A group of researchers is creating a Google maps nocturnal version. The project is called “Cities at night” and aims at fighting light pollution.


Astronauts take pictures of our planet from the International Space Station every day. Some of them have already been published in different media, but almost half a million images remain unseen, stored in a huge database hold by NASA.


Left: Astronaut Samantha Cristoforetti taking pictures from the ISS cupola. Right: Madrid at Night as seen from the ISS. ISS030-E-82053. Images courtesy of the Earth Science and Remote Sensing Unit, NASA Johnson Space Center.


The project “Cities at night” aims at using all these images to create the first high-resolution night map of the world. The resolution of the map emerging from the project will be 10 times better than the one currently available, where cities look blurred when expanded. In addition to this overall enhancement, the new map will also include a brand new feature, which will enable users to detect the color of the light that our cities emit at night.


In the best map at night that exist cities blurry when expanded. Credit: Night-lights imagery by NASA’s Earth Observatory


The minds behind the project are physicists and astrophysicists from the Universidad Complutense de Madrid. “These images cannot be catalogued automatically, that’s why we need citizen collaboration”, says Alejandro Sánchez, responsible for the project together with Lucía García. “When we started in 2014, we used three different applications through which more than 17,000 volunteers have helped us classify, locate and georeference these images. Now, we are working to transform these applications into games, so collaborating will not only be useful for science, but also fun.”

The two scientists among a small group of volunteers have launched a crowdfunding campaign to seek funding for the design and the implementation of video games. In the final version of the game, the volunteers will see nocturnal images of cities and will have guess and identify which city is the picture portraying. By playing the game, users will help complete the set-up of the new version of the world map, which is partially already available on the project website.


“The result of this effort will not only be a beautiful map,” García says, “since this map will display data about sources of artificial light at night that scientists have been unable to study up until now.” The results of ‘Cities at night’ will support further research on light pollution, whose effects are still unknown by most. The European project STARS4ALL, coordinated by Universidad Politécnica de Madrid, raises awareness about additional effects, going several steps beyond the well-known inability to see the stars. Artificial light at night alters our biological clock, which has negative effects on human health and it’s also dangerous for plants and animals, threatening the general equilibrium of ecosystems. The new map that these scientist will create represent very important data for researchers that will be able to evaluate these effects better and help us find ways of improving our energy efficiency and reduce the resources we waste on excessive street lighting.


However, the topic still generates controversy when it comes to safety. “It is not about switching all the lights off, but using them only when appropriate, directing them to the ground and keeping adequate intensity levels,” says García. “A heavily illuminated road with a high contrast between some areas and others is actually less safe than another with uniform dimmed light.”


In the images of this new map, researchers will even be able to identify the lighting technology that is being used in each part of the city. This is especially important since the migration to LED technology usually involves a change of color and cold lights are installed instead of warm and what affects us negatively, since this kind of light is more energetic.

Mobile app concept. Images inside are courtesy of the Earth Science and Remote Sensing Unit, NASA Johnson Space Center.

More info:

Crowdfunding campaign: https://stars4all.mipise.com/en/citiesatnight

Cities at Night website: www.citiesatnight.org

STARS4ALL website: http://stars4all.eu

Low resolution night map: https://blue-marble.de/nightlights/2012

High resolution picture of Madrid: https://eol.jsc.nasa.gov/SearchPhotos/photo.pl?mission=ISS030&roll=E&frame=82053


Lucía García: lucia_garcia@ucm.es / 0034913944592

Alejandro Sánchez: alejasan@ucm.es  / 0034619358685