Citizen scientists turn planet hunters

Analysing astronomical data on their own computers using methods created at the University of Oxford helps volunteers understand the process of scientific discovery as they enjoy finding new planets; it also helps researchers turn numbers into knowledge.

Hundreds of thousands of ‘ordinary people’ around the world are helping astronomers detect new planets outside our own solar system, thanks to an extraordinary web-based tool developed by Dr Chris Lintott and his colleagues in the University of Oxford’s Department of Physics. Volunteer web-users are presented with graphs of data streamed back to Earth by NASA’s Kepler space observatory, which has been staring at the same patch of sky since 2009 and sending back thousands of images of stars.

The planet hunters are on the lookout for planets orbiting these stars, signified by a dip in image brightness when a planet passes between the star and the observatory detector. When they spot such a dip, they click on it to flag it up, simultaneously triggering the sending of that data to other online volunteers for verification. The planethunters.org website was set up in December 2010 and within its first six months of operation, around half a million volunteers had flagged up for closer inspection by NASA scientists about 70 ‘planet candidates’ that had been missed by automated computer detection techniques.

Planethunters follows on from the immensely successful Galaxy Zoo project launched by the Oxford team in 2007. This invited the public to classify millions of images of galaxies according to their shape, both as a way of processing huge volumes of data and because the human ability to recognise the unexpected in an image adds an important dimension to automated computer analysis.

Following the success of Galaxy Zoo and In response to requests from researchers in other areas, the Oxford astrophysicists built Zooniverse – a suite of software which can be tailored to other applications. Planethunters is one such application; others currently include analysing whalesound, studying ancient papyri, and examining Royal Navy ships’ logs to investigate the history of climate change.

Funded by: The Oxford Martin School, The Leverhulme Trust, and a Jim Gray Research Grant from Microsoft.