Like Dr Betzig, I’m also from Michigan, eight years older, also grew up in the Detroit area and went to the Jesuit High School. Now, everybody of my generation who was male was going to be a scientist, and that was because of the space race, and sadly girls weren’t going to be scientists, just boys in those days, a terrible, terrible thing. So I had this interest in astronomy, and we had the chemistry set in the basement with all these sorts of things, and like Dr Chu, I had a family that was very well educated. Both my parents were college educated, my grandfather who had come from Italy as a child had gone to Boston University and become a lawyer. My Dad was a journalist. I was torn between science and journalism. When I went to the Jesuit high school in Detroit, they told me all the smart kids did Latin and Greek, and I wanted to be a smart kid, so I left science behind. I did the Classics major and then went on to Boston College to be a History major, but at the same time, my best friend from High School was a freshman at MIT and while I’d visit him at the weekend I found that MIT had tunnels you could explore, and pinball machines, and weekend movies, and most importantly, the world’s largest collection of science fiction. In order to read science fiction, I figured out a way to transfer to MIT, but I had to declare a major, and I new I was not going to be an engineer because the only thing I can make with a hammer is noise. And I knew I wasn’t going to be a Physics major because I had a classics background, I was a historian, but I found on the list of majors, Earth and Planetary Science, and I thought, planets, people have adventures on planets, so I checked that off. They let me in. To this day I don’t know why. After I arrived, I discovered I had signed up for the geology department, and I could not imagine anything more boring than looking at rocks. What are you going to do? There’s a rock, there’s another rock, what’s to study? But there was a professor there, a fellow called John Lewis, who had been a student of Harold Urey, who had been a student of G.N. Lewis, so he was well connected, and he taught a class about meteorites, and meteorites are rocks but they have fallen from outer space. They are pieces of space that you could hold in your hands. And he was a tremendously dynamic teacher and I got so excited that I would wake up every Tuesday and Thursday and jump out of bed eager to get to class to hear more about meteorites. I stayed on and actually did a completely theoretical-based thesis on ice and rock together, and what happens if you have a moon made of ice and rock, and is there going to be enough radioactive material in the rock to melt the ice, and in the process, at the end of my Master’s thesis, I had predicted in 1975 everything that Voyager discovered when it got to the icy moons of Jupiter in 1979, and all the basis of where my calculations came from where totally wrong. I had underestimated the heat input by a factor of 10, and underestimated the heat output by a factor of 10, but I came up with the right number, and at least gave them the right idea of what to look for. I also in the thesis ended by saying, ‘I will not go as far as to predict life in these oceans under the ice crusts of Europa, I will leave that for others, more experienced in such speculations’, making fun of Carl Sagan. This is, as far as I know, the first time in the literature anyone mentioned life in an icy moon in Jupiter, except I’m not the first person to predict it, I’m the first person to go out of my way not to predict it.

I was enjoying this so much that I was encouraged to join a brand new department at the University of Arizona in Planetary Sciences. I went there in 1975, worked with a few different professors, and eventually got a degree with a fellow named Randy Jokipii who worked in cosmic rays, on the electromagnetism in the early solar nebula and what are its effects – hardly any that we could find – but it took a thesis to work that out.

My real goal was to go back to Boston. I loved being in Boston; I loved being at MIT, so I was two years as a post-doc at Harvard, and then three more years as a post-doc at MIT, at which point I realised that five years as a post-doc meant that you’re not going to get a job. I was turning 30, and that Jesuit training came back to haunt me, “Why am I doing astronomy when there are people starving in the world?” And I couldn’t answer it, I’m busy trying to write theoretical papers that five people in the world will read and two of them are my enemies, why am I doing this? So I quit science and I joined the US Peace Corp, and I said “I will go anywhere you want me to go, do anything you want me to do, let me be useful”. They sent me to Kenya and within three months I was at the best high school in Nairobi, Starehe Boys Centre, that had laser labs and computer labs in 1982, and I was there for one term, and then they sent me to the university, where I was teaching graduate students astrophysics, and I thought, people are starving. The kids I was teaching all had jobs waiting at the Kenya Science Teachers’ College to teach the teachers to teach, to help the development, that was the logic. But that wasn’t why they wanted to know astronomy, because every weekend I would go up country with a little telescope and everybody in the village would come and look through the telescope and they’d see the rings of Saturn and they’d go ‘Wow’, and of course everybody back in Michigan when they see the rings of Saturn they go ‘Wow’, and has anybody here ever seen the rings of Saturn in a small telescope and not gone ‘Wow’? Because this is what human beings do. Because this is what separates us from well-fed cows, because this is the meaning of ‘We do not live by bread alone’. You also have to feed your soul, and that’s why you do astronomy, when people are starving in the world because they are starving for more than just something to fill their stomach.

Thrilled by this, I went back to America, got a teaching job a Lafayette College, a wonderful little school, broke up with the girl I was dating, which was the happiest day in both of our lives, because we were really not right for each other, a wonderful person but it wouldn’t have worked. And at that point, with my two MIT degrees, I did a mathematical calculation: if I met the perfect woman tomorrow, by the time we had a family, I’d be 40, by the time those kids were teenagers I’d be 65. Way too old. What’s plan B?

Well I had this Jesuit background, if I joined the Jesuits I could teach at a Jesuit school and never have to worry about tenure – not true, but I didn’t know that. So I joined the Jesuits and I discovered that plan B was really plan A: for the first time in my life I was content, I knew where I belonged, and when I was telling somebody the story of turning 40 and a family, they said, ‘Guy, 40 plus 15 is 55, not 65’, so the reason I became a Jesuit is that I don’t know how to add. Also, they didn’t let me teach at a Jesuit college, like I expected. Under obedience, they forced me, they ordered me without asking, to go to Rome, eat that terrible food we’ve been having, look at that horrible scenery, and, oh yes, live in the Pope’s summer palace, and my instructions upon arriving at the Vatican Observatory were ‘Do good science’.

Incidentally, we happen to have a collection of a thousand meteorites. Remember meteorites? Remember how excited I was with meteorites? What do you do with a collector’s collection of a thousand meteorites? We didn’t have the equipment to break them up, but I knew from my theoretical work that no one had actually measured their physical properties, the density, the porosity, the magnetic properties, the thermal properties, so knowing that it might take twenty years to do it, but also knowing I wasn’t under the pressures of a three-year grant cycle, or tenure, I had twenty years, so that’s what I’ve been doing for the last twenty years, and then the last five years turned it over to Bob Macke, who is a younger Jesuit brother who does the same thing I do, only better. And the collection, any data that you see in the literature now about the physical properties of space material, probably comes out of our lab.

There years ago Pope Francis assigned me to be the director of the Vatican Observatory. It’s a five-year term renewable until I get sick of it, so I’m in year three of it but I’m enjoying myself too much, so I expect to be in for a while. It has been my joy to continue to do, and to tell the new people what I had been told, “your job is to do good science, and you have as much time and as many resources as you need”, and the science I do, physical data collection, may not get me the Nobel Prize, but it is data that will still be true one hundred years from now, which is probably more than you theorists can do. Thank you very much.