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Molly Magid: Welcome to UC Science Radio, where we interview a range of postgrad students to tune into the fresh voices entering the world of science and learn what sparked their passion. I’m Molly Magid, a Master’s student in the School of Biological Sciences.

Today I’m talking with Rosemary Dorsey, a PhD student studying astronomy. Her research focuses on solar system science and characterizing small body populations. She also engages in science outreach to inspire other students to study physics.

Kia ora Rosemary, welcome to UC Science Radio.

Rosemary Dorsey: Thanks for having me!

So you’re studying astronomy, but specifically could you what is your research about?

RD: My PhD research that I started working on last July is on planetary science, which means small rocky objects like the planets in our solar system, but actually our solar system contains more than just eight planets, it has all sorts of small rocks like asteroids and comets, and those are the ones that you would know about. But there's also a bunch of rocks and stuff outside of Neptune's orbit, which we call the Kuiper belt, and there's all sorts of objects in there which look very different from each other, and we want to know why they look so different close to each other. And we think that their differences are probably due to how the solar system formed, so by finding out more about what's in our solar system, we can figure out how it actually got there.

So these objects have been there since the solar system formed?

���:��Yeah, so most of what we have in our solar system is from when the solar system formed. We will have captured some material from the outside, but what happens is there's a disk of stuff and then everything moves around and clumps together and lots of it gets ejected. So what we have today are remnants of what the solar system formed from. But the different properties of the objects we have left show us how the solar system evolved. We know some of the planets moved around and those planets moving around shifted some objects and made them different, so looking at those objects we can figure out how those planets moved, when they were moving.

How exactly are you going about studying this? What are some of the tools and methods you use to look at these objects?

RD: Well it's quite hard to see some of these objects cause Neptune's orbit is 30 astronomical units. So, and I'm talking about the Kuiper belt, goes from 30 to 50 astronomical units, which is quite far away. One astronomical unit is defined as the distance between the sun and the Earth. So the distance of the Earth's orbit from the sun is one astronomical unit, so you times that by 30, that's how far away Neptune is from the sun.

So some of these objects, because they're quite small and quite far away, are hard to see. So one of the big advancements that we make is finding more of these objects, cause if we find more of them, then we know more about the population as a whole. And so one of the big, exciting upcoming surveys is the Legacy of Space and Time Survey (LSST), which is a telescope based in Chile, and it's going to do a ten year survey and it's supposed to find about 10 to 500 times as many objects, of different types of objects, in our solar system. So it's supposed to be really good for solar system object discovery, so hopefully after this survey, we'll find more objects than we had before. And so we'll be able to find out more about them.

What is the most fun or exciting part of your work?

RD: The main thing I find interesting is just how much we can figure out from where we are. Like that's the most interesting part of why I think astronomy is cool, is just every other science or every other field of something, you generally have to be on Earth looking at something on Earth to do it. And, sure, you could look at the Earth and figure out more about it, and therefore how it formed, but lots of the stuff we look at in astronomy is so far from the Earth, we can't ever possibly touch it. All we're doing is looking at it from afar, and we can find out so much about stuff. And that's what I think is very cool.

And you've done some science outreach to the community, could you talk a bit about that?

RD: In 2014, in my thirteenth year, year-13 of high school, I went on the Aurora astronomy school, which is run by UC every year, and we got to go to Mt. John and look at the telescopes, and we got some lectures at the University of mini��ý. And I had no knowledge of anything astronomy-related besides, you know, there's eight planets in the solar system. And so all of those lectures, I knew nothing about what they were saying, and it was just like "Oh my gosh there's just so much information that I did not know before. There's so much to learn, so much new stuff."

And so that inspired me to do astronomy, and the last couple of years, I've been able to a student assistant on the Aurora school camp, now that I'm a postgraduate student. It's now called the Elaine P. Snowden Astronomy Camp, but I've been lucky to be selected as one of the helpers for a couple of years now. So that's really fun, so I get to see a whole new bunch of year-13 students who are interested in astronomy or science, because not all of them go on to do astronomy, but they might be interested in some scientific field and they're really passionate about their studies and everything.

And we get to introduce them to UC and show them around the campus, and then we go down to Mt. John and we take them up to the mountain for a couple of nights and show them the telescopes, show them how they work. Luckily, this year we had a nice night of weather, so they actually got to open the telescopes, cause if it's cloudy, there's no point in opening them. So yeah it's really fun showing them around and they ask lots of questions.

So you talked a bit about this just now, but what was your path to this research?

RD: It mostly came from the Aurora school. I hadn't had much experience with astronomy in high school. We didn't do the Earth and planetary science NCEA paper, so I had no idea about it.

I remember going to a lecture from the director of JPL, he came to New Zealand and he was giving a public lecture, and I thought "that sounds interesting, I’ll take my dad with me.” So we went to this lecture, and he explained the massive engineering feat of landing a rover on Mars, and all of the things that could go wrong, and all of the things that you have to think about when putting a rover together and putting instruments on it, and then you’ve got to think about how Mars is different from Earth, and also you're flying this thing for how long to get there. And it was just all really fascinating that despite all of these problems that needed solving, we still managed to get a rover on Mars, and with a twenty-minute signal delay. So we can't actually communicate with anything on Mars immediately, like we can on Earth, because it's so far away, we have to wait for the signal to arrive and then come back, and so you can't actually react to anything that goes wrong for twenty or forty minutes, which is a long time for things to go wrong, so it's very impressive, listening to him talk about how successfully they landed the rover, with all this you expect so much go wrong.

So I was really inspired by that, and then I went home and was telling everyone I could about it. And my parents had this book in their house called The Planets by Dava Sobel, and so I picked that up and started reading it. And it was basically, it was a bit of history on like how each of the planets was found and discovered, and a bit about the Greek gods and Roman gods that they were named after, and that was very cool, and so I was like "oh this is all just very interesting."

And then I got the opportunity to go on the astronomy camp, and it was just so much knowledge I was like "I need to learn more about this, I can't just stop." I found it much more interesting than, all of the physics I'd been doing was good, but this was so much more interesting, and so that was what really drove me to astronomy.

So, my last question for you is, if there was one big change that could come out of your research, what would that be?

RD: So a PhD is supposed to be a unique contribution to your field, so in order to get a PhD I have to do that. And one of the things I would like to do is publish a paper, I haven't done that yet in my postgraduate study, so that would be very cool. So that would have to be if I do some analysis and I find a result which I think is really interesting and makes an improvement on the knowledge we already have, and then I would ideally publish that and then all the science community can look at that work. That's one of my goals, is publish something to say: "look, this is what I did and here's what we found out, and this is new and different." And that would hopefully improve what we know about the small body populations in our solar system. And therefore maybe change what we think we know.

Thank you so much for talking Rosemary!

RD: Thank you very much for having me.

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