Using citizen science to hunt for new planets

When I was growing up, one of my childhood heroes was Clyde Tombaugh, the astronomer who discovered Pluto. Since then, we have demoted Pluto from its planetary status. But it still was a pretty cool thing to be someone who discovered a planet-like object. Today, you have this opportunity to find a new planet, and you don’t even need a telescope nor spend lonely cold nights at some mountaintop observatory. It is all thanks to an aging NASA spacecraft and how the Internet has transformed the role of public and private science research.

Let’s start in the beginning, seven years ago when the Kepler spacecraft was launched. Back then, it was designed to take pictures of a very small patch of space that had the most likely conditions to find planets orbiting far-away stars. (See above.) By closely scrutinizing this star field, the project managers hoped to find variations in the light emitted by stars that had planets passing in front of them. It is a time-tested method that Galileo used to discover Jupiter’s moons back in 1610. When you think about the great distances involved, it is pretty amazing that we have the technology to do this.

Since its launch, key parts of the spacecraft have failed but researchers have figured out how to keep it running using the Sun’s solar winds to keep the cameras properly aligned. As a result, Kepler has been collecting massive amounts of data and downloading the images faithfully over the years, and more than 1,000 Earth-class (or M class, from Star Trek) planets have already been identified. There are probably billions more out there. 

NASA has extended Kepler’s mission as long as it can, and part of that extension was to establish an archive of the Kepler data that anyone can examine. This effort, called Planethunters.org, is where the search for planets gets interesting. NASA and various other researchers, notably from Chicago’s Adler Planetarium and Yale University, have enlisted hundreds of thousands of volunteers from around the world to look for more planets. You don’t need a physics degree, you don’t need any sophisticated computer or run any Big Data algorithms. Instead, if you have a keen mind and eyesight to pore over the data and the motivation to try to spot a sequence that would indicate a potential planetary object.

What is fascinating to me is how this crowd-based effort has been complementary to what has already happened with the Kepler database. NASA admits that it needs help from humans. As they state online, “We think there will be planets which can only be found via the innate human ability for pattern recognition. At Planet Hunters we are enlisting the public’s help to inspect the Kepler [data] and find these planets missed by automated detection algorithms.”   

Think about that for a moment. We can harness the seemingly infinite computing power available in the cloud, but it isn’t enough. We still need carbon-based eyeballs to figure this stuff out.

Planet Hunters is just one of several projects that are hosted on Zooniverse.org, a site devoted to dozens of crowdsourced “citizen science” efforts that span the gamut of research. Think of what Amazon’s Mechanical Turk does by parcelling out pieces of data that humans classify and interpret. But instead of helping some corporation you are working together on a research project. And it isn’t just science research: there is a project to help transcribe notes from Shakespeare’s contemporaries, another one to explore WWI diaries from soldiers, and one to identify animals captured by webcams in Gorongosa National Park in Mozambique. Many of the most interesting discoveries from these projects have come from discussions between volunteers and researchers. That is another notable aspect: in the past, you needed at least a PhD or some kind of academic street cred to get involved with this level of research. Now anyone with a web browser can join in. Thousands have signed up.

Finally, the Zooniverse efforts are paying another unexpected benefit: participants are actually doing more than looking for the proverbial needle in the haystack. They are learning about science by doing the actual science research. It is taking something dry and academic and making it live and exciting. And the appeal isn’t just adults, but kids too: one blog post on the site showed how Czech nine year old kids got involved in one project. That to me is probably the best reason to praise the Zooniverse efforts.

So far, the Planet Hunters are actually finding planets: more than a dozen scientific papers have already been published, thanks to these volunteers around the world on the lookout. I wish I could have had this kind of access back when I was a kid, but I also have no doubt that Tombaugh would be among these searchers, had he lived to see this all happening.

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