Galaxy Zoo 2 Project Citizen Scientists
September 24, 2013

Galaxy Zoo 2 Enlists Citizen Scientists To Catalog The Universe

[ Watch the Video: Galaxy Zoo 2 Project Crowdsourcing Catalogue ]

Brett Smith for - Your Universe Online

With today’s modern telescopes collecting new data on the vast stretches of our universe at an unprecedented rate, astronomers are having a hard time keeping up. For help, an international group of researchers has turned to everyone’s favorite resource – the Internet.

By enlisting over 83,000 volunteer citizen scientists online, researchers at the Galaxy Zoo 2 project have made more than 16 million new galaxy classifications and gathered information on more than 300,000 galaxies.

The project is the second phase of a crowdsourcing campaign to classify galaxies in our universe. Project officials said computer algorithms are good for automatically calculating properties such as size and color of galaxies. However determining finer characteristics, such as a shape and structure, can only be done by the human eye.

The result of all this work is a catalog 10 times larger than any previous similar catalog and available online at A paper describing the work was published on Tuesday in the Monthly Notices of the Royal Astronomical Society.

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

Between February 2009 and April 2010, volunteers from around the globe examined images online that were taken from the Sloan Digital Sky Survey. Volunteers were asked if the galaxy they were looking at had spirals and, if so, to count the number of spiral arms present. They were also asked to determine if the galaxy had galactic bars, which are long extended regions containing a higher concentration of stars. Each image taken from the sky survey was classified an average of 40 to 45 times to increase accuracy. In all, the work performed by the volunteers represented about 57 million computer clicks.

When asked why they decided to volunteer their time, participants most frequently said it was because they enjoyed contributing to science. Project scientists estimated that the combined effort of the volunteers was equivalent to about 30 years of full-time work by one staffer.

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

Fortson compared the Galaxy Zoo 2 project to a census of the galaxies. The newly expanded catalog of known galaxies provides a snapshot of the various kinds of galaxies as they appear today. The next phase of the project will attempt to learn more about galaxies in the distant past. The two phases combined together will provide us with a greater understanding of how our own universe is changing, the researchers said.