How Many Stars Can You See?

GLOBE at Night's 2010 results
Thousands of North Americans contributed night-sky observations to GLOBE at Night's 2010 campaign. To see a zoomable version of all the reports, download this file and display it using Google Earth.
GLOBE at Night
With half of the world's population now living in cities, many urban dwellers have never experienced the wonderment of pristinely dark skies — and maybe they never will. This loss, caused by light pollution, is a concern on many fronts besides as well as our ability to view the stars: safety, energy conservation, cost, health, and effects on wildlife.

Even though light pollution is a serious and growing global concern, it is one of the easiest environmental problems you can address on local levels. Participation in the international star-hunting campaign, GLOBE at Night, helps to address the light pollution issue locally as well as globally.

This year, organizers have planned two campaigns. During the first one, from February 21st through March 6th, you're invited to record the brightness of the night sky. The second campaign runs from March 22nd through April 4th in the Northern Hemisphere and from March 24th through April 6th in the Southern Hemisphere.

It's easy and fun to do. First, you match the appearance of the constellation Orion (first campaign) or Leo or Crux (second campaign) with simple star maps of progressively fainter stars. Then submit your measurements, including the date, time, and location of your comparison. After all the campaign's observations are submitted, we'll release a map of light-pollution levels worldwide. Over the past five years, volunteers from more than 100 nations have contributed 52,000 measurements — a third of which came from last year's campaign.

To learn the five easy steps to participate in the GLOBE at Night program, see the GLOBE at Night website. You can listen to last year's 10-minute audio podcast on light pollution and GLOBE at Night. Encourage your local astronomy club, school, or other organization to participate with this 45-minute-long PowerPoint presentation and accompanying audio track. You can also find GLOBE at Night on Facebook and Twitter.

GLOBE at Night web app
New for the 2011 campaigns is a downloadable web application for smart phones and tablets that makes entering your observation a snap.
GLOBE at Night
The big news this year is that children and adults can submit their measurements in real time if they have a smart phone or tablet. To do this, you'll need our custom web application. With smart phones and tablets, the location, date and time are put in automatically. (For those of you who'll submit your observations using a home computer, the campaign's reporting page has user-friendly tools to find latitude and longitude.)

There's even a special program for kids, called the Dark Skies Rangers, that helps them explore what light pollution is, how it affects wildlife, and how to prepare for participating in the GLOBE at Night campaign.

Monitoring our environment will allow us as citizen-scientists to identify and preserve the dark sky oases in cities and locate areas where light pollution is increasing. All it takes is a few minutes during the 2011 campaign to measure sky brightness and contribute those observations on-line. Help us exceed the 17,800 observations contributed last year. Your measurements will make a world of difference!


An education specialist at the National Optical Astronomy Observatory, Connie Walker directs the GLOBE at Night Campaign and the IYA2009 Dark Skies Awareness Cornerstone Project.