From the comfort of home, Web users may have found new planets

Planet Hunters analyzed real scientific data collected by NASA’s Kepler mission.
By | Published: September 23, 2011 | Last updated on May 18, 2023
Since the online citizen science project Planet Hunters launched last December, 40,000 Web users from around the world have been helping professional astronomers analyze the light from 150,000 stars in the hopes of discovering earthlike planets orbiting around them.

Users analyze real scientific data collected by NASA’s Kepler mission, which has been searching for planets beyond our own solar system — called exoplanets — since its launch in March 2009.

Now, astronomers at Yale University in New Haven, Connecticut, have announced the discovery of the first two potential exoplanets discovered by Planet Hunters users in a new study.

“This is the first time that the public has used data from a NASA space mission to detect possible planets orbiting other stars,” said Debra Fischer from Yale, who helped launch the Planet Hunters project.

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 2.5 to 8 times Earth’s radius. Despite those differences, the candidates could be rocky, earthlike planets (as opposed to giant gas planets like Jupiter), although they aren’t 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 in the United Kingdom and the Adler Planetarium in Chicago, Illinois — used the Keck Observatory in Hawaii to analyze the host stars. “I think there’s a 95 percent chance or greater that these are bona fide planets,” Fischer said.

The Kepler team has already announced the discovery of 1,200 exoplanet candidates and will follow up on the highest potential ones with further analysis, but they had discarded the two found by Planet Hunters users for various technical reasons that led them to believe they weren’t promising candidates.

“These … candidates might have gone undetected without Planet Hunters and its citizen scientists,” said Meg Schwamb from Yale. “Obviously, Planet Hunters doesn’t replace the analysis being done by the Kepler team. But it has proven itself to be a valuable tool in the search for other worlds.”

Users found the two candidates in the first month of Planet Hunters operations using data the Kepler mission made publicly available. 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. Several dozen Planet Hunters users flagged two candidates as potential planets, 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,” Fischer said.
“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 users are now sifting through the next 90 days of Kepler data in the hopes of adding to the count. “This is what we found after just a preliminary glance through the first round of Kepler data,” Fischer said. “There’s no doubt that, with each new round of data, there will be more discoveries to come.”

Planet-hunters
“Planet Hunters” from around the globe have used real NASA data to identify two potential planets orbiting stars beyond our solar system. Credit Michael Marsland
Since the online citizen science project Planet Hunters launched last December, 40,000 Web users from around the world have been helping professional astronomers analyze the light from 150,000 stars in the hopes of discovering earthlike planets orbiting around them.

Users analyze real scientific data collected by NASA’s Kepler mission, which has been searching for planets beyond our own solar system — called exoplanets — since its launch in March 2009.

Now, astronomers at Yale University in New Haven, Connecticut, have announced the discovery of the first two potential exoplanets discovered by Planet Hunters users in a new study.

“This is the first time that the public has used data from a NASA space mission to detect possible planets orbiting other stars,” said Debra Fischer from Yale, who helped launch the Planet Hunters project.

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 2.5 to 8 times Earth’s radius. Despite those differences, the candidates could be rocky, earthlike planets (as opposed to giant gas planets like Jupiter), although they aren’t 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 in the United Kingdom and the Adler Planetarium in Chicago, Illinois — used the Keck Observatory in Hawaii to analyze the host stars. “I think there’s a 95 percent chance or greater that these are bona fide planets,” Fischer said.

The Kepler team has already announced the discovery of 1,200 exoplanet candidates and will follow up on the highest potential ones with further analysis, but they had discarded the two found by Planet Hunters users for various technical reasons that led them to believe they weren’t promising candidates.

“These … candidates might have gone undetected without Planet Hunters and its citizen scientists,” said Meg Schwamb from Yale. “Obviously, Planet Hunters doesn’t replace the analysis being done by the Kepler team. But it has proven itself to be a valuable tool in the search for other worlds.”

Users found the two candidates in the first month of Planet Hunters operations using data the Kepler mission made publicly available. 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. Several dozen Planet Hunters users flagged two candidates as potential planets, 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,” Fischer said.
“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 users are now sifting through the next 90 days of Kepler data in the hopes of adding to the count. “This is what we found after just a preliminary glance through the first round of Kepler data,” Fischer said. “There’s no doubt that, with each new round of data, there will be more discoveries to come.”