The ALANIS Project Fights Light Pollution

Light pollution—excessive or improperly directed artificial lighting that escapes into areas where it is not needed—has become an unwelcome companion of modern life in recent decades. It affects the natural rhythms of nature, threatens biodiversity, complicates astronomical observations, and is increasingly linked by scientists to impacts on human health. Research shows that excessive light at night disrupts circadian rhythms—the internal biological clocks that regulate sleep, hormone production, and immunity—in humans as well as in animals and plants.

Petr Baxant, FEEC BUT. | Author: Václav Koníček

This challenge is being addressed by a project led by Petr Baxant from the Department of Electrical Power Engineering (FEEC, Brno University of Technology). The project focuses on the development and commercialization of two key tools: the web application ALANIS (Artificial Light At Night Information System) and a portable measuring device called ALANISATOR.

ALANIS serves as an advanced platform for collecting, analyzing, and visualizing data on light pollution. It integrates geographic data (GIS—systems for working with maps and spatial information), meteorological conditions, information about the Moon’s phase, and pollution maps from databases such as Light Pollution Map or the Light Pollution Atlas 2022. It enables users—from scientists to municipalities and companies—to track trends, identify sources of light pollution, and propose mitigation measures. The platform will gradually be expanded with analytical tools for evaluating biologically active radiation.

The ALANISATOR is a portable device for precise measurement of lighting conditions directly in the field. Unlike commonly available instruments, it can also capture melanopic radiation—the component of light that most strongly affects biological processes in living organisms, including the human sleep cycle. This ability to distinguish biologically harmful light from other radiation is one of the project’s key innovations.

“Light pollution is a problem that has long remained on the margins of attention, yet its impacts on human health and ecosystems are well documented. We want to provide a tool that allows this data to be systematically collected, shared, and used—whether for scientific purposes or for decision-making by cities and municipalities regarding public lighting,” says Petr Baxant, the project’s principal investigator.

He recently introduced his research to the broader public in the Experiment magazine on Radiožurnál. Among other things, he described measurements of Christmas lighting at Moravské Square in Brno and explained how excessive artificial light affects trees. Strong nighttime lighting disrupts their natural evaluation of day length. As a result, trees shed their leaves later, sap in branches remains active longer, and when frost arrives, it can freeze and damage tissues. Consequently, branches may dry out in the spring.

Over time, ALANIS could serve as a reference tool for systematic monitoring of light pollution—similar to networks of monitoring stations that track air or water quality. The project builds on previous research supported by the Czech Ministry of the Environment and collaborates with the Czech Technical University in Prague and the Czech Metrology Institute. The application will be useful for national park administrations and cities, operators of public lighting systems, as well as international environmental organizations. The project runs until the end of 2027, and its results could change the way we think about nighttime lighting.

You can meet Petr Baxant and learn about his research at the Earth Day 2026 event in Brno at Kraví hora on Saturday, April 18, where he will present the impact of light on our lives to the general public. Additionally, on Earth Day itself, April 22, the BUT Sustainability Office, together with Petr Baxant, is organizing a nighttime excursion titled “Turn Off the Lights and You’ll See.” It will begin at FEEC with a short visit to the lighting laboratory. Participants will then move to the Medlánky hills, where a practical demonstration of light pollution measurement will take place, accompanied by a small experiment. More information about this event can be found on the BUT Sustainability Office website.