Putting a ring on it: Ben Pope on Saturn’s Rings

Our next curator is astrophysicist, Dr Ben Pope (@fringetracker). Ben recently completed his doctorate in astrophysics at Oxford University and is currently in Australia at the University of Sydney. We’ll be hearing from him about the use of Saturn’s rings as a telescope and the physics behind it, and during the descent of Cassini into Saturn. Here’s how Ben ended up in astrophysics.



I almost ended up in the humanities, as a matter of fact – I wasn’t sure what I wanted to do when I finished school, so I started a combined BA/BSc at the University of Sydney, and picked physics, maths, Latin and philosophy courses. I kept up the Latin for three semesters until when I went on exchange at UC Berkeley I had to choose either science or humanities; it was a tough decision and in the end I went with science, but it almost could have gone the other way. I probably wouldn’t have even taken science at university if not for the influence of Michael Bishop, the most wonderfully inspiring chemistry teacher. It was the most immense privilege to have this teacher who taught us quantum mechanics and Lagrangian mechanics – and also running clubs for hieroglyphics and Viking sagas, and being a truly kind and caring teacher. I wish everyone could have a teacher like that.


There is so much hidden in the electromagnetic spectrum beyond the limits of human perception, and what I love about science is how if you dig in with the right instruments, you can make incredibly precise measurements of very tiny or very distant matter. In terms of the astronomy I do, I’m ‘guided by the beauty of our weapons’ – I work on developing new techniques for observation and data analysis that can push to ever greater sensitivity, but I’m less picky about what we are actually looking for. I ended up in this field really because I met my Honours, Masters and postdoc supervisor Peter Tuthill, who introduced me to interferometry – by measuring strange-looking interference patterns you can get images of the actual surfaces of stars, dusty pinwheels, exploding novae, planets forming, black holes devouring stars – only by understanding the complex simplicity of light waves.


Currently I’m working at the University of Sydney to design a small space telescope to look for planets around the Alpha Centauri binary stars, by detecting the motion of the stars relative to one another as they wobble back and forth under the influence of a planet’s gravity. This is something that has never been attempted at this level of precision before – we will have to be able to measure the relative positions of these two stars on the sky to better than a millionth of a pixel. Half of the trouble is in designing a space telescope – and half in figuring out how we’ll analyse the data, as to achieve this precision we’ll need to invest almost as much in software as in hardware! This is a fun break from what I was doing for my DPhil in Oxford and what I’ll be doing as a NASA Sagan Fellow at NYU – looking for planets transiting the nearest, brightest stars using the Kepler Space Telescope. A planet passing in front of a star – like the Transit of Venus around our own sun – causes a dip in the star’s apparent brightness, and Kepler stares at hundreds of thousands of stars at a time to catch these fleeting events. It was designed to look at huge numbers faint stars at once to gather good statistics on the Galactic population of planets as a whole, and doesn’t have the dynamic range to gather good data on the nearby bright stars where we might hope to actually learn a bit more detail about any planets they host. I have been part of a collaboration to dramatically enhance the dynamic range of the Kepler camera and look at naked eye stars as bright as the Pleiades and Aldebaran.


Sometimes I wonder this myself, because a lot of the time writing image processing algorithms or time series modelling code it can feel like you are hacking away at obscure and complicated technology at a great remove from tangible outputs that help people’s lives. But then you ask the general public what they think – and it’s a huge relief. People are genuinely excited to learn about astronomy, especially young people. Astronomy is the science that addresses all the big questions: how did the Universe begin? Where did we come from? Are we alone? What is our place in the cosmos? And the answers are astounding – the Universe is vaster and older than our minds can easily grasp, and everywhere we turn our telescopes we find new and unexpected wonders. In all my outreach and teaching I find that it’s the lay public that teaches me how much astronomy matters.


I was recently the CAASTRO Astronomer in Residence at Uluru


Some of your readers, especially in the UK, may know me from television – I was a member of the winning team from Balliol College, Oxford in the 2016-17 season of University Challenge. Things were crazy for weeks after that, in social media, the newspapers, we were recognized at the pub, in cafes, and even once in a mosh pit. It has been a bit calmer in Australia!


I would probably spend some of the day reading a book, perhaps in a cafe, without looking at emails or writing code. I’d love to be out on the water, whether it’s Sydney Harbour or the local river I feel completely relaxed on and around boats. And it would be lovely to see some live music in the evening.


Please welcome Ben to Real Scientists!


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