[Astronomy] Why do people study exoplanets?

Something that we've been talking about a little bit at work recently is "why do we study exoplanets?'"It's an interesting question, and one to which different people give different answers. Everyone has their own motivation after all, and it's been fun to hear what people say. Ultimately though I, and apparently several other members of my group, think that many exoplanet researchers are lying to themselves and each other. Not to cause harm or detriment, but because we think that 'admitting' the real reason will make other astronomers sneer at us, or sideline our careers. It's not hard to see how that comes about; there's an attitude in professional astronomy that we should be in it for the love of the job itself, and that we should be heavily invested (often emotionally) in our particular topic.

Leaving aside the rather pertinent point that that whilst a postdoc or PhD student that is, to some extent, dictated by what your boss/supervisor gets you working on, it's a ridiculous attitude in the first place. Some research is really very esoteric, and the idea that someone can genuinely have decided to work in astronomy because of some of the research that goes on is just mind-boggling. I'm sure there are such people out there, but in exoplanets I think a lot of people can trace their motivation back to a single, more 'normal' factor: science fiction.

At the interview for my current job, one of the questions that I was asked was 'how did you get interesting in exoplanets?' Or something like that, it might have been 'why do you want to work in exoplanets?' In any case, I started giving the standard spiel that I usually trot out about school, then my undergraduate tutor working in the area, etc. etc. Then I was stopped, and asked 'what's the real reason?' I'll freely admit that it took me aback, and made me reconsider what I was saying. I was giving the explanation that I thought I should give, rather than the what my motivation actually was.

So I told the head of the interview panel, who's now my boss, that it was because of science fiction. Star Trek, Star Wars, Dr. Who, and all of the books that I'd read as a child, teenager, and young adult. Which is true, it is. Yes, all of that other rational behind my decision was a factor as well. I didn't know that exoplanets actually existed until I met my undergraduate tutor and learnt what he worked on, for example. But my ultimate interest in space and astronomy, and the reason that when I decided to work towards a PhD I only ever considered exoplanet topics, is science fiction.

If I think about it, this image in particular from Star Wars: A New Hope was a big influence on me. The fact that

it was widely used in stories about the first circumbinary planet, even by astronomers, shows that sci-fi is a big motivating

factor for many people in the field. (Credit: dadsbigplan.com)

More specifically, and here is where I think the real self-deception comes in for a lot of people, it was because I wanted to find extra-terrestrial life. All of those stories with aliens in them, but there weren't any in reality. But I could have a job where I could contribute to knowledge that might someday lead to their discovery? You sold it to me inside of 30 seconds.

And that, I think, is how a lot of people started in this field. How the field itself got started, not that long ago really, in 1992/1995. Maybe not with the search for life itself, but certainly with the idea that we could find an 'exo-Earth'. (There's a great interview with my boss actually on the Warwick website, where he gives the line "it really is like Star Trek".)

Others might cite Star Trek: The Next Generation as their influence.

But for me I think it was more Voyager. (Credit: furiousfanboys.com)

What's really exciting is that we're now getting towards the point where we might feasibly do that. I know that the Kepler mission was sold, to some extent, with the idea that it would find 'Earth-like planets'. But that's pretty vague, and a second Earth was always going to be at the limits of what they could do. But they have found longer period planets that most other searches, and smaller planets, some of which might even be made of rock (the jury's still out in many cases). But ESA have just announced that they've selected the PLATO satellite as their next M-class space mission; this could actually find an Earth-mass planet, in an orbit that gives it potentially habitable conditions. Sadly it's not due to launch until 2024, but maybe now that we have the opportunity to find such planets some exoplanet astronomers will feel able to admit that they didn't get into research because of the science, but because of the prospect of aliens.