Why is the Pope's astronomer here in New Zealand? And why is he on Great Barrier Island, of all places, and talking about aliens, of all things?
Vatican Observatory director Brother Guy Consolmagno - an M.I.T graduate and native of Detroit, Michigan - isn't too different from most scientists, except for the fact his boss happens to be the leader of the Catholic Church.
An expert speaker on a panel at a festival on Great Barrier Island today, Consolmagno sat down for a chat with Herald science reporter Jamie Morton about faith, the universe, and little green men.
Q. So tell me about the Vatican Observatory. Why is there one?
A. There's a short answer and a long answer.
The Vatican really got interested in astronomy, professionally, back in the 1500s, because it wanted to reform the calendar.
Everybody knew the calendar was out of kilter: in the 1500 years since Julius Caesar had put it together, it was off by 10 or 11 days - so how could they fix it?
The other thing they wanted was an easy was to calculate the date of Easter, especially for people travelling far away from Europe.
So they hired a bunch of astronomers, and these included Jesuits who were running the Roman college in Rome, and a fellow named Christopher Clavius.
If that name sounds familiar, the Clavius Crater named for him on the Moon is where the moon base was in the movie 2001: A Space Odyssey.
In those days, astronomy was a branch of mathematics - you calculate where things are in the sky - and they kept doing that at the Roman college for hundreds of years.
You just look at who was publish sing scientific papers in those days - it was either a medical director, or some nobleman, or a reverend, because who else had the education and the free time to go out and gather all of this information?
There's a reason why clerical work is called so, because it was the clerics who did it.
At the end of the 19th century, there were lots of things happening in our culture: there was this idea that science and technology was going to solve all of our problems, and all of that led the Church to getting a bad rap about science.
The other thing happening was the unification of Italy, and the Vatican, which had been the central part of Italy, the Holy See, was reduced to just the area around St Peter's Church.
They wanted to demonstrate and insist that they were independent of Italy, which didn't recognise it yet.
In 1891, Pope Leo XIII, a very forward-thinking pope, decided he was going to found a national observatory, which was going to two things.
One, it would show the world that the Church supported science, and two, it would demonstrate that we were a different country than Italy.
So, in a sense, it was for political reasons and apologetic reasons, but over the years, the tenor has changed.
Certainly, it's still true that we have to demonstrate to the world that the Church supports science - but the people we have to demonstrate that to mostly are those in the pews.
We have to remind them that science is good, science is fun, and if you believe that God created the universe, then studying the universe is itself an act of worship.
If you love someone, you love the things they make - just ask a mother who puts pictures that their children create on the refrigerator - so if you love God, you're going to love the things God made.
This is going to make you want to know more and more about how the universe actually functions.
Deeper than that, there's a sense that understanding science, and especially astronomy, is a great way to pull yourself out of ordinary, day-to-day life - you recognise that the universe is much bigger than your concerns about traffic, your dinner that night, or your job.
Q. But surely, you can understand why people argue that faith and science are two concepts at odds?
A. Nowadays, yes.
And the reason that people think they are at odds is because most people stop learning about science when they're 12, and most people stop learning about religion when they're 12.
What does a 12-year-old know about science?
It's a big book of facts, and they feel the same about religion; they learned it at Sunday school, so it must be true.
But when you get beyond all that stuff, you learn that science itself is not about collecting answers; it's about asking the right questions, and getting used to concepts.
It's the same way I feel about anything that you love.
Spending time with the universe is a great way of getting to used to creation and the creator.
Q. Do you have a direct relationship with the Pope?
A. The Pope appointed me: he got my name from somebody else.
I don't meet with him every week or every month, but we do write up a report every year of what we've done, what the science is and how we've been talking about it to the public.
Pope Francis has been to visit us, and he actually knew the former director, who was also from Argentina.
He's certainly happy to support the work we do, especially with students from the Third World, but he pretty much leaves us alone to do our thing.
When there's an issue that would come up, or where we'd need something from him, I have the option to ask for an audience any time.
But frankly, such an issue hasn't come up yet.
Q. Pope Francis does appear particularly interested in science: I note he has pleaded with countries to act on climate change.
A. Climate change is an issue to him not only because of the science - he has a background in chemistry - but it's also a faith and justice issue.
Who gets hurt the most by climate change? It's the poor.
He's also recognising that crimes against the environment are sins.
The classic line is that there are two books: there's the book of scripture and the book of nature.
If you are messing up the environment, it's like writing graffiti in The Bible - you are destroying something that God is trying to use to talk to you, and it really is sinful.
The other thing is that the ultimate answer to climate change is not going to be a technological answer - although God knows we need the technology - because the real crime isn't a technological one, but a crime of the heart.
It's the selfishness, it's the same old sins that have always been screwing us up: the big seven haven't changed in 2000 years, and no one has invented a new sin lately.
But I also believe that the ability to do science, and the need to teach science to as many people as can handle it is also a faith and justice issue.
A person who is technologically competent knows that problems can be solved - even really big ones - if you break them into solvable pieces.
I know from my time working with the poor in Africa that if you don't believe problems can be solved, then you are more likely to despair or to give up.
Q. What standing does your observatory have in the astronomy community?
A. We have quite a bit of respect, for a couple of reasons.
What we have going for us that's really special is that we are not confined to a three year grant cycle, or a six year tenure cycle, and we aren't competing with other astronomers for money.
This not only means that we can be friends with everybody, but that we can do science that needs to be done and that no one else is able to do.
I've been working for 20 years in a meteorite lab, collecting data on the density and magnetic and thermal properties of meteors, which contributes toward our understanding of how asteroids work and how planets work.
You can see the role that members of the observatory have always played in the International Astronomers Union and in the American Astronomy Society.
I'm a past president of the Division for Planetary Scientists, which is basically half the planetary scientists in the world, and I got that job from an election.
There's only half a dozen of us at the observatory, yet we are deeply involved in the politics of astronomy, so clearly the observatory is known and recognised.
Q. Getting to the reason you're here: to talk about the search for other life forms in the universe. Astronomers and cosmologists are interested in big questions, like what happened during the cosmic dawn, at what rate is the universe expanding, and what is dark matter - is the topic of aliens therefore seen as trivial or a distraction?
A. Not really, no.
I read a great book on astro-biology a couple of years ago, which makes the comparison between where astro-biology is now and where cosmology was 30 years ago.
The difference is that when you suddenly have the data, then you can turn the science from speculation into something more serious.
And actually, we have the data - we don't have evidence of life elsewhere yet, but we have more data than we've ever had before about what life can survive here on Earth, in extreme environments, and what the environments are on other planets.
That means we can raise the question, not is there life on [Jovian moon] Europa or under the surface of Mars, but that if there isn't any, then why not?
We still have to look to confirm whether there is or not, but either way, it's going to be an interesting answer, because we now understand enough to realise that a yes or no answer from these different environments is telling us something fundamental about what life is and how it works.
And that makes it a very exciting time to be a scientist in this field.
Q. If we do happen to find life in the next century, is it a fair bet it's likely to be some form of microscopic cyanobacteria, and somewhere in our own solar system, rather than anything intelligent out beyond the galaxy?
A. I know what we are looking for - and we are looking for carbon-based life that has chemistry similar to what we recognise as life on Earth.
That's a sensible thing to look for, because at least we know what we are looking for.
But the only way I think we will understand where life is or not, is not specifically only looking for life, but also understanding the rest of the universe well enough to know that these kinds of signals come from this kind of star and that one.
Only then will we be able to see a kind of signal that we can't explain.
And that means you can't search for extra-terrestrial life in isolation from the rest of science: it has to be an element of wider science, that we understand the chemistry and the physics of the universe, in total.
It's an interesting time to be an astronomer, because we've got these large-scale projects kicking off.
The US is involved in a new telescope project in Chile, and you've got the Square Kilometre Array radio telescope and the James Webb Space Telescope being constructed, and surely our rate of being able to make big discoveries must be about to increase quite dramatically.
I wouldn't be surprised if we find microbial life in our solar system in my life time.
I think that would be perfectly reasonable - and I would not be surprised, if 20 years from now, with the next generation of telescopes, that we were able to find bio-markers in atmospheres of planets around other stars.
I mean, we can barely see other planets now: but if you are really clever, you can subtract the light from the star, and from the light from the planet, and even though you can't see it, you might find there's evidence of ozone.
And then you can ask, do you see evidence of chemicals that are grossly out of equilibrium, suggesting there's something on that planet doing something funny, like making oxygen?
I certainly would think that in 20 years from now, we will have strong evidence of certain planets around other stars that make us think, maybe there's life out there.
But do I think we are going to get a message from space?
It's true that the further away we look, the more planets there are out there, and the greater the possibility is that there might be intelligence: but the further away you look, the harder it is to have any kind of conversation.
Q. What are the big misconceptions that people have about this area?
A. People think it's easy to get to the stars, and that comes from watching too many science fiction movies.
And I love science fiction movies; they're what got me into this field.
But, you know, if we could confirm there was a planet around our nearest star, Proxima Centauri, and we sent a space ship there with our modern technology, it would take tens of thousands of years to get there.
That sense of being able to communicate and travel is a lot harder than people appreciate - even going to Mars is a lot harder than people appreciate.
I really don't think we are going to have a crewed mission to Mars in my lifetime, and I would hope that we don't; I don't think our technology is ready for it.
We went to the Moon too soon: I'm glad we did, but it's a tragedy that it's been 50 years since we were there.
And I really think the Moon is a much more interesting place for us to study in the near term, and it will teach us how to prepare ourselves to go to other planets.
But it's going to be a lot slower and a lot harder than people think.
Q. In spite of probability, do you suspect there's still that lonely chance that we're the only ones out here in the universe?
A. There was an American cartoonist years ago, Walt Kelly, who had a marvellous cartoon on the topic.
He said, you know, maybe out in the universe are creatures more intelligent than we are, or maybe in all of the universe, we are the most intelligent creatures: either way, it's a sobering thought.
Q. You've come all the way to Great Barrier Island, from the other side of the world, for this visit: would it rate as the most unusual place you've been?
Clearly, the weirdest place I've been is Antarctica.
That felt like not just another continent, but another planet: it actually gave me a sense of what it might be like to be an explorer on another planet, even though you can at least still breathe the atmosphere there.
One of the most unbelievable places I've been - the place that I kept having to pinch myself, wondering if I'm really there - is the place where I lived for 18 years, where you could see Pope John Paul II out your window every morning.
I never got used to that.
But Great Barrier Island is certainly unique - and yet it's wonderfully familiar.
The people have been so friendly and, in a sense, being in a place where people speak English, makes you feel at home.
I live much of the year without speaking English, and I've never got used to that.
But I've been to every continent doing science, I've been around the world a zillion times, and it's never got old.
It's never become boring, and yet, I can't say I've had quite the view I've had here on Great Barrier Island, with the ocean, the mountains and the islands beyond.
It's magic, it really is.
The great thing about being an astronomer, is first of all, no matter where you are, you'll find something wonderful to look at: and no matter where you are, you'll find something familiar to look at.
I went off to Africa as a young man, and I was terribly homesick.
But when I saw the stars at night and I recognised the same stars I grew up with, along with new stars I'd never seen before, I had that sense that the universe is an exciting place to explore.
I know now that I'll never be away from home, because I'm at home in the universe.