Catalog of 300,000 Galaxies Produced in Mass Crowdsourcing Project

More than 83,000 volunteer citizen scientists have joined together to help produce a catalog containing data on an excess of 300,000 galaxies.

Named Galaxy Zoo 2, the project represents the second phase of a mass, public effort to categorize galaxies throughout the universe and is 10 times larger than any previous catalog of its kind.

According to the international group of researchers overseeing the effort, while computers are well equipped to automatically measure properties such as size and color, characteristics like shape and structure are better left up to human eyes.

Between February 2009 and April 2010, participants sifted through images gathered from the Sloan Digital Sky Survey to answer questions regarding each galaxy, including whether it has spirals or long extended features known as galactic bars.

Moreover, every image was classified an average of 40-45 times to order to ensure accuracy. In all, more than 16 million classifications were made through a total of 57 million computer clicks -- the equivalent of 30 years of full time work from one researcher.

"This catalog is the first time we've been able to gather this much information about a population of galaxies," said Kyle Willett, a physics and astronomy postdoctoral researcher in the University of Minnesota's College of Science and Engineering and the paper's lead author. "People all over the world are beginning to examine the data to gain a more detailed understanding of galaxy types."

When participants were asked why they chose to get involved, the most common answer was that they enjoyed feeling involved in science.

"With today's high-powered telescopes, we are gathering so many new images that astronomers just can't keep up with detailed classifications," said Lucy Fortson, a professor of physics and astronomy in the University of Minnesota's College of Science and Engineering and one of the co-authors of the research paper. "We could never have produced a data catalog like this without crowdsourcing help from the public."

Available online, the paper describing the project is available in the Monthly Notices of the Royal Astronomical Society.