The Pope’s Astronomer: In Conversation With Brother Guy Consolmagno

By Heather Abraham  

Religion Nerd’s In Conversation with Series continues with a feature interview with the Pope’s astronomer, Brother Guy Consolmagno.  A native of Detroit, Michigan, Consolmagno received a master’s degree from the Massachusetts Institute of Technology in 1975 and his Ph.D. from the University of Arizona in 1978, after which he lectured at Harvard College Observatory and MIT.  In 1983 Consolmagno joined the Peace Corps, serving two years in Kenya teaching physics and astronomy. 

In 1989 Consolmagno entered the Society of Jesus, taking his vows in 1991, and was assigned to the Vatican Observatories where he conducts research on the Vatican meteorites and studies the evolution of planets. Consolmagno spends his time as astronomer and curator of the Vatican meteorite collection between the Vatican Observatory in Castel Gandolfo, Italy and the University of Arizona’s Mt. Graham International Observatory where he observes and studies asteroids and Kuiper Belt comets.  Brother Consolmagno is author (and editor) of many books and journal articles including:  God’s Mechanics: How Scientists and Engineers Make Sense of Religion, The Heavens Proclaim: Astronomy and the Vatican, and Brother Astronomer: Adventures of a Vatican Scientist Wecome to In Conversation with Brother Guy Consolmagno

HA:  When I became aware that the Vatican had an observatory, I was intrigued.  This is not something that most would associate with the Vatican.  I think it would be helpful for Religion Nerd readers if we begin this conversation with a brief historical exploration of the relationship between the Catholic Church and science.  

  • Q:  What is the historical relationship between the Vatican and the study of astronomy? 
  • Q:  How do you understand the Galileo affair? 
  • Q:  What is the general function of a present day Vatican astronomer? 

BGC:  The history of the Vatican and Astronomy goes way back… and of course, let me plug our popular coffee table book, The Heavens Proclaim: Astronomy and the Vatican (2009, Our Sunday Visitor Press), which goes into this in great illustrated detail. 

The reform of the calendar in 1582 is one obvious key moment. That’s when the Pope [Gregory XIII]  hired a committee of astronomers to work out a simple way to adjust the old calendar, which had allowed the seasons to slip by—by ten days since Julius Caesar had established it. The astronomers he hired also had to work out a formula for determining Easter that could be used anywhere in the world. This was the age of exploration, remember; the old rule for Easter as the “first Sunday after the first full moon of spring” wouldn’t work anymore, since for the first time people had to worry about whether a Full Moon occurred on a Sunday or a Monday in their part of the world. 

But even before then, astronomy was one of the seven subjects that everyone was expected to master before you could go on to study philosophy or theology in the medieval universities, founded by the Church.  And there are gobs of places in scripture, such as the Psalms, where the beauty and vastness of the heavens are used to proclaim the greatness of the Creator. 

The idea of a “split” between science and religion is a fairly modern one, mostly dating from the 19th century and the rise of professional scientists who were making a living independent of the Church. That’s why the Church specifically started funding an observatory, in 1891, to show the world that it supported science. Our duties at the observatory today are simply to “do good science” — we’re left to decide for ourselves what science to do — as a way of continuing to demonstrate that support. 

Before then, the Church acted as the scientific “establishment” that had to test and judge new ideas, just as scientific journals and referees do today. It was by no means opposed to new ideas; just look up Nicholas of Cusa, a 14th century Cardinal who proposed that there were countless inhabited planets in the universe. The fact that the Church was interested in Galileo in the first place is evidence that they were directly involved in nurturing and promoting science.

The Galileo affair is of course a lot more complicated than you usually hear. If you want to know more, read the documents in the case, including the transcript of the trial, gathered in English translation in Maurice Finocchiaro’s book The Galileo Affair (1989, U of California Press). The facts don’t make the church look any better, mind you, but you realize that what happened to him was almost certainly more tied up with the politics of Rome during the 30 Years War than with anything involving his science.  For most of his career, Galileo was praised by the Church and even after his trial, he was the guest of the bishop of Siena and treated well. 

HA: One of your responsibilities is as curator of the Vatican meteorite collection; could you describe the specific nature of the research in which you are involved?   

BGC:  When I got to the Vatican Observatory in 1993 I found that it had a wonderful collection of meteorites assembled in the 19th century by the French nobleman, the Marquis de Mauroy. It had a little bit of almost everything, but not a whole lot of any one meteorite. At that time, I knew that chemical studies were well advanced in many labs using the kind of expensive equipment I could never afford. But nobody was doing physical studies: density, porosity, thermal properties… the kinds of measurements that are essential for understanding the evolution of asteroids and other bodies that might be made up of meteorite-like material. 

I started doing density measurements in 1996, with a modified Archimedean technique — looking for the displacement of a fluid to find the volume of the sample — that used glass beads instead of water or other potentially contaminating fluids. I got the idea while pouring sugar into my cappuccino during one of our coffee breaks at the Observatory. We now have a student who’s just finished measuring more than 1000 meteorites around the world with this method. We also look at the magnetic susceptibility of meteorites, their thermal conductivity, and we’re launching a program to measure heat capacities. These are all measurements that surprisingly nobody had much done before. 

And they turn out to have important consequences that surprised us. For example, the density of meteorites are 30% to 50% higher than the density of the asteroids they come from. Asteroids are not rocks out in space — they’re rubble piles, with big holes and cracks… probably large enough to hide the Millennium Falcon, I bet! 

HA:  There are those that see religion and science as polar opposites—antagonistic if you will, and yet you represent a successful marriage of the two.  How do you understand the relationship between science and religion?   And, is your study of the evolution of planets an extension of your religious convictions?  In other words, do you understand your work as an opportunity to understand God? 

BGC:  I reject the idea [of] two different kinds of truth, or even two different regions of knowledge, one labeled “science” and the other labeled “religion”.  Nor can you say, such-and-such must be true in science because it says so in the Bible, or that God cannot do this or that because it violates some scientific proof. The Bible is not a science book. (Science books go out of date, very quickly; the Bible does not go out of date, anymore than Shakespeare or Plato go “out of date”.  It’s a different kind of beast.) Likewise, to use your science to prove, or disprove, the existence of God makes your science more powerful than God, which is a logical contradiction. 

So it’s not that science and religion lie side by side; but that one underpins the other. 

Instead, I have to realize that my science is only possible because I make certain assumptions ahead of time about how the universe behaves.  I have to assume that laws exist, before I can start looking for them.  I have to assume that the human brain is capable of understanding those laws, or else this is all a waste of time.  And, I have to assume that the universe is somehow worthy of me spending my life getting to know it. 

The whole idea that we live in a universe deliberately created by God, a universe He called Good, is the fundamental assumption that has allowed western society to promote — and pay for — the study of the physical world just for its own sake. Ultimately we are not astronomers just to figure out when to grow crops (or make better Teflon!) but because the stars themselves are fascinating, and worthy of study, in and of themselves. 

The soundbite answer: My religion tells me God made the universe. My science tells me how He did it. And by seeing how He creates, I come to be a little more familiar with the personality of the Creator. 

HA:  In your book, Brother Astronomer: Adventures of a Vatican Scientist, you explore the possibility of life on other planets.  The following is a quote in which you discuss the possibility of the presence of ETs in the Universe, 

Frankly, if you think about it, any creatures on any planets, subject to the same laws of chemistry and physics as us, made of the same kinds of atoms, with an awareness and will recognizably like ours, would be at the very least, our cousins in the cosmos.  They would be so similar to us in all the essentials that I don’t think you’d even have the right to call them aliens. (p152-53)  

If life, in any form, but most specifically ETs exists elsewhere in the universe, what is your understanding of our cosmic cousins in relation to Christian theology?  

BGC:  This is not in the realm of science, not yet; it’s science fiction.  And I started out as a science fiction fan long before I was a scientist or a Jesuit.  Science fiction is precisely the place where we can play with these ideas, ask the what-if questions, and see how it plays out. The point is not that we have an “answer” at the end of the day, but that we grow to appreciate what the questions really mean.  When you speculate about aliens, you’re really asking what it means to be human. When you wonder about what “salvation” would mean to another intelligent species, you’re finally coming to grips with what it actually means to us. 

So, ultimately, though I can speculate as well as anyone, at the end I have to say: I don’t know. I’d love to find out!

HA:  To borrow a question from your chapter title (which was introduced to Religion Nerd readers in Kenny Smith’s article, The Arrival of Extraterrestrials on the American Religious Landscape), Would You Baptize an Extraterrestrial

BGC:  Would I baptize an extraterrestrial? Only if they ask!    

HA:  Creationism and intelligent design—these are hot button terms in the United States.  Could you elaborate on your understanding of these terms as both a Catholic priest and Scientist?  

BGC:  These are terms that have so many different meanings to so many different people that I try to avoid even using them. 

If you use anything in science as your reason to believe — or not believe — in God, you’re on treacherous ground. Science keeps developing, and what we understand tomorrow may be substantially different from what we assume today.  Just look at how physics now is so different from the mechanical viewpoint of the 19th century. 

On the other hand, if your belief in God comes from personal experience, prayer, the experience of love and beauty in your life, the testimony of people you trust writing in Scripture or passing on tradition, then you already know God exists.  With that knowledge, you can then delight in seeing a familiar hand at work in the physical universe. 

But the faith comes first. 

HA:  In wrapping up this conversation, I would like to ask a couple questions that are lighter in nature. 

  • Q:  In 2000, the International Astronomical Union honored your work by naming an asteroid after you, 4597 Consolmagno.  Is this an asteroid that you discovered?  How cool is it to have an asteroid named after you?
  • Q:  I understand that you are a science fiction fan.  What are you favorite sci-fi books, movies, or television series?  

BGC:  The asteroid was discovered by a friend of mine, Bobby Bus.  It helps to have friends in the business!  For example, there are 35 craters on the Moon named for Jesuits (none for me, thanks — you have to be dead before a crater can be named for you!).  That happened in no small part because the guy who made the Moon map with the nomenclature we use today was, himself, a Jesuit priest, Giovanni Battista Riccioli. 

And, yes, I love science fiction… both space opera and fantasy. Some of my favorite contemporary authors include Lois McMaster Bujold, Gene Wolfe, Connie Willis, P. C. Hodgell… Some of them specifically treat on religions themes, others don’t, but in every case a good SF or fantasy story has to have a moral center against which the actions of the characters can be judged.  And one of the best things of being an astronomer at the Vatican is that I have been invited to serve on panels at a number of SF conventions where I’ve gotten to meet a number of these authors!

Nerd Note:  The purpose of this interview was to introduce Religion Nerd readers to the Vatican Observatory, the Catholic Church’s relationship with the sciences, and Brother Consolmagno’s work.  I would love to do a follow up interview with Brother Consolmagno, making more in depth inquiries as to the nature of his work and vocation.  If, after reading this brief introductory interview, you have any questions you would like to ask, please contact me at and I will add them to the list of possible questions.

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