Night lights and prosperity don't always go hand in hand

North Korea is famously dark compared to South Korea and China at night, and images like the one below are often used to demonstrate the consequences of its "unenlightened" policies.

Photo ISS043-E-247811 from the International Space Station ISS.
See more like this at Cities at Night.

I certainly wouldn't want to live in North Korea, but is it an absolute truth that bright lights indicate prosperity, and lack of bright lights poverty and backwardness? The border between Germany, Belgium, and The Netherlands would suggest otherwise:

The border of The Netherlands, Belgium, and Germany at night.
Image from an International Astronomical Union press release.

The area of Germany shown in the photo is part of the Ruhrgebiet, home to 8.5 million people and one of the most industrialized areas in Europe. Nevertheless, the comparison of Germany to Belgium and The Netherlands is nearly as visually striking as that between North and South Korea. This is at least partly due to German lighting policy: Germany rarely lights its Autobahns (highways), and cities and towns are conservatively lit, often intentionally not following the European (DIN) norms for street lighting.

Last year we published a paper that examined the differences in lighting between cities and towns in the USA and Germany. American towns of 10,000 emit on average three times more light per capita than German towns, and cities of 100,000 emit more than five times more light per capita.

Total light emission from cities in Germany and the USA compared to community population.
Figure 5 from "High-Resolution Imagery of Earth at Night: New Sources, Opportunities and Challenges".

Germany uses far less light than its neighbors and the USA. Despite this, it is a prosperous country that is highly visited by tourists. It has low crime rates (the burglary rate is only 1/3 of that in the brightly lit Netherlands and just over half that of Belgium) and low rates of death due to traffic (about 1/3 less per 1 billion vehicle kilometers than USA or Belgium).

So if bright lights aren't needed to attract tourists, reduce crime, or make driving safer, then why do so many cities have such bright lights? Now that's a $100 billion question.

Note: Thanks to Alejandro Sanchez de Miguel for sharing the two ISS images with me.

Update: If you liked this post and want to learn more, check out this blog's "view from your app" photo series, that often highlights how good lighting is about more than how bright lights are. Some other blog highlights are about what a single floodlight can do to a natural area, the promise and peril of LED lighting, and citizens push back on LED lighting.

Amazing new photos from the International Space Station

The astronauts on the International Space Station have recently taken some absolutely outstanding photos of cities at night. Let's start with my former home of Berlin:

Berlin, Germany

That's quite possibly the best photo of Berlin I've ever seen taken from the ISS!

The orbit of the ISS limits it to a band of latitude from about 52° S to 52°N. During a recent pass, the ISS reached its northern limit as it flew over North America. That allowed the astronauts to snap:

Tacoma, Washington, USA

Seattle, Washington, USA

Calgary, Alberta, Canada

Saskatoon, Saskatchewan, Canada

Winnipeg, Manitoba, Canada

I don't know which town this is, it's somewhere near the Atlantic coast.
If you know, let us know in the comments!

You can click on the names above to get access to the full resolution images.

These are some of the best nighttime photos I've ever seen taken from the ISS. Here's a zoom in of the Calgary photo to show just how amazing it is in full resolution. You can see the pattern on the ground from the individual lights, and the outline of buildings with illuminated surrounding areas:

Zoom in of the Calgary image

I accessed these images from the NASA website, who ask that if you use the image you provide this caption: "Image courtesy of the Earth Science and Remote Sensing Unit, NASA Johnson Space Center". However, I'm not sure which astronaut took the photos, so thanks may also be due to one of the other space agencies, and getting such imagery is only possible thanks to the European Space Agency's Nightpod instrument.

If you like looking at images of cities at night, you can help out our research by classifying images and identifying cities! We will use your classified images to understand the sources of light pollution, and to track changes in lighting technology to understand whether cities as a whole are really saving energy or not with the transition to LEDs.

I'd also like to thank Alejandro Sanchez de Miguel (leader of the cities at night project) for forwarding me the links to the Berlin and Calgary images.

UPDATE Dec 11, 2015: Alejandro passed on another amazing image of Frankfurt:

Frankfurt, Germany

Check out the amazing detail of Frankfurt Airport:

Zoom in of Frankfurt Airport

Have astronauts photographed your city at night?

Back in July, I blogged about a new portal that helps you find photos of cities at night, and three related citizen science projects. I have some astounding news about the project that I just needed to share!

Citizen scientists have completed the initial classification of over 130,000 images in the Dark Skies of ISS project. This projects sorts images taken at night on the international space station as to whether the picture contains either stars, cities, the astronauts, etc, and how sharp the image is. To avoid errors, each image was categorized by multiple participants, so that's probably over half a million classifications in less than half a year!

In the Lost at Night project, citizens apply their lay knowledge of local and international geography to identify which cities are in specific photographs. Every photo is again categorized multiple times, and this has resulted in the discovery of almost 2,500 images of cities that researchers like me didn't know existed. Images from cities like San Jose (shown below), and also from places less well known to Americans and Europeans, like Chennai, Inda, or Da Nang, Vietnam.

San Jose from the International Space Station.
High resolution image available from NASA.

The citiesatnight team has released a preliminary set of these photos within a Google interface so that you can easily check if your city has been photographed. Please bear in mind that this is not a final product. If you find a city that has been misclassified, they would appreciate it if you would report it to them. Believe it or not, that link contains only the cities classified by citizen scientists. The Atlas of images put together by professional scientists and enthusiasts is actually smaller in terms of number of images, and I explained the best way to use it in July.

Finally, the citiesatnight team has also released seven examples of images that were georeferenced by volunteers. In the Night Cities project, participants match locations on the image with locations on Google Maps, allowing the photos to be overlaid on top of a map. A total of 128 cities have already been georeferenced.

Manhattan at night, georeferenced by citizen scientists at citiesatnight.org

The citiesatnight project has been an astonishing citizen science success story. The project was put together almost entirely through volunteer time, as far as I know it hasn't received any government financing. The International Dark-Sky Association recognized its leader Alejandro Sanchez de Miguel with an award this fall. If you know of other ways in which the project could be recognized, please nominate it!

Note to journalists and researchers: citiesatnight asks that you cite this paper if you use the images in your work.

Full disclosure: Alejandro is a close friend of mine. I played a limited role in the project, mainly by providing some minor advice and lots of encouragement.