Can You See the Stars?

A Sky-High Number of Measurements for the International Light Pollution Campaign, GLOBE at Night 2010!

GLOBE at Night is an annual citizen-science campaign that encourages people all over the world to record the brightness of their night sky. For two weeks every March, when the Moon is not out during the early evening and the constellation of Orion can be seen by everyone everywhere, children and adults match the appearance of Orion with 7 star maps of progressively fainter stars found on the website, www.globeatnight.org. They then submit their measurements (e.g., which star map they chose) on-line with their date, time and location.

This year the GLOBE at Night 2010 campaign (which took place March 3-16) set a record high of over 17,800 measurements from people in 86 countries. The dots (or points) on the resulting world map represent the contributed measurements of night sky brightness: the lighter colored the dot, the brighter the sky and the darker the dot, the darker the sky. The lightest colored dot (e.g., “Limiting Magnitude 1”) represents a night sky you might see from a very large city. Then, only a handful of stars are visible across the whole sky. The darkest dot (e.g., “Limiting Magnitude 7”) represents a night sky you would see from a national park where no city lights are visible. Then there would be so many stars across the sky (14,000!) that it would be hard to distinguish one constellation from another.

In the United States, 49 out of 50 states plus the District of Columbia contributed more than 10,900 measurements. The top three states were Arizona (over 1800), Michigan (over 1200) and West Virginia (over 1000). Puerto Rico had over 1,000 measurements; Poland over 800; Romania and Chile each over 600; the Czech Republic over 400; Argentina over 300; Hungary close to 300; Canada, the United Kingdom and South Korea just over 200; and China just under 200.

Thanks to everyone who participated! Through GLOBE at Night, students — alongside teachers, parents and community members — are amassing a data set from which they can explore the nature of light pollution locally and across the globe.

Read about GLOBE at Night 2010 News.