Skip to content

The City Dark

Take Action

Investigate the Effects of Light Pollution

The City Dark examines the effects of artifical light and light pollution on the human relationship to the night sky. Discuss the impacts of light pollution in your own communities and ways to reduce it.

The Meaning of the Night Sky

  • Have you ever been inspired by a majestic night sky? Create a piece of artwork, video, poem, essay or song that expresses your experience. Invite others to do the same and share your work by creating an online gallery, convening a poetry slam or serving as curator for a show at a local library (or other public space).

  • Study the history of the constellations. What were the sources of images that were chosen and how did they reflect the societies that chose them? Which of the constellations are visible from the region where you live and how does what is visible change with the seasons? Once you are familiar with the constellations, try your hand at stargazing. Take a trip to a dark spot and see how many constellations you can spot. As part of your stargazing experience, invent and draw your own constellations so that others can spot them.

  • Neil deGrasse Tyson observes that "every civilization has a mythology about the night sky." Have each person in your group or class choose a civilization and research its sky mythology. Share and compare and contrast everyone's findings. What do you learn about commonalities and differences over time, place and culture?


  • Hold a career day. Invite astronomers, astrophotographers, aerospace engineers, astrophysicists and environmentally friendly lighting designers to help young people in your community learn about sky-related careers.

  • Make your facilities more energy-efficient. Learn about the California Energy Commission energy efficiency standards and its efficiency financing program for local government, hospitals, schools and colleges. Savings have proven to reduce annual utility costs by an average of 20 percent.

  • Get updates on the work of the scientists in Hawaii who are part of NASA's Near-Earth Asteroid Tracking program at Share your views with your elected representatives about continued funding for this NASA program.

  • Visit a planetarium. Note what you see there that you can't see in the night sky from your home. Think about what it might be like if, at some point in the future, the planetarium were the only place people could go to see the night sky. How might such a society differ from our own?

  • Discuss what is visible in the night sky where you live in a letter to a pen pal, a post on your Facebook page and/or a post on an astronomy bulletin board or chat room.


  • Consult with local nature centers, museums or conservation groups about threats to local wildlife from light pollution. Find ways to work together to mitigate the threat.

  • Listen to EarthSky's radio shorts on your local NPR radio station or online at Use EarthSky's programs as a model to create your own podcasts on light pollution and habitat.

  • Learn how to navigate using the stars. As background, investigate historical figures who used the stars to navigate, such as 15th- and 16th-century explorers and conductors on the Underground Railroad. Seek out folkloric discussion of navigation by stars, such as the folk song "Follow the Drinking Gourd." Then, find a class to learn navigation by the stars (sometimes available at local camping or nature centers), or visit one of the many resources available on the Internet, such as Once you gain some confidence, plan a night hike using the stars to navigate.

  • Host a stargazing party. Invite guests to bring their own telescopes or make supplies and instructions available so that guests can build their own telescopes.

  • Participate in the worldwide star survey Globe at Night, in which citizen-scientists count the stars visible from their towns and cities and add their tallies to a map of the earth's night sky quality. Visit to learn more.


  • Craft a public health policy that covers night-shift work. Share with your local and state health departments and work with them to recommend workplace regulations to the Occupational Safety and Health Administration and other regulatory agencies.

  • Work with local unions and employers to disseminate wellness strategies to night-shift workers and, where possible, to eliminate the need for night-shift work.

  • Urban Planning

    • Brainstorm a list of all the things that you think could be done in your community to reduce light pollution. Choose one or two items from the list and, together with local civic groups and clubs, create an action plan to implement them.

    • Reach out to lighting professionals through a local chapter of the Illuminating Engineering Society of North America (IES). Good lighting design is economical, energy-efficient and dark-sky friendly, in addition to being aesthetically pleasing. Consult with lighting professionals to educate your community on good lighting practices.

    • Learn how the U.S. Green Building Council's LEED program helps reduce light pollution and learn how architects can incorporate bird-safe design elements into new architecture for commercial and residential buildings at

    • Learn more about lighting design by examining your own environment. Ask yourself how lighting affects your perception of where you live. Think of a place in your surrounding area that you enjoy or do not enjoy. Consider how this space is lit.

    • Visit the American Bird Conservancy website and find out how you can take steps to make buildings in your community bird-friendly.

    • Calculate the lumens of various light fixtures in your home, business or community. Compare them to the lumens of alternative light sources, such as candles or other types of bulbs. Determine whether or not there are locations where you could decrease the lumens and still get the illumination you needed. Create a plan to act on your findings.

    • Learn about organizations like Engineers Without Borders ( and recent efforts to bring new light and power to small towns in the developing world.

    • Find out more about lighting design, a field whose professionals have expertise in the art and science of light and lighting.

Get informed about the issues in the film and lead a discussion in your community.

Discussion Guide

Discussion Guide

The City Dark is a feature documentary about light pollution and the disappearing night sky. After moving to light-polluted New York City from rural Maine, filmmaker Ian Cheney asks, “Do we need the dark?” The film develops out of his search for an answer to that question.

Exploring the threat of killer asteroids in Hawaii, tracking hatching turtles along the Florida coast and rescuing injured birds on Chicago streets, Cheney unravels the myriad implications of a globe glittering with lights — including increased breast cancer rates from exposure to light at night, and a generation of kids without a glimpse of the universe above.

Featuring stunning astrophotography and a cast of eclectic scientists, philosophers, historians and lighting designers, The City Dark is a story of light pollution and the disappearing stars. The film asks viewers to stop and ponder what light, darkness and the stars mean to us, spiritually, physically, intellectually, socially and economically.

Lesson Plan

Lesson Plan

In this lesson, students will study the nesting process of the endangered loggerhead turtle species and watch a video clip that illustrates how artificial lighting along nesting beaches disorients turtle hatchlings and hinders their ability to reach the ocean successfully. Students will then identify ways that humans can reduce the threat of such lighting to natural habitat.

Reading List

Delve Deeper

This multi-media resource list, compiled by Erica Bess, Susan Conlon and Martha Perry Liu of Princeton Public Library, provides a range of perspectives on the issues raised by the POV documentary The City Dark. Learn more about light pollution, astronomy, and urban planning.

Share This

Upcoming Films