"I see myself as a biologist or a biochemist, but... in the context of as a broader subject, it forces me to wrestle with physics, with cosmology, with chemistry, with geology, with earth sciences or planetary sciences, and that's a thrill. ...I think it's what most people are drawn into science in the first place for, because science, in its biggest sense, is what inspires people, and by the time that you've got to the level of doing a PhD, it's narrowed down so much that a lot of people are almost forced to lose their imagination, and their creativity as a scientist... I think astrobiology is a subject that puts all that back in, in heaps."