Citizen Astronomers Discover Planets

Natalie Villa | natalie.villa@yale.edu April 3, 2011

Photo courtesy of Haven Giguere, Yale University.

Thanks to PlanetHunters.org, a new website that releases NASA data into the hands of the public, anyone, Ph.D. or no Ph.D., can make a sci¬ntific discovery. Astronomers are currently looking for evidence of Earth-like planets (“exoplanets”) outside of our solar system, but they need help, as the data consist of images of about 150,000 stars. It would be impossible for experts to search through this mountain of data by themselves, so they are relying on the assistance of citizen scientists. This project was co-founded by a number of Yale researchers, including Dr. Kevin Schawinski, a post-doctoral researcher in the Department of Astronomy.

The data come from the Kepler telescope, launched in March 2009. A single image shows the brightness of a star over a thirty-day cycle as a composite called a light curve. Sudden drops in brightness indicate that the star may have a planet orbiting it; when a planet passes in front of the star, it blocks some of the star’s light from reaching the telescope. Such an activity produces a characteristic effect on the light curve.

Computers are simply not as good at detecting these patterns as the human brain. “Human beings are actually really great at spotting patterns,” says Schawinski. “You can tap into something called ‘the wisdom of crowds effect,’ meaning that in many cases, taking the consensus of the group is much more accurate than asking a single expert.” Civilians have already identified several potential planets through the website, in the process, becoming scientists with just a pair of eyes and the click of a mouse.