Skip to main content

Digital Trends may earn a commission when you buy through links on our site. Why trust us?

Help tackle light pollution by identifying photos of cities taken from the ISS

The Iberian Peninsula at night, showing Spain and Portugal. Madrid is the bright spot just above the center. NASA

Light pollution is an environmental issue that you might not think much about, but it can have serious consequences. From interfering with astronomical research to impacting both wildlife and human well-being, too much artificial light at night can cause a range of problems. To understand the scale of the problem, the European Space Agency (ESA) is promoting a program to catalog images of cities taken from space and is asking for the public’s help.

The Lost at Night project aims to quantify and map artificial light pollution caused by humans, especially around major cities. It uses high definition photographs of the Earth taken from the International Space Station (ISS). “The International Space Station is the best observation point humankind has for monitoring Earth at night,” Kevin Gaston, project leader of Lost at Night, explained to the ESA.

There are more than a million photos of the Earth taken from the ISS in the NASA Astronaut Photography of Earth archive, providing a potential treasure trove of data about light pollution.

However, there’s a problem. The majority of the photos in the archive are uncataloged, so they have no location information. Without labeling describing which location an image shows, it can’t be used for data analysis.

The Lost at Night project invites regular people to contribute to science by helping to catalog these images. Citizen scientists can look through the images and identify which cities they show, and they can perform this task better than machines can. “While computer algorithms have trouble distinguishing between stars, the moon, and cities, people are more reliable when it comes to recognizing patterns and analyzing complex images,” Alejandro Sánchez de Miguel, a research fellow at the University of Exeter, UK and the lead investigator of the project, said in to the ESA.

The website shows a number of options for which city could be shown in each image and shows maps as well as the night-time image. The system requires five people to agree on which city is shown to accept that labeling, in order to decrease errors. Then the images can automatically be cataloged by an A.I. and are available for researchers to analyze.

The project aims to identify a total of 90,000 images, which would be enough to train an A.I. to recognize cities itself. To contribute to the project and try your hand at identifying cities, head to the Lost at Night website.

Georgina Torbet
Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…
Light pollution is cutting off views of the night sky for many
A startling analysis from Globe at Night — a citizen science program run by NSF’s NOIRLab — concludes that stars are disappearing from human sight at an astonishing rate. The study finds that, to human eyes, artificial lighting has dulled the night sky more rapidly than indicated by satellite measurements. The study showcases the unique contributions that citizen scientists can make in essential fields of research. This graphic illustrates how the greater the amount of light pollution, and therefore skyglow, the fewer the stars that are visible. The numeric scale is similar to the one used by Globe at Night participants. 

If you have even a passing interest in astronomy, odds are good that you've considered the problem of light pollution. As there are more and more sources of bright light at night on Earth, it makes it harder and harder to see the stars in the sky. But recent analysis has pointed out that the problem could be worse than anticipated, as what is visible to the human eye is even less than satellite measurements have indicated.

According to the National Science Foundation's NOIRLab, around 30% of the global population and 80% of the U.S. population can no longer see our galaxy, the Milky Way. And the new research shows that the problem is getting worse.

Read more
Astronaut’s photo from ISS shows Earth in a different light
astronaut photo from iss shows earth in different light cupola don pettit

An American astronaut has shared a wonderfully unique image of Earth taken from the International Space Station (ISS).

Three-time space visitor Don Pettit, who currently has his feet on terra firma, posted the remarkable photo on his Twitter account on Monday.

Read more
ISS astronaut’s photos capture a ‘wonderful world’
An image of Earth captured from the International Space Station.

It may not be a perfect world, but if you look in the right places it’s certainly wonderful.

International Space Station (ISS) astronaut Samantha Cristoforetti, for one, definitely thinks so. Inspired by Louis Armstrong’s 1967 classic What a Wonderful World, the Italian space traveler recently posted four sublime Earth images alongside lyrics from the legendary track.

Read more