Celebrate the stars! Created in 2003 by high-school student Jennifer Barlow, IDSW has grown to become a worldwide event and a key component of Global Astronomy Month. The goals of IDSW are to appreciate the beauty of the night sky and to raise awareness of how poor-quality lighting creates light pollution.

Light pollution is a growing problem. Not only does it have detrimental effects on our views of the night sky, but it also disrupts the natural environment, wastes energy, and has the potential to cause health problems.

Here are some ways that you can spread the word about IDSW during April 14-20 — and all year long:

• Check around your home. Make sure your outdoor-lighting fixtures are well shielded — or at least angled down — to minimize “light trespass” beyond your property. Do you have security lights that stay on all night? Consider adding a motion-detector, which can pay for itself in energy savings in just a few months. You’ll find lots of great suggestions in “Good Neighbor Outdoor Lighting” and you can perform your own outdoor lighting audit.
• Talk to your neighbors. Explain that bright, glaring lights are actually counterproductive to good nighttime vision. Glare diminishes your ability to see well at night, because the pupils of your eyes constrict in response to the glare — even though everything else around you is dark. Show them this handout.
• Ask your local library if you can put up an IDA poster showing good and bad lights. Include a photo of the Earth at night, and take some pictures around town that show examples of good and bad lighting.
• Attend or throw a star party! International Dark-Sky Week is a great opportunity to dust off the old telescope in your attic and use it share in the wonder of the universe with your family, friends, and neighbors. Visit the Night Sky Network to find a calendar of star parties or to find an astronomy club in your area.  Click here to find out what’s up in the sky. This activity book is full of great activities for budding stargazers of all ages!
• Photograph the sky and enter it in the 2012 International Earth and Sky Photo Contest on Dark Skies Importance or photograph some constellations and submit the pictures to the Dark Skies Photo Project to measure light pollution.
  
• Look for many more IDSW Events at the bottom of this page.
  

For more information, here are some great resources to learn about outdoor lighting and light pollution:

Global Astronomy Month, your gateway to a month-long celebration of the cosmos.

GLOBE at Night, a citizen-science program to measure light pollution from your own back yard 11-20 April, 2012.

Where to Buy lighting fixtures that are dark-sky friendly

IDA Practical Guides and brochures that explain light pollution’s negative effects.

2012 International Dark Sky Week Events

April 14 - 20 Night Sky Network Events (over three dozen listed in this link!).

April 13

8:00 p.m. - Stargazing at Trantia Farm, Homer Glen, IL - an International Dark Sky Community

April 14

10:00 a.m. - Dark Skies, an International Perspective. Screening of Korean Documentary Film For Those Denied the Night Sky. Introduced by Scott Kardel, of the International Dark-Sky Association

2:30 p.m. - Screening of The City Dark in Borrego Springs, CA - an International Dark Sky Community

6:00 p.m. Dark Sky Festival at Harmony, FL

7:00 p.m. Star Party at Catalina State Park Tucson, AZ

7:00 p.m. Great Basin National Park Spring Star Party, NV

7:00 p.m. Screening of The City Dark at John C. Wells Planetarium, Harrisonburg, VA

8:00 p.m. - Stargazing in Borrego Springs, CA - an International Dark Sky Community

April 15 

Texas Star Party (runs until April 22)

April 17

1:00 p.m. - Workshop on Measuring Light Pollution Hungarian Academy of Sciences Building at Pécs

April 18

8:00 p.m. Screening of The City Dark at Boise State University, Boise, ID

April 19

7:30 p.m. Lecture on exoplanets and the Mont-Megantic International Dark Sky Reserve followed by stargazing at McGill University Montreal, Canada.

April 20

9:00 a.m. Model Lighting Ordinance Workshop in San Diego, CA. Free, but registration required.

6:00 p.m. Lights Out over Huntsville screening of The City Dark at the U.S. Space and Rocket Center in Huntsville, AL

7:00 p.m. Star Watching Walks in Zselic International Dark Sky Park, Hungary (also April 21 at 6:15 p.m. in Hortobágy International Dark Sky Park, Hungary)

7:00 p.m. Screening of The City Dark (registration required) in Geauga Park's Observatory Park - an International Dark Sky Park located in Ohio

9:00 p.m. Screening of The City Dark at the Capitol Theater in Olympia, WA