In Denmark, protecting the night sky is not just a scientific mission, it’s a growing community-driven initiative. Across the country, small local groups are preserving natural darkness and raising awareness about light pollution. Supporting and connecting many of these efforts is Aarhus University, which plays a unique role as both scientific advisor and communication hub. Through training, exchange and a strong belief in collaboration, the university helps turn local passion into long-term impact.
Photo: Katharina Fossgreen
Supporting passion with expertise
Across Denmark, numerous local dark sky groups take action to protect the night. These are not large organisations with formal strategies, but volunteers, neighbours and friends sharing a passion for the night sky. Aarhus University serves as a communication node, offering guidance, exchange networks and expert connections. When a group pursues DarkSky International designation, the university advises on standards and paperwork. Just as importantly, it emphasises that community events and dark sky activities can matter as much as certification.
One of the most effective ways the Aarhus university supports local action is by training dark sky guides. These courses teach locals basic astronomy, helping them highlight features in the night sky and inspire wonder in their guests. The guides then lead dark sky events and tours in their regions, passing on what they’ve learned to visitors, students and fellow enthusiasts. In many communities, these tours become small attractions, drawing new visitors and raising awareness.
Sustaining these efforts can be challenging. Many initiatives begin with enthusiasm but can lose momentum without support. That’s why the university facilitates connections between groups through regular exchanges and provides information and training to keep efforts going. This ongoing support helps initiatives evolve and remain active.
Photo: Science Museums
Understanding darkness through observation
Alongside training and community building, Aarhus University also brings science into the picture. It collaborates with dark sky groups across the country to carry out simple night sky observations.
Measuring darkness often involves unfamiliar units, numbers that mean little to non-scientists. Yet understanding and comparing levels of light pollution is key to protecting the night sky. That’s why the university focuses on making differences in darkness tangible and helping people experience them firsthand.
Using easy-to-handle telescopes and comparing what can be seen from various places, the university brings technical concepts down to eye level. It turns data into a shared experience: how bright are the stars here? How clear is the Milky Way there? Linking measurements with real observations helps people understand what darkness means and why it’s worth protecting.
In the town hall of Aarhus, city authorities are already actively working to reduce light pollution - taking measurements, developing lighting plans and installing new fixtures. So far, their engagement has mostly focused on the technical side. But a recent visit to the local observatory may have sparked a deeper shift in mindset. For many of these officials, it was the first time looking through a telescope and truly seeing the moon and stars up close. They were amazed by the experience and the beauty of the night sky. That experience helped them to better understand the meaning of their work and they could feel why it matters to protect the night. And sometimes, that kind of experience is all it takes to change a perspective and spark inspiration.
Aarhus University hopes to build on this momentum and continues reaching out to decision-makers. A first workshop with city staff has already taken place.
Photo: Lars Kruse/AU Photo
Explaining why dark sky protection matters
Understanding the meaning of natural darkness goes beyond measurements and stargazing. Artificial light at night affects birds’ migration patterns, confuses nocturnal animals, disrupts the growth cycles of plants and can even interfere with our own circadian rhythms. By making these ecological and health-related effects part of their outreach, Aarhus University helps people connect the dots between light pollution and its impact on wildlife and humans and why dark sky protection is needed.
This holistic perspective also plays a key role in the university’s educational mission. By showing how light pollution impacts both ecosystems and human well-being, alongside all other dark sky activities, the university creates powerful entry points for engaging young people. Many of its outreach activities are aimed at raising awareness among the next generation to spark interest in protecting natural darkness and studying the night sky. In doing so, Aarhus University not only supports the development of its own scientific community but also strengthens the work of local dark sky groups: a growing network of experts contributes valuable knowledge and momentum to the broader fight against light pollution.
Photo: Ruslan Merzlyakov
From local passion to national inspiration: Dark Sky Park Bulbjerg
The Dark Sky Park Bulbjerg is one example of how local initiatives can thrive even further with the support of training and networks. Two dedicated individuals – both volunteers – initiated the effort for dark sky protection on their own. They drew on personal knowledge, community ties and successful fundraising to increase dark sky protection activities and to submit the application for Dark Sky Park designation through DarkSky International.
The group had already submitted the application, built awareness and a foundation for activities before reaching out to the university. When they shared their plans for designation, Aarhus University offered to train the now expanded voluntary group of 12 persons, as dark sky guides. Through lectures and individual sessions, the volunteers learned to share the wonders of astronomy and lead night experiences for different audiences – from families and tourists to astronomy enthusiasts.
Today, the group’s activities range from stargazing and ecology-themed walks to lectures on light pollution or astronomy, often supported by the university. They are also organising historical lighting reenactment events in the dunes and along the shore, showing how local people formerly kept a lookout for ships in distress to save any castaways. These events benefit the region’s tourism, especially in the off-season, attracting visitors with calm, darkness and star-filled skies. Some have even moved to the area for that very reason.
The group continues to keep the park active and protected: organizing events, securing funding, reporting to DarkSky International and cooperating with the Danish Nature Agency. Regular exchanges with other Danish dark sky groups, facilitated by Aarhus University, further support their work. Through these exchanges the local groups from across Denmark share their knowledge, inspire new initiatives and help those groups who aim for DarkSky designation. Dark Sky Park Bulbjerg’s application now serves as inspiration for others and new joint projects are already in preparation, including the upcoming telescope-based darkness measurements in collaboration with the Aarhus University.
Photo: Poul Christensen
Building a support network to protect the night
In this way, Aarhus University’s work is not just about astronomy or even just about light pollution. It is about building a network of people who care. Scientists, amateur astronomers, citizens, guides, schools, local councils – each of them has a role to play. And the university sees itself as a place where these threads can be pulled together, a kind of communication node for all those trying to protect the night providing knowledge, advisory support and connections.
Collaboration and mutual support amplify the efforts of every individual, making them more impactful than they would be alone. By fostering these connections, Aarhus University plays a vital role in uniting passionate advocates and local communities, turning local initiatives into collective efforts for preserving the night sky. Through communication, education and shared experiences, these combined efforts have the power to raise awareness and create lasting change.
Author: Anna Vollmer
Use of AI: ChatGPT and Hemingway were used to improve the writing
Photo: Katharina Fossgreen
Photo: Poul Christensen
Photo: Ruslan Merzlyakov
Photo: Science Museums