Discover New Worlds With Citizen Science: Planet Hunters

By Lily Bui | June 16, 2014 9:00 am

In Discover Magazine’s Jul/Aug print edition, “Exoplanet Naming” talks about naming conventions for newly discovered exoplanets. Planet Hunters is a citizen science project from Zooniverse where participants help astronomers identify new exoplanets.

What if I told you that you could help discover new worlds? You (literally) can – with citizen science!

Planet Hunters (official site) is a citizen science project from the Zooniverse that invites members of the public to collaborate with astronomers to identify new planets. Through data from the Kepler Spacecraft, participants look at and help classify light-curve data from stars within the Cygnus constellation.

Using citizen science data after only a couple months after the project launch in 2010, astronomers were able to identify two planet candidates: KIC 10905746 and KIC 6185331. (Phil Plait also wrote about the discovery of these two planet candidates in a Discover Magazine blog post.) Not only was the discovery of these candidates extremely exciting for the science community, it was also a testament to the efficacy of citizen science to help scientists work through large amounts of data.

When their first paper was published in 2011, over 40,000 users had contributed more than 3 million classifications of light-curves. The number of participants has grown significantly since then. (In fact, the overall Zooniverse community has reached over 1 million volunteers.)


How it works (and a brief astronomy lesson)

When planets pass in front of stars, the brightness of that star dips. This is called a transit. When the Kepler Telescope observes a star, this “dip” shows up in the light curves. While the patterns are not always easily recognized by computer algorithms, the human brain can fill in the gaps in identifying brightness dips. That’s where citizen scientists come in.

When you land on the project page, the site walks you through a brief tutorial about how to identify transits in light-curve graphs. You’ll get to test some for yourself before diving into the actual data.

Screen Shot 2014-06-03 at 2.22.30 PM

If you’d like to save your progress and see even more advanced data sets, you can create a login. Otherwise, you can participate as an unregistered user, which still counts toward the project’s overall progress.


What happens to the data afterward?

Participants can download the light curve data to analyze it independently or save the star to their Favorites on the website. The Planet Hunters research team found that citizen scientists correctly flagged about two-thirds of the transit events that were previously identified in an initial set of data.

After all transits are marked, participants also have the option to discuss any particular star on the Planet Hunters Talk site and connect with other citizen scientists.

According to the Planet Hunters paper in the Oxford Journal, the Talk site “is a critical component of the Planet Hunters project. Here, the science team interacts with the public, and experienced users…provide advice for new users.”


Why citizen science?

In short: there’s a whole lot of data and not enough scientists to go through it all efficiently.

Here’s the longer-winded version. On average, the Kepler Spacecraft takes brightness data every thirty minutes from over 150,000 stars (Jenkins et al. 2010). While the human brain is adept at detecting patterns, it’s less than practical for a single individual to review each of the light curves in every quarterly release of the Kepler data base (unless that individual also had an unlimited supply of caffeine and the ability to survive without sleep).

Crowdsourcing this task has allowed astronomers to distribute these tasks and involve even more people in their research. The project has become an educational opportunity for the public to increase their scientific literacy about exoplanet research as well as a more efficient means for astronomers to get better data.

On top of that, humans can be much better at recognizing things that computer algorithms like the transit planet search (TPS) algorithm, developed by the Kepler team, might trip over.

“Automated algorithms and citizen science are complementary techniques and both are important to make the best use of the Kepler data,” as expressed by the Planet Hunters research team in the Oxford Journal.

If nothing else, this project is yet another testament to the fact that citizen scientists (just like you) can make a difference. Now, go hunt for new worlds! They’re waiting to be discovered.


Images: Wikimedia, (screenshot)

Additional links:

Planet Hunters Tutorial:

Planet Hunters Talk page:


Fischer, Debra et al., 2011. “Planet Hunters: the first two planet candidates identified by the public using the Kepler public archive data.” Oxford Journal. 13 July 2011.

Jenkins J. M. et al., 2010, Proc. SPIE, 7740, 10

MORE ABOUT: astronomy, exoplanets
  • Uncle Al

    A carbon monoxide planet may be unstable to explosive decomposition, obtaining glassy carbon and carbon dioxide, “with an energy content [up to 8 kJ/g] rivaling or exceeding that of HMX,” [1]. The Earth’s gravitational binding energy (variable density method) is (-1.711×10^32 J)/(5.97219 × 10^27 grams) or -28.6 J/g [2]. A carbon monoxide planet might then be metastable to explosive disassembly by a factor of up to 278:1, (net chemical explosion energy)/(gravitational binding energy). boom

    [1] Nature Materials 4, 211 (2005), doi:10.1038/nmat1321

  • Brian Price

    I was wondering if instead of trying to find life on other planets, we could create our own planet, using a large nuclear powered electromagnetic,we could launch it into space and have it set in a orbit that’s just the right distance from the sun, near a large asteroid field, when it is turned on it would pull in metal asteroid fragments in, and begin to grow in size, as it grows in size, it would all so start to have a gravitational pull, to pull in asteroids that are not metallic, the Earths core is liquid Iron, a nuclear reactor melt down inside the new planet, could create this liquid metal core, after it no longer needs the giant electromagnetic to help it grow.


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Citizen Science Salon, brought to you by SciStarter, is where science enthusiasts can join forces with top researchers. We'll feature weekly collaborative, crowdsourced, and DIY research projects that relate to what you're reading about in Discover, so you can take science into your own hands. You can also find us on Facebook and Twitter.

About Lily Bui

Lily Bui is the Executive Editor of SciStarter and holds dual degrees in International Studies and Spanish from the University of California Irvine. She currently works in public media at the Public Radio Exchange (PRX) in Cambridge, MA. Previously, she helped produce the radio show Re:sound for the Third Coast International Audio Festival, out of WBEZ Chicago. In past lives, she has worked on Capitol Hill in Washington, D.C.; served in AmeriCorps in Montgomery County, Maryland; worked for a New York Times bestselling ghostwriter; and performed across the U.S. as a touring musician. This fall, she will be entering a masters program at MIT. In her spare time, she thinks of cheesy science puns.


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