Distant Wanderers

In an interview on Life Beyond Earth

Let’s move on to Distant Wanderers by Bruce Dorminey.

Bruce Dorminey is a science writer and he wrote this book several years ago. He is looking into the early days of exploration for extrasolar planets. Bruce is interested in the same thing that many of us are interested in these days, looking to see first of all if there are planets around the stars, and eventually to determine if they are inhabitable planets. I feel like I am picking up where Bruce left off and talking more about what it takes to have a habitable planet.

It’s a competitive business isn’t it?

Yes, most of the 400 or so planets that have been found were found using ground-based telescopes, using a particular technique called the radial velocity technique. What you are doing with this method is looking for the back and forth wobbles of the star in your line of sight. There are several different groups doing it now. There is a group in the United States that used to be Geoff Marcy and Paul Butler working together. There is another group over in Switzerland – Michel Mayor and Didier Queloz were the initial leaders of that group. Those two groups were and still are competing to find the most planets from these observations.

There are two schools of thoughts among those looking for life on other planets: the optimists like you and Carl Sagan, who we will discuss later, and the pessimists like the authors of Rare Earth. What arguments have you and the optimists come up with to show that there is life on other planets?

What I am most optimistic about is that the chances of finding other Earth-like planets are good. That means planets that are small and rocky with atmospheres and with liquid water on their surfaces. There are many conditions under which planets like that can form. Now, whether any of those have life is still a matter for speculation. We only have one origin of life and we don’t know whether that happens on every planet when the conditions are right or whether that only happens once in a blue moon.

And do you think that if such planets do exist, given what is going on here on Earth, we can conceivably go and live on them?

It’s not impossible. If you found a habitable planet around a relatively nearby star like Alpha Tauri, you might not send people themselves but we could code up genetic sequences and human genomes and put it on computer chips to send there. Then you would have to figure out how you raise a civilisation from scratch with no parents ­– but if we get good at making robots maybe you could do that.