will make an effort not to produce unnecessary light. That was a success, and now there’s a lot more sharing with the locals. We regularly visit schools in the area, including outside the reserve, to tell children about it, so that they can be taught from an early age.
Blue and white light are not allowed
Educating and involving residents is of paramount importance, as living on a dark sky reserve clearly means that there are restrictions in terms of lighting. For example, outdoor lighting is permitted in principle only if absolutely necessary, eg for safety reasons or when wayfinding signs are in place. Exterior lights must point downward and be equipped with sensors or timers to prevent unnecessary use of the light. Blue and white light is out of the question, just like illuminated billboards, for example.
The result of all these efforts was a vast area in which darkness fell every night. But the real darkness. And that in a country that already had the darkest nights and therefore the most impressive starry sky in the world. New Zealanders are proud of it. “Now we are trying to become a Dark Sky Nation with the whole country, there is only one country around the world: the island nation of Niue in the Pacific Ocean. Maori culture shows us the way. They know better than anyone the significance of the dark night for people, nature and culture.”
The spectacle of the starry night sky has always aroused feelings of awe and wonder. Many ancient cultures saw their myths and ancestors reflected in them. The appearance of the sky also changes throughout the year. That made the starry sky a reliable beacon for keeping track of the seasons.
For Māori, for example, the appearance of Matariki—the striking star cluster we know as the Pleiades—at the end of June or the beginning of July signifies the beginning of the new year and the lengthening of days. The moon told them when it was time to sow, harvest, or set sail. But the stars were also indispensable to early Western explorers for locating themselves on the open sea. In this way, man looking at the stars has shaped his history to a large extent.
More and more light pollution
Thanks to our 24-hour economy, it’s not really dark at night anymore in the Netherlands, and certainly in the Randstad region. In many office buildings, fluorescent lighting remains on. The highways are flooded with light all night long, even when there are hardly any cars on them. In satellite images, the Netherlands, along with much of northwestern Europe, is clearly visible as a bright spot. Worldwide, most people live in places with light pollution. And the amount of artificial light is only increasing, on average, by 2% per year.
Increased light pollution causes us to lose the primal experience of the dark night sky. This is a big loss. But perhaps even more seriously, the constant presence of artificial light harms our mental and physical health. The biological clock is set to follow nature’s day and night rhythm. Morning light activates the system, while reducing light in the evening stimulates melatonin production, which makes people feel drowsy.
The constant availability of light is of course very beneficial. It also gives a sense of security. But the flip side is that we turn night into day. In a 2013 study on light pollution, the RIVM concluded that hundreds of thousands of people in the Netherlands experience mild discomfort or even disturbed sleep due to excessive artificial lighting in the evening and night.
Migratory birds are exhausted
Animals also suffer from addiction to artificial light. Research has already shown that songbirds that live in areas with lots of artificial light sleep shorter and start singing earlier in the morning. Lack of night sleep has a negative impact on their health. There are known examples of migratory birds getting lost over the sea or circling an illuminated rig, sometimes until they fall exhausted. Not everything is known yet about the effects of light pollution on the behavior of birds and other animals. However, good comparative research is difficult, because there are hardly any regions in the Netherlands without light pollution.
Another example is the swarms of insects around a bright lamp. Recent research (posted on bioRxiv, a preprint server for biological research) shows that these insects are not attracted to the light itself, as is often thought, but that the light disturbs their orientation. The researchers write that the insects determine what is above and below based on the intensity of the light. “Above” is where most of the light is always found: by the sun during the day, and the stars at night. Insects turn their backs to where the light is and so they continue to fly upright. According to the researchers, bright artificial light disrupts that mechanism. This causes the insects to flutter uncontrollably around the bulb.
Warm red light is much better
In general, light pollution is a real problem. But it could easily be otherwise, say the International Dark Sky Society, the international club behind Tekapo and many other dark spots around the world. Turn off or dim the lights that are not needed too often at night. Provide downward adjustable outdoor lighting, don’t make the artificial light too bright, and especially limit blue light, which has the highest energy density. Warm red light is much better. The development of LED light is considered promising according to the organization. The LED light is dimmable, economical, and easily adjustable for direction, color, and intensity.
Once back in the carriage, the group of tourists belatedly looked up at the stars. The sky here is just as impressive as it is at the observatory. Perhaps it is nicer here, because the high expectations of the tourist trip are gone. Here people “simply” look up and experience their cosmic environment in a way no longer possible in the Netherlands long ago: in silence, immersed in contemplation of place in the vast universe.
A haven for the stars
The International Dark Sky Association was founded to draw attention to the increase in light pollution and to protect and preserve the dark night for the future. It does this, among other things, by creating safe areas of darkness, somewhat in the same way that organizations are also trying to protect endangered species. In addition to the Dark Sky reserves, there are two more categories. Dark Sky Sanctuaries and Dark Sky Parks. Reserves are vast, often remote areas where, unlike reserves like Aoraki Mackenzie, public access is not a requirement. There are Dark Sky parks. The requirements for this title are slightly lower than those for the reserves, but it’s dark enough to see the starry sky well. There are two recognized Dark Sky parks in the Netherlands: De Boschplaat in Terschelling and Lauwersmeer in northern Groningen.
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