Observations of stellar visibility by citizen scientists accurately measure the brightness of the night sky

May 21, 2013

A team of researchers from Germany, Italy, and the USA have shown that observations of stellar visibility by citizen scientists accurately measure the brightness of the night sky. The researchers published their results Thursday in Nature Publishing Group's open access journal, Scientific Reports. The researchers hope that such data can eventually be used to track changes in artificial night sky brightness, also known as skyglow, worldwide.

The data the researchers analyzed came from the GLOBE at Night , which is coordinated by the U.S. National Optical Astronomy Observatory. Participants are asked to match the sky that they see with a series of star charts, that differ in how many stars are visible, and then report these observations online or with their smartphone. The researchers compared the participant's responses with nighttime satellite data and a worldwide simulation of skyglow, and showed that on average the results are very strongly related to the lighting in an area.

"Like other citizen science experiments, we find that the data is noisy but that aggregated data is accurate" said Christopher Kyba, physicist from Freie Universit├Ąt Berlin and the lead author of the study. "The individual observations have a standard deviation of almost a factor of 3 in sky luminance, but we found that these errors tend to cancel each other out, leading to highly stable measurements when we combine the data."

The researchers say that ground based observations of skyglow are important, because satellites that observe Earth at night measure the light that is radiating into the sky, not the brightness that is experienced by people and other organisms on the ground. Another drawback of the current satellites, according to the researchers, is that they aren't sensitive to blue light, so that areas lit by white appear darker then they really are.

"The goal of GLOBE at NIGHT is to have produce a long-term time series of observations." said Constance Walker, study author and Astronomer at the U.S. National Optical Astronomy Observatory. "Cameras and satellite sensors change all the time as technology develops, but time series based on the eye should be stable for centuries."

The researches hope to use future data from GLOBE at Night to estimate worldwide and regional trends in artificial . "We did the easy part, which is showing that there is a strong correlation between the stellar visibility reported and the amount of artificial light" said Kyba. "The challenge in determining trends will be to properly weight the data, particularly in areas with few or no observations."

Explore further: Sandblasting winds shift Mars' landscape

add to favorites email to friend print save as pdf

Related Stories

Red is the new Black

Aug 02, 2012

(Phys.org) -- The colour of night-time skyglow may be about to undergo a radical change worldwide, according to scientists of the Freie Universität Berlin and the Leibniz Institute of Freshwater Ecology ...

Clouds amplify ecological light pollution

Mar 02, 2011

The brightness of the nightly sky glow over major cities has been shown to depend strongly on cloud cover. In natural environments, clouds make the night sky darker by blocking the light of the stars but around urban centers, ...

Star Count Goes Global

Oct 15, 2008

Schoolchildren, families and citizen scientists around the world will gaze skyward after dark from Oct. 20 to Nov.3, 2008, looking for specific constellations and then sharing their observations through the ...

Italian all-sky imager tracks auroral red arcs over Europe

Mar 30, 2013

During geomagnetic storms, stable auroral red (SAR) arcs reach down from polar latitudes, their faint glow stretching equatorward of the traditional auroral oval. Invisible to the naked eye, SAR arcs are an upper atmospheric ...

Recommended for you

Video: Alleged meteor caught on Russian dash cam (again)

55 minutes ago

Thanks to the ubiquity of dashboard-mounted video cameras in Russia yet another bright object has been spotted lighting up the sky over Siberia, this time a "meteor-like object" seen on the evening of Saturday, Sept. 27.

Student to live in simulated space habitat

4 hours ago

A Purdue University industrial engineering doctoral student is among six "crew members" spending the next eight months in a domed habitat on a volcanic landscape mimicking life on a Martian outpost.

The wake-up call that sent hearts racing

7 hours ago

"But as the minutes ticked by, the relaxed attitude of many of us began to dissolve into apprehension. Our levels of adrenaline and worry began to rise."

US-India to collaborate on Mars exploration

16 hours ago

The United States and India, fresh from sending their own respective spacecraft into Mars' orbit earlier this month, on Tuesday agreed to cooperate on future exploration of the Red Planet.

User comments : 0