It hard to think of a more influential modern planetary scientist than Carolyn Porco, the leader of the imaging team for NASA’s Cassini mission exploring Saturn. But before Cassini, Porco was involved in Voyager missions, and she’ll be leading up the imaging team for New Horizons.
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Announcer: This episode of Astronomy Cast is brought to you by Swinburne Astronomy Online, the world’s longest-running online astronomy degree program. Visit astronomy.swin.edu.au for more information.
Fraser: Astronomy Cast Episode 362: Carolyn Porco. Welcome to Astronomy Cast, our weekly facts-based journey through the cosmos where we help you understand not only what we know but how we know what we know. My name is Fraser Cain. I’m the publisher of Universe Today and with me is Dr. Pamela Gay, a professor at Southern Illinois University, Edwardsville and the Director of Cosmoquest. Hey Pamela, how are you doing?
Pamela: I’m doing well. How are you doing Fraser?
Fraser: Great. So do we have anything that we want to promote or let people know about this time around?
Pamela: It’s the International Year of Light and I’m far too enthusiastic and over-caffeinated. So starting January 1, 2015 there is a global celebration of the International Year of Light. There is an astronomy cornerstone called Cosmic Awareness and we’re working to get everyone to understand that light pollution bad, light from stars good. Let’s celebrate light from stars, reflective light from stars off of planets, and all of the information that we get back in the form of radio light from spacecraft and say down with light pollution.
Fraser: Down with light pollution. And then the other thing is if by the time you see this comet Lovejoy maybe is going to be a comet you can see with the unaided eye in dark skies. I think it was getting to a magnitude four.
Pamela: It’s trying.
Fraser: Yeah, so this is it. This is the comet that the universe owes us and I’m a little underwhelmed. I want another Hale-Bopp.
Fraser: I want a Hyakutake. I want the icing that we were promised. So this is a good start. Okay, so let’s get rolling.
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Fraser: So it’s hard to think of a more influential, modern, planetary scientist than Carolyn Porco, the leader of the imaging team for NASA’s Cassini mission exploring Saturn. But before Cassini Porco was involved in the Voyager missions and she’ll be leading up the imaging team for New Horizons. And before we get going in this show I just want to apologize in advance to Carolyn Porco for the mistakes that we’re going to make because we’re done our research, we’ve done the best we can, but I’m sure we’re going to make a few errors. This whole thing just comes from such a sort of deep level of respect and admiration for the work that Dr. Porco does; literally the work on Voyager, the work on Cassini, the work we’re going to be seeing on New Horizons. So I apologize in advance Dr. Porco because she will tell us.
Pamela: She will. And this is the one scientist in this series that I’ve never heard speak. I’m not quite sure how this has happened. She’s a frequent public speaker but it’s just managed that I’m either just never at the right conferences or something.
Pamela: So I don’t personally know her other than occasionally sharing tweets and being on the same lists, and that doesn’t mean I know her it just means our names have been listed in proximity on the internet.
Fraser: Yeah. And I actually shared an anecdote at sort of the end of the last show in the questions and answers period, which by the way at the end of every episode when we do our live show we handle all the Q&A at the end of the show. So if you want to get your questions answered just come and watch the live show that we do. You can get information on that from our page on Google+.
Anyway, we answer questions and I was talking about Carolyn Porco and sort of my first interaction with Dr. Porco was she literally taught me how to properly attribute images that come from various space agencies. So whenever I would post an image of Cassini’s images of Saturn I would go Image Credit NASA JPL and then Dr. Porco reached out to me and said, ‘You’ve got to include Space Science Institute because we’re the people who are actually taking the pictures and processing them and doing a lot of the work.’
And so at that point I understood the chain of all of the – there’s NASA, and there’s JPL who works for NASA, and then there’s Space Science Institute, and there’s the Cassini imaging team. And each of these people have a hand in bringing you this final image that we get a chance to see. And so since then I’ve gotten way better. So that’s my interactions with Carolyn Porco. So who is she?
Pamela: She’s a scientist. But seriously to give a better background she is an imaging scientist who’s been working on studying objects in the outer solar system literally since I was playing with Barbie dolls. It’s one of those times where every once in awhile you get told, ‘I’ve been doing this since you were’ and there’s always like playing with tricycles, playing with blocks, playing with Barbie dolls. She finished her Bachelor’s Degree in Science in 1974, when I was still in diapers. She finished her Ph.D. in 1983 working on the Voyager spacecraft at California Institute of Technology where she was working on the rings of Saturn when I was a child with Barbie dolls.
And she has continued throughout the entirety of my lifetime to contribute to a lot of the different spacecraft that have inspired me throughout my life. When I was a kid, as I’ve talked about in the show before, it was the Voyager mission’s data that really inspired me, that my parents more than once let me stay up late to watch the data coming back. And she was one of the scientists that helped understand the rings of Neptune and the rings of Uranus how they’re shepherded by moons. She worked on the Saturn data for her dissertation.
All of this early, amazing work, all of this done in the years right after finishing her Ph.D. put her in a position that when the Cassini mission began its planning stages heading up towards launch she was selected in 1990 to head the imaging team for the Cassini-Huygens. This meant that she’d be the person in charge of the group of humans dealing with the pretty images that everyone sees in the news. There’s lots of different instruments on Cassini that do lots and lots of different science, but it’s those images that everyone uses as their background on their computer, as the beautiful color images on the covers of magazines. She’s the person that makes those happen.
Fraser: I don’t think people really realize how these missions work and how that you have a mission like Cassini and it’s really just a platform for a whole bunch of science experiments and each science experiment on that mission is run by a different team, sometimes a different university. So there’s people who work at NASA JPL who are actually helping to make sure the whole spacecraft is operating, that it’s receiving its data, that communications to and from, the telemetry of the spacecraft. But the individual instruments themselves are run by different people and they often will have their own Twitter accounts and their own Facebook pages and they’ll handle their own press releases.
And so, as you say, the main camera imagery on Cassini is just another instrument that’s used for various scientific studies.
Pamela: And I think this got summed up really nicely in terms of just how complicated the politics in this mission are on saturn.jpl.nasa.gov, which is one of the cooler NASA URLs. It says, “The Cassini partnership represents an undertaking whose scope and cost would likely not have been born by a single nation, but is made possible through shared investment and participation. Through the mission about 260 scientists from 17 countries will gain a better understanding of Saturn, its stunning rings, its magnetosphere Titan and other icy moons.”
So you have European leads, you have American leads, you have contractors, you have instrument scientists, you have participating scientists, and all of this is led under project scientist Linda Spilker right now with deputy project scientist Scott Eddington and project science system engineer Nora Elongy. And what I love about this mission is right now two of three top people in the mission are women and you see strong female participation throughout the mission. As you look through all the different instruments there’s a plasma spectrometer that’s a whole bunch of lines; no one ever wants to see those. There’s a cosmic dust analyzer. This allows us to understand the compositions of the bits of debris that can be captured from the rings and as they pass near the atmosphere.
This is amazing science but again, the scientists doing this aren’t producing pretty pictures that appear in the news. There’s an infrared spectrometer again, amazing science. This is what allows us to start seeing the molecular chemistry of the mission. Again, data no one ever wants to look at the pictures in the public.
Pamela: There’s an ion neutral mass and I could keep going. But then when you hit the imaging science subsystem this is one of the smaller teams. The magnetometer is even smaller. But the imaging subsystem is one of the smallest teams and it’s the team that everyone sees everything they’re doing.
Fraser: Yeah. Do you remember when the day the Earth smiled? Do you remember that thing that happened a couple of –?
Fraser: Like a couple of years ago. They were going to recreate that pale blue dot image that Carl Sagan helped organize with the Voyager spacecraft. And so everybody smiled in the general direction of Saturn and then they posted an image of sort of the new picture that was taken by Cassini of Earth from orbiting Saturn. And these are the kinds of things that she has helped organize to sort of help get that word out and really help feed that enthusiasm for space.
Pamela: So that was back on July 19, 2013 and what was amazing about that was for her it was a chance to redo something that she was part of before because she was part of the team that planned the Voyager imaging that didn’t just do Carl Sagan’s pale blue dot, but actually did a portrait of our entire solar system as Voyager looked back on the solar system.
Fraser: So let’s go back into her career and sort of start with – I guess we’ll work on Voyager and sort of what she was involved with there.
Pamela: With her dissertation work at Cal Tech she was focused on looking at the rings of Saturn. It was with Voyager that for the first time we had sufficient detailed imaging to start to see that there were moons inside the rings, the spokes in the rings, and all the other structures that appeared. She was working with dynamacist Peter Goldreich and it was during this work that she started to try and put forward models looking at what are the causes for these spokes? From there she went on to be part of the Voyager imaging team working at the University of Arizona following her successful completion of her dissertation. She was a tenure track professor getting tenure in 1991.
Through her work with the Voyager team she kept looking at rings. She was the lead of the rings working group for Voyager and the rings on the outer two most planets; Uranus and Neptune, are just weird. She was one of the ones that really worked to try and understand why they were weird and the role that moonlets and small moons have in shepherding the, in some cases, incomplete rings and in creating the divisions that we see in these rings.
So that is an amazing combination of using computers when computers were just starting to be able to do complex modeling, to understand complex dynamics of what she was seeing in the imaging data.
Fraser: And so a lot of the stuff that she helped discover at Saturn and I guess some of the outer planets, but really at Saturn what was amazing was then she got selected as the leader of the imaging team on Cassini-Huygens and was then able to verify with much better instruments a lot of the stuff that was very tantalizing, but they weren’t able to really see very close up.
Pamela: And one of the coolest things that they’ve been able to follow-up on is she’d predicted that oscillations inside of Saturn, acoustic oscillations – this is where sound waves traveling through Saturn actually affect its dynamics – that these acoustic waves moving through Saturn actually have an effect on the rings around Saturn. That’s a really precise thing to think about and realize where we know that stars oscillate, we suspected that planets could oscillate, but to carry that through and say, ‘Okay, a sound wave actually creates a density distribution change inside of the star. That should affect gravity. Huh, I wonder if we can see this in the rings.’
There are certain ideas that people come up with that make perfect sense once you articulate them, but the where in your brain do you find that creative spark to come up with that idea is not something that everyone has the ability to do, and this is one of those predictions that really shows that creative spark that is so much a part of being an excellent scientist.
Fraser: It must have been so frustrating to come onto Cassini, to know the capabilities of the spacecraft and then when Cassini got its mission plan I guess changed to take a longer route to reach Saturn using various gravitational assists – I’m trying to remember when it launched but it probably didn’t get to – when did it get to Saturn in sort of 2004?
Pamela: It launched in 1997 and it did a Jupiter flyby in 2000, arrived in 2004 at Saturn. And so here she is, 14 years after being selected to lead the imaging team and she’s finally at Saturn.
Fraser: Finally at Saturn.
Pamela: The thing is though this is the mission that has just kept going and kept producing awesome results all across all of the different missions. During the most recent senior review the team that did the senior review said that Saturn is one of the most well-managed spacecraft going and so where they were originally planned for four years they’ve now done ten and they’re looking at a further extension. We did an entire episode on this that you can go back and listen to, but of the 514 gigabytes that they’ve taken and that’s not a lot of data when you look at missions like solar dynamic orbiter; they do that every single day. With their 514 gigabytes of data they have published well over 3,000 papers and they’ve discovered seven moons, they’ve –
Fraser: Yeah, let’s talk about some of those discoveries. Seven moons, new rings.
Pamela: Yeah. New rings. They’ve confirmed the spokes in the rings, have started to make sense of them. They’ve looked at the storm patterns. They’ve discovered, and this was part of the imaging team that Dr. Porco is part of, that there are vast hydrocarbon seas on Titan. They’ve found snow is perhaps not quite the right word for frozen methane and ethane, but they’ve found frozen formerly liquid stuff falling out of the sky onto the surface of Titan and then in some cases melting or sublimating weather on other worlds. That’s just a great thing to be able to start to study, start to see in detail.
Fraser: They were the first people who saw the cryovolcanism on Enceladus.
Pamela: Yes. I’m kind of – like so many different things happened that it’s hard to know what to hit on highlighting because this is a mission that has spent ten years doing amazing science. And part of the reason that we know about so many different things that it makes me tongue-tied and speechless is because through her work Carolyn Porco hasn’t just been a solid scientist, she’s also been out there as a speaker. A lot of people have the mistaken notion that she’s the principal investigator for the entire Cassini mission because she is one of the most public people on the mission, rather than just being in charge of the most visible part of the mission.
She dedicates a lot of time to going out and communicating what she does; being a consultant on CNN, doing profiles for a variety of different science shows, she’s appeared on things like Stargazing Live and the BBC. And through all of this communication she is helping to continue the legacy of Carl Sagan who was actually one of her mentors, someone that she worked with early in her career. In fact, she was a consultant on Contact, which of course Carl Sagan wrote the book that it’s based on and it said that Carl Sagan told Jodie Foster that in trying to figure out how to portray this character, a character modeled after Jill Tarter who is very much alive, he said, ‘Look at how Carolyn Porco conducts herself and use her as a model for how to act.’ And that’s just kind of odd and awesome.
Fraser: That’s pretty interesting. I didn’t know that he had offered up that as the model for the movie. That’s really cool.
So in addition of course and I guess the latest thing in addition to the work on Cassini-Huygens is now it’s time to spin up for an entirely new mission, a whole new project, which is New Horizons which of course we’ve been reporting on New Horizons for ten years. I actually had a chance – if you look back on my feed on YouTube, about three weeks ago or so, I hosted a hangout with Allen Stern and the Post Docs, I guess that’s their new band, and all of the people who are going to be some of the science team that are working on the New Horizon mission. And of course they’re going to be providing these first close-up pictures of Pluto next year. And by about May or so the images from New Horizons are going to be better than the images from the Hubble.
This is the point where we’ve been stop having to use those same old boring images of Pluto and the artist illustrations.
Pamela: The Hubble images.
Fraser: Yeah, the boring Hubble images of Pluto and the artist illustrations that we’ve been using for a decade, for decades, since I’ve been – like literally for 15 years since I’ve been reporting on this stuff I’ve been using the same five images of Pluto for every single story that we do. So we’re finally going to get new images of Pluto and Dr. Porco is going to be the one who’s going to be helping usher these into our eyeballs.
Pamela: It is a large team and she is part of that team and it’s going to be amazing to see how all of the different science comes out of this because she’s an expert on rings and moons and how all of these different bodies interact, and as we’ve studied Pluto more and more with the Hubble Space Telescope we’ve realized this is a really odd object. It’s one of the larger of the Kuiper Belt objects, it has a moon that orbits such that you really – it’s more of a binary system where the center of mass of Shuron or Cairon, depending on how you pronounce it, and Pluto is outside of both bodies. There are a variety of additional moons and it’s thought that there could be an icy ring.
Talk about having the right person to do the job. This is someone who’s worked systematically on how moons affect the dynamics of systems, on the containment of rings, ringlets at Uranus and Neptune, and now she has one more object to sort out; crazy, awesome, icy dynamics.
Fraser: Right. It’s going to be sort of a different kind of mission though because the thing with Cassini is it’s been orbiting Saturn for, as we said, ten years now and it’s got years still to go, we hope. But with New Horizons it’s going to be this flyby, so all of this work is going to be in this tiny little crunch and the kinds of operations that they’re going to have to do is going to be this really tight coordination. I mean part of the thing is that as they get closer they’re going to be getting better and better resolution images of the environment and they’re going to know if there are other objects that they’re going to try and make observations of.
And then they’ve got this like 13-hour delay or whatever it is – is that what it is? Anyway, multiple hour delay, I’m thinking it’s 13 hours, to reach New Horizons and give it new directions on where to face the camera and what features to point at and if it has to make any kind of trajectory changes if there’s debris or moons or stuff that they weren’t expecting as they get there. So it’s a completely different kind of challenge, right? Just imagine that they’re going to be – when it’s starting to happen and that flyby is happening New Horizons is going so fast they’re going to have to be making these snap decisions to get as much science as they can as it quickly zips past Pluto. So it’s a totally different game. I mean it’s going to be something.
Pamela: It’s Voyager all over again. If you think back to the beginnings of her career it was all about the flybys. And now we have a flyby with much higher tech, or at least as high as it goes with NASA given when it was built, and so you have this new spacecraft that is new technology but the same sort of data run that she saw with her dissertation work at Saturn and her follow-up work at Uranus and Neptune. So sometimes you return back to your origins.
But this time we have her on Twitter and one of the things that I know from my personal experience is everyone assumes that I’m significantly younger than I am because I dye my hair and use social media. I love the implication that social media instantly knocks ten to 15 years off my age and it apparently does the same thing to Carolyn Porco because I made a lot of assumptions about her age based on her appearance and her use of social media and was utterly wrong as I learned in preparing for this show.
So here you have someone that is awesome at social media, did not grow up with a cell phone in her hands, but has figured out how to communicate the excitement of day-to-day discovery and the pain of politics that comes with – well, sometimes you’re more politician than scientist when you lead a collaboration. She’s going to be bringing us all of these new discoveries one paper and one tweet at a time.
Fraser: I’m going to read a quote here, which was an award that she and Babak Tafreshi won back in 2009, the Lennart Nilsson Award. The citation reads, “Carolyn Porco combines the finest techniques of planetary exploration and scientific research with aesthetic finesse and educational talent while her images, which depict the heavenly bodies of the Saturn system with unique precision, serve as tools for the world’s leading experts. They also reveal the beauty of the universe in a manner that is an inspiration to one and all.” I think that’s great.
What’s funny is she had like literally just a couple of days ago she wrote a new post on the Cyclops, this is the Cassini imaging team’s website, about this aspect of the rings which she found quite fascinating. There are these cliffs on the edge of the B-ring which are like 2.5 kilometers high. So normally the whole ring is flat, ten meters thick, but there’s a point in the B-ring where there are these strange cliffs caused by some of the moons I think where they’re like 2.5 kilometers high of this like jumbled cloud and they actually cast these shadows on the rings.
She had sort of mentioned how fascinating this was and someone sent in some art to show what it might look like if it was a spacecraft gliding across the top of the ring. So you can just see this kind of imagination is captivated by the kinds of things that she’s looking at and she’s able to express this fascination at the same time doing the science and going, ‘This stuff is beautiful and this stuff is important scientifically.’ And that is – you couldn’t ask for anything more I think in a scientist than to have those two things. It’s what Carl Sagan had. I think it’s what you have.
Pamela: I try.
Fraser: And I think folks like Phil Plate and a lot of the scientists who are just doing the research but also really helping express that enthusiasm. It’s infections. So kudos to Dr. Carolyn Porco.
Pamela: If you want to see her in action she’s done a pair of TED Talks and I see from folks on Twitter – David McKees is pointing out that she was on the June 29th episode of StarTalk Radio. So you can catch her doing her thing, communicating science in a way that will get you to fall in love with the understanding that she brings to us about the universe.
Fraser: Yes. Go to the Cyclops website and sign up for her email newsletter, which is where you’ll get like missives from her once every month or so. And then you can follow her on Twitter, right? Is it Carolyn Porco on Twitter? Search it up and you can find it. Talk to her directly. At least listen from her.
Pamela: Sounds great.
Fraser: Awesome. Well, thank you very much Pamela and we’ll talk to you next week. I think we’ve wrapped up this series on Modern Women in Astronomy so I think we’re going to go back to Fraser’s crazy ideas about space and astronomy from here on out.
Pamela: Yeah, so we have no clue what our next big idea is going to be so feel free to pipe up and make suggestions and I have Fraser’s awesomely long list of things to choose from as well.
Fraser: Wonderful. All right, thank you very much Pamela and we’ll talk to you next week.
Pamela: Sounds good, Fraser. Talk to you later.
Fraser: Thanks for listening to Astronomy Cast, a non-profit resource provided by Astrosphere New Media Association, Fraser Cain, and Dr. Pamela Gay. You can find show notes and transcripts for every episode at astronomycast.com. You can email us at firstname.lastname@example.org. Tweet us @AstronomyCast, like us on Facebook or circle us on Google+.
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