Meet The Hobbyists Hunting For The Solar System’s Hidden Planet

In searching for the hypothesized Planet Nine, tens of thousands of volunteers are helping NASA where computers can't

Illustration: Tara Jacoby
Apr 04, 2017 at 4:43 PM ET

One winter’s night 64 years ago, in the northern England city of Sheffield, an eight-year-old boy saw what he thought was a brilliant star fall out of the sky. “It’s not a star,” said his older brother. “It’s a meteor.” When Christmas came a few days later, the older brother passed along the unwanted present of a chemistry set.

“I started on the long road of science that day,” said Graham Dungworth, now 72 and living outside of London. Though the gift inspired Dungworth’s degree in chemistry and career in the petroleum industry, it was that earlier brush with the wider cosmos that guided his post-retirement pursuits.

Dungworth is one of the nearly 33,000 volunteers in the project Backyard Worlds: Planet Nine, which asks amateur astronomers to comb through about 200,000 images from NASA’s Wide-field Infrared Survey Explorer mission. WISE photographed the entire celestial sky between 2010 and 2011, taking some 2.7 million images. In these images could be previously unknown objects on our cosmic doorstep, even entirely new planets, that were just too faint or subtle to be noticed before now. The problem is there’s far too much data for scientists or even computers to analyze, which is why they turn to enthusiastic volunteers — a practice known as citizen science.

For about a decade, Dungworth has been one of those volunteers, participating in the projects posted on the platforms Galaxy Zoo and its extension, Zooniverse, where he returns to youthful interests like astronomy and cosmology, he told Vocativ via direct message on Zooniverse. The original Galaxy Zoo asked amateur astronomers to sift through huge collections of images to help better understand cosmic topics like merging galaxies and supernova explosions. Zooniverse has a more diverse mission, mixing astronomy in with other crowdsourced efforts like digitizing old weather records, monitoring wildebeest migration, and searching for exotic subatomic particles in data from the Large Hadron Collider.

While Backyard Worlds may be a hobby for most of its users, it’s all in service of serious scientific inquiry, with NASA actually helping to fund the current project through its Science Innovation Fund. The professional team leading Backyard Worlds hope to discover brown dwarfs — massive objects too small to ignite as stars but too big to just be planets — in the space between our solar system and the nearest stars. But the real prize is Planet Nine, a mysterious world hypothesized in the last few years to explain certain irregularities in the orbits of objects in the Kuiper Belt beyond Neptune. If it exists, Planet Nine is roughly the size of Neptune but orbits the sun at 20 times that world’s distance.

“Since Mike Brown and Konstantin Batygin announced evidence for the existence of a distant ninth planet in the solar system, astronomers have been furiously analyzing and collecting data in hopes of being the first to spot it,” wrote NASA astrophysicist and project creator Marc Kuchner on the project’s official blog. “A lot of the excitement is driven by the fact that planet nine may already have been detected in existing data sets. Astronomers love the idea of sifting through a huge pile of data to make that one epic discovery, and planet nine is the ultimate ‘needle in a haystack’ adventure.”

The method the citizen scientists employ in Backyard Worlds isn’t so different from how astronomer Clyde Tombaugh discovered the original ninth planet, which was, of course, Pluto. The then 24-year-old spent thousands of hours staring at photographs of the night sky to spot whether any apparent stars moved from one image to the next. On February 18, 1930, Tombaugh saw an object move. It wasn’t a star, nor was it a meteor. It was a planet — well, for the next 76 years at least, until Pluto got demoted to dwarf planet.

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Tombaugh estimated it took 7,000 hours of searching to find Pluto, which would work out to about 13 minutes of work for each of the 33,000 Backyard Worlds volunteers. Of course, Planet Nine hasn’t given up its secrets quite that quickly, assuming it is indeed out there, but that basic math speaks to how powerful crowdsourcing is for tasks like this.

Inn an age of artificial intelligence and automation, what’s perhaps most interesting is that the human eye remains astronomy’s best tool for this job. Computer algorithms can’t offer much help, as they struggle to distinguish between the tiny, natural juddering of distant stars in the images from the more substantial and significant movement of an object in our solar system’s immediate neighborhood.

Dungworth isn’t the only Backyard Worlds participant who is wetting a lifelong passion for astronomy. Zooniverse user jrchem recently retired from a 40-year career in chemistry and joined after seeing a note on the project on the NASA website. Fellow user mitch is semi-retired and first got involved in Galaxy Zoo a decade ago after hearing an interview on local radio. “I have always had a passing interest in the universe, so thought I’d have a look and then got hooked,” mitch said in a message.

While there’s a chance, however small, that one of these users could join Tombaugh as the discover of a brand new planet, this isn’t the all-consuming task it was 87 years ago. Dungworth, for instance, spends his days gardening, but said he had a little time to talk to Vocativ. “I have a spare half hour before the mist clears and then it is off to the allotment with much to do preparing the ground for planting,” he said.

There’s no guarantee anyone on the Backyard Worlds will actually find Planet Nine. “There’s a perhaps slim chance we will find it, 50,000 to one against assuming it’s in a decent image,” Dungworth said, though he was more optimistic that they would find brown dwarfs, those failed stars beyond the solar system.

Indeed, his efforts and those of his 33,000 colleagues are already paying off. Less than a month after its launch in February, project leader Kuchner announced that the science team had already identified four promising brown dwarf candidates from the submitted observations. A similar effort led by the Australian National University at the end of March turned up four candidates that could be Planet Nine or some other previously undiscovered object. It will take the professional astronomers months to review all the data the users submit, and the odds still remain long, but that’s the thing about hundreds of thousands of long shots: Take them all together and the chances suddenly look a whole lot better.