December 5, 2021

I, Science

The science magazine of Imperial College

This article is taken from the Winter 2011 issue of I, Science.

Jennifer Whyntie talks to astrobiologist Lewis Dartnell about what got him started, Conan the Bacterium, skywhales, and how he balances science outreach with his research.

Lewis Dartnell is a research fellow at UCL’s Institute of Origins, having done a PhD in astrobiology and the search for life on Mars. He is also a prolific figure in science outreach, writing for the Daily Telegraph, New Scientist, BBC Focus and the Sky At Night. He has just published his first book Life in the Universe: A Beginner’s Guide.

JW: How did you get into astrobiology – what attracted you to it?

LD: Erm … the fundamental answer is that I was just a big geek. I read lots of sci-fi as a kid and was always thinking about aliens and Starfleet. The science has matured. It’s treated as a real science now, as a meaningful area of research. There’s been some big breakthroughs that have opened people’s eyes to this in terms of finding extreme forms of life on Earth, called extremophiles, and discovering planets orbiting other stars in the galaxy – there’s clearly a lot of real estate in the galaxy now. So astrobiology has come in from the cold because we’ve made big discoveries that tell us about the possibilities of life beyond Earth.

You said that you’ve been looking at these creatures on Earth called ‘extremophiles’ – what’s the coolest organism you’ve examined so far?

I’ve directly been researching a bacterium called Deinococcus radiodurans, which is the most radiation-resistant organism on the planet. It’s sometimes referred to as “Conan the Bacterium” because it can survive a whole lot of different extremes – it’s a polyextremophile. It can survive being desiccated, and blasted with ultraviolet radiation, and zapped with ionising radiation like gamma rays. It’s an altogether superhero of survival. And it forms these cute little bright pink colonies on agar.

So are you currently limited by the fact that we haven’t yet managed to get many probes to other planets?

Well, our nearest planet, Mars, we have explored in the past with probes. One of the other places in the solar system that we think has got a good shot of hosting life is Europa – one of the icy moons of Jupiter. What we really want to do is get a dedicated mission to Europa. Hopefully, in the not too distant future i.e. in my career we’ll go to the next step, which is to land on its surface and try to drill through its ice into the ocean that we think is there – the alien ocean. But that’s going to be a very difficult thing to do. It’s going to be expensive, and it’s going to take time before we can get there.

“Alien ocean” is the best phrase I think I’ve heard you use so far! Going beyond the solar system, I’ve heard you talk about skywhales before. Can you tell me a little bit more about them?

One of the public outreach talks I do is called ‘What would an alien look like?’ It’s deliberately provocative in the title, but you can draw an awful lot of quite robust, firm conclusions about what alien life might look like. You can work from basic physical principles and engineering constraints. At the end of the day life is just evolving to solve a problem – it might find the same solution on different planets, as we found here. So the idea is that if you’ve got a more massive planet with a stronger gravity, paradoxically, it would actually be easier to fly, not more difficult, because although the weight would increase with the gravity, the density of the air around you would increase faster. So on a “super Earth” – an Earth-like rocky planet with more gravity, with more mass and a thicker atmosphere – you might find some very big things soaring in the clouds above your head, such as things the size of elephants, which would be skywhales. You mention that you discuss skywhales when you do outreach. You’ve done lots of science communication.

How do you find balancing doing your sci comm and your research?

Tricky. I mean, it’s a problem of time management. I think you’ve got to be careful because a lot of the sci comm can be more enjoyable on a short-term basis. But you need to keep up your science. If you don’t keep up your publication record, you don’t get your next post-doc, your next fellowship position. You need to be very good at juggling between them. Often I find myself working on a Saturday or a Sunday to catch up from work in the week when I do a talk in a school, or working in the evenings. But if it’s something you enjoy doing then it doesn’t feel like a chore.

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