Astronomers at Yale University announced on September 22, 2011, the discovery of the first two potential exoplanets (planets outside our solar system, orbiting other stars) discovered by citizen scientists who are members of the Planet Hunters science project.
Since the online project launched in December 2010, some 40,000 web users from around the world have been helping professional astronomers analyze the light from 150,000 stars in the hope of discovering Earth-like planets orbiting around them. Users analyze scientific data collected by NASA’s Kepler mission, which has been searching for exoplanets since its launch in March 2009. Anyone may participate. There are planet hunters from many different countries.
In the video below, you can see how the Planet Hunters project works.
Yale astronomer and exoplanet expert Debra Fischer, who helped launch the Planet Hunters project, said:
This is the first time that the public has used data from a NASA space mission to detect possible planets orbiting other stars.
A paper about the discoveries, written by Fischer and a team of astronomers, will appear in the Monthly Notices of the Royal Astronomical Society.
The candidate planets orbit their host stars with periods ranging from 10 to 50 days – much shorter than the 365 days it takes the Earth to orbit the sun – and have radii that range in size from two-and-a-half to eight times Earth’s radius. Despite those differences, one of the two candidates could be a rocky Earth-like planet (as opposed to a gas giant like Jupiter), although neither is in the so-called habitable zone where liquid water, and therefore life as we know it, could exist.
Next, the Planet Hunters team – a collaboration between astronomers at Yale, the University of Oxford and the Adler Planetarium in Chicago – used the Keck Observatory in Hawaii to analyze the host stars. Fischer said:
I think there’s a 95 percent chance or greater that these are bona fide planets.
The Kepler team has already announced the discovery of 1,200 exoplanet candidates and will follow up with further analysis on the ones with greatest potential. Originally they had discarded the two found by Planet Hunters for various technical reasons that led them to believe they weren’t promising candidates.
Users found the two candidates in the first month after Planet Hunters launched. The Planet Hunters team sent the top 10 candidates found by the citizen scientists to the Kepler team, who analyzed the data and determined that two of the 10 met their criteria for being classified as planet candidates. The two candidates were flagged as potential planets by several dozen different Planet Hunters users, as the same data are analyzed by more than one user.
Scientists on the Kepler team obtained the data, but the public helped finance the project with their tax dollars. It’s only right that this data has been pushed back into the public domain, not just as scientifically digested results but in a form where the public can actively participate in the hunt. The space program is a national treasure – a monument to America’s curiosity about the universe. It is such an exciting time to be alive and to see these incredible discoveries being made.
Planet Hunters participants are now sifting through the next 90 days of Kepler data in the hope of adding to the count. Fischer said:
This is what we found after just a preliminary glance through the first round of Kepler data. There’s no doubt that, with each new round of data, there will be more discoveries to come.
Bottom line: Citizen scientists participating in the Planet Hunters online science project may have identified two exoplanets using data collected by NASA’s Kepler mission, according to Yale astronomer Debra Fischer. Fischer and a team of astronomers made the announcement September 22, 2011, and have written a paper describing the discoveries, to be published in the Monthly Notices of the Royal Astronomical Society.
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