Chris Lintott talks astronomy and citizen science

Fast becoming the face of astronomy after his success on The Sky at Night – Chris Lintott also pioneered the concept of citizen science in the field with Galaxy Zoo, which later became part of the Zooniverse - a collection of web-based  projects that use the efforts and abilities of volunteers to help reseachers deal with their 'data deluge'. But just how do you recruit the public to help with your research?

Firstly, what initially sparked your interest in astronomy? Looking at the night sky – the idea that we’re on a tiny planet in the middle of galactic nowhere, but that we can try and figure out what all this stuff above our heads is has always been inspiring.

What are your main research interests? On the astronomical side, I’m interested in how the Universe we see around us came to be. In particular, I’m interested in how galaxies form and evolve and what that can tell us about the larger history of the Universe. To do this we work with hundreds of thousands of volunteers from around the world, and so I’m also interested in studying how we can best make use of their time – that’s part of my research too.

What were you doing at Oxford University before Galaxy Zoo came to be? I arrived knowing a little bit about star formation and not a lot about galaxies – in particular, I’d been studying the chemistry of star formation. That sounds a little surprising, because we’re used to hearing about astrophysics not astrochemistry, but it turns out we can learn a lot from studying the molecules that form in the cold, dark places where stars are being born. A new telescope called ALMA was being built in Chile, and I thought that it might give us a chance to look at how stars might form in other galaxies, and so I came to Oxford to learn about galaxy formation and evolution.

Galaxy Zoo requires online volunteers to classify  images of galaxies by shape. Why was it so important to distinguish between “spiral” and “elliptical” galaxies? The shape of a galaxy tells us about its history; by classifying galaxies according to their shape we learn how they’ve interacted, when and how their stars have formed, and also about the forces that shape the Universe.

What happens to the data after it’s been classified? We have several people look at each galaxy, and so our first major task is to listen to all of those people and then make a decision about what the right answer is. That takes some time, but we can then release the data for scientists all over the world to use and so that we can attack our science questions.

What was people’s motivation for visiting the Zooniverse site, do you think? Rather wonderfully, we know from surveys of our volunteers that the major motivation is that people just want to help – to make a real contribution to research. That’s the magic of these projects: by sitting in front of a web browser and spending a few minutes you can see something that’s never been seen before and make an authentic contribution to science by doing so.

What are the main advantages of citizen science projects such as Galaxy Zoo? They allow us to cope with the sheer scale of modern datasets; we invented Galaxy Zoo because we had a million images of galaxies and not nearly enough people to sort through them ourselves. Another major advantage is that because human beings are incessantly curious, we can make serendipitous discoveries of the weird and the wonderful things hidden in the dataset.

Are there any downsides? I’m not sure it’s a downside, but it’s definitely true that not all projects are suitable for citizen science. There are those where computers are more than up to the job, for example – we wouldn’t want to waste people’s time by asking them to do something that could be perfectly adequately done by a machine.

You spent a year as the Director of Citizen Science at the Adler Planetarium in Chicago – what did you do there? Adler’s a fabulous place – one of the few places in the world where there are experts in science and in educating and communicating with the public working in the same place. Lots of our team are still based there, and I get back whenever I can.

There have been many academic papers published from the results of your citizen science projects - what are some of the most exciting discoveries? This is like being asked to pick my favourite child! I think the discoveries from Planet Hunters are particularly close to my heart, especially last year’s discovery of Planet Hunters 1b, the first planet found in a system with four stars. Imagine standing on the surface of a moon orbiting this Neptune sized world and seeing not one, but four suns hanging in the sky. It’s like something from science fiction.

I keep hearing about “green pea” galaxies – what are these? These are small dwarf galaxies that for reasons that are so far unclear have decided to convert all their gas into stars at once, making them the most efficient stellar factories in the local Universe. They were discovered by a group of Galaxy Zoo volunteers who called themselves the ‘Peas Corps’, and who did a lot of the work themselves. It was their efforts that really woke us up to the fact that volunteers could do much more than just click through and answer questions that we’d asked.

A Galaxy Zoo participant discovered Hanny’s Voorwep in 2007 – what exactly is this? It’s a galaxy-sized cloud of hot gas, hanging in space near a galaxy called IC2497. The mystery lies in understanding how it got hot – there are no stars in the cloud to heat it. We think it was ionized by a jet driven by accretion onto IC2497’s black hole, but the galaxy is quiescent today, making it one of the few places in the Universe to look if we want to study how galaxies switch from being actively accreting objects called quasars to quiet normal galaxies.

What advice would you give to one of our scientist readers looking to become involved in citizen science? Have a play with the projects on Zooniverse.org and then keep that in the back of your mind next time you’re struggling with the problem of processing a large dataset. It’s hard to force these things – it’s much better to wait for a problem where the help of hundreds of thousands of people is truly needed rather than make something up to satisfy a desire to engage in citizen science. Authenticity is key, but if you’ve got that then come and talk to us. Our code is increasingly open, and we like building projects to help others.

What are your future hopes for citizen science? I think the next big challenge is in dealing with live data – there are plenty of science cases where rapid assessment of data is needed, either to make decisions about follow up or because not all of the data can be stored for the long term. That means we need to be much more efficient in getting through data, paying attention to which task should be given to which people. That sort of development also opens up opportunities for feedback, and for learning which we’re excited to explore.

For more from Chris and Galaxy Zoo, check out our Citizen Science feature