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In this episode of Brains, Black Holes, and Beyond, Thiago Tarraf Varella sits down with Princeton researcher Dr. Jamey R. Szalay to discuss the science behind Jupiter's auroras. Dr. Szalay also discusses exciting NASA breakthroughs being made by the Jovian Auroral Distributions Experiment (JADE) in learning about Europa, one of Jupiter's moons.
Brains, Black Holes, and Beyond (B Cubed) is a collaborative project between The Daily Princetonian and Princeton Insights. The show releases 3 episodes monthly: one longer episode as part of the Insights partnership, and two shorter episodes independently created by the 'Prince.' This show is produced by Senna Aldoubosh '25 under the 147th Board of the 'Prince.' Insights producers are Crystal Lee, Addie Minerva, and Thiago Tarraf Varella. This show is a reimagined version of the show formerly produced as Princeton Insights: The Highlights under the 145th Board of the 'Prince.'
Please direct pitches and questions to podcast@dailyprincetonian.com, and any corrections to corrections@dailyprincetonian.com.
[Intro music plays]
Thiago: Hi, everyone. My name is Thiago. I'm a graduate student at Princeton University and I'm your host.
Senna: And my name is Senna and I'm a podcast editor at the prince
T: Before beginning the episode we have an exciting announcement to make. We're expanding and rebranding our podcasts to Brains, Black holes and Beyond.
S:It's still going to be a partnership between the Princeton Insights and the daily Princetonian, but soon we should get some episodes with new members from the daily Princetonian and have episodes in other formats.
T: This episode specifically is still derived from the insights, a newsletter written by Princeton undergrads, grad students and postdocs. We write about some of the most exciting research being conducted here at Princeton in the form of short, fun and easy to read reviews from all sorts of fields in science. Feel free to check out our website at insights.princeton.edu
S:Now let's get back to today's episode, because it's going to be really cool.
T:We're going to talk today about Jupiter and its Aurorus. Just like here on Earth, we have the northern lines, and maybe even more exciting, we're talking about it with Dr. Jamey Szeley. Jamey received his bachelor's from James Madison University and his Master's and PhD from the University of Colorado Boulder. During this time he collaborated with NASA in many experiments he has worked with interstellar does with data collected from the moon from Pluto from Jupiter, and found not mistaken he soon should work with data from the Sun. So yeah, that's mind blowing to me. Thank you so much for accepting our invitation Jamy.
Jamey: Yeah, thank you for having me.
T:Awesome. Let me start asking a little bit more about how it all started for you. If we're too bad I would say that young Jamey has always been a fan of the space and maybe watched and read some Carl Sagan and Neil deGrasse Tyson, is that true? How did you get into that field?
J:I was definitely always a fan of space like like many. But it would have to be my my both a combination of very excellent high school teacher for physics that got me interested in academics in general and physics. And then I had a couple of very great professors in college anda family friend that worked in the industry that that opened the door into space science for me. So kind of a lot of little course corrections for many, many people I'm very thankful for along the way.
T:Oh, nice. Could you tell us briefly about what you do and how you ended up here in Princeton?
J: Sure. So I'm a I'm a permanent research scholar here at Princeton. I've been here five years and I research just part of charged particles, neutral particles, pretty much any any kind of particles in space, over a wide variety range of phenomena, as far as as you mentioned, very close to the sun with Parker Solar Probe impacts and the objective processes at the Moon and other airless bodies, all the way out to dusk phenomena past Pluto. And then I'm also very interested in litany of plasma and rural phenomenon at Jupiter. Right now we have the Juno spacecraft in a polar orbit, currently taking all kinds of very interesting revolutionary measurements.
T: Oh That's really cool. Yeah, so we're going to talk more about that. But before we do, so, you mentioned that you're working with Jupiter. A really cool fact they know about Jupiter is that it provided Galileo some of the earliest and maybe most definitive evidence against geocentrism the idea that everything orbits around the Earth, because Galileo found moons orbiting around Jupiter and not the Earth. Maybe I should even record a separate episode just about that. Could you tell us a bit more about Jupiter and its moons?
J:Yes, a Jupiter is really interesting in that it's almost its own solar system in a sense it it was Jupiter was in some aspects of failed star if it would have been something like 100 times bigger, it could have been a star. And it has something like over 70 moons of its itself and a very complex stance and orbital mechanics. Four of them are very much their own worlds. You have their called the Galilean satellites that Io, Europa, Ganymede and Callisto in order of increasing distance. And each one of them is is again, it's its own world, the innermost few may have more water than Earth, and are a potential candidate for habitability. And there are multiple, very large scale missions that are at and planned to go to these various bodies. So it's a target of extreme interest for both NASA and the European Space Agency and the world as a whole scientifically,
T:That's very cool. So that's an example of the impact of astronomy society, which is the potential habitability of the planets. I mentioned before how that research changed our field soft core beliefs in terms of Hala, centrism and geocentrism.Do you have other examples that astronomy research can be important for our society?
J:So habitability is a is a very interesting.Again topic of great interest right now. That's that's certainly of interest to the broader community because it's one of the biggest questions that NASA can seek to answer Are we alone in the universe is there is there other life and Jupiter specifically and Saturn, both of them, they had a paradigm shift in the way we think about it, it used to be that we thought life could potentially only exist in a region where liquid water could exist on the outside of a planetary surface. So Earth is in this region and has to do with the distance you are from the star and the surface temperature. But that that paradigm changed when we realized that you could actually have liquid water oceans underneath icy shells, and there could be enough heat to keep them liquid. And so instead of just looking in this very specific region, all of a sudden, this space of potential habitability really opened up. And it changed how certainly NASA looked at exploration to address these issues. Now we can go to the moons of Jupiter and Saturn and potentially search for this and it's conceivable, even Pluto as cold and far as it is, has a liquid water ocean and maybe a potential source for habitability.
T:Wow, imagine living in Pluto, you've been mentioned in as a bunch. You've been working with data that comes from this NASA missions, not only from Jupiter, but also the moon Pluto. Right? That's fascinating. To what degree is your involvement with this missions? And how does it work in general to have this collaborations with NASA? Is that something that other Princeton undergrads and grad students could get involved with?
J:Yes. So so it's there's a lot of opportunities for involved. And I'm actually working with a student, Wolf in Astro right now. And I worked with another student, Luke, who graduated from physics last year, and I've been doing undergraduate research product projects with me, and they both have been doing really excellent work that has led to publications and peer reviewed journals. And so even at an undergraduate level, it's certainly accessible. And in terms of graduate school, the way the involvement with NASA works, when you're in science, typically, you work on specific projects, those are usually government funded, especially if it's in physics, Space Science. And so for example, when I went to school that was entirely funded by NASA grants, and so that actually was able to put me all the way through grad school. And that's a very common setup. And so if you're interested in working in space science, the nice thing about grad school is it's it's not only is it covered, but you actually have a small stipend that you can live with.
T:Oh, cool. What about you specifically? How are you involved with NASA?
J:So I've been as you mentioned, I've I'm involved in a number of robotic NASA missions, very coarsely, NASA can be split into the human and the robotic side, I'm on the robotic side, where we send robotic spacecraft to various locations to answer specific science goals in a way that's just not possible with with humans. I, One of the exciting future projects is led out of Princeton, actually, there's the mission called AI map, the interstellar mapping and acceleration probe that's led by Professor David McComas, out of Astro. And that's led out of Princeton, and I am co investigator for that. And I work on the one of the 10 instruments, which is called the interstellar dust experiment where material from interstellar space is actually get all the way is able to get all the way into one a unit Earth where the spacecraft will be and we're gonna sense it and in some sense, taste it, see what composition it has, and how it might have evolved and understand our place in the interstellar medium with that.
T: Wow, I'm looking forward to this, it seems really exciting. So you're sending space probes right? For Jupiter, specifically, you sent Juno it left Earth on 2011 and I think arrived there in 2016. What is the process? What happens between the start of the data collection there? And the publication of a paper are for this upcoming project you mentioned about this? What is the timeline for it roughly and how are you involved in it?
J:Yeah, it's it can be a very long road to get anything to space not just because it takes a very long time to get there like you just mentioned with Jupiter for example, Pluto It took almost a decade from launch to get there. And and that those any mission in space that's not earth is. It's pretty tough just communications wise because Pluto, for example, but one way communication of light time was four and a half hours. And that's with speeds that were significantly less than dial up. So it takes a very long time to communicate. The process though, by which you get a spacecraft into space involves a proposal to NASA with a proposal team that takes a considerable effort to put together for example, I map had had dozens of scientists and now we're at the scale of hundreds of people being involved in building the mission, the instruments, that spacecraft one of the insurance is being built also at Princeton, as well as solar wind monitor, or solar wind analyzer.
T:In Princeton, like in the physics department?
J: in the astrophysics astrophysical sciences department, we are our team actually stood up built a lab from scratch and are building a space instrument from scratch, essentially, in the last two years, it's been an incredible effort.
T: Do you collaborate with like the engineering departments?
J: We do have collaborations with the engineering department. And we also have a lot of very talented engineers that work in our group as well and science at all lead this effort. Very good. There's a number of talented people working on this.
T:What about afterwards, I believe that the initial plan had journal collecting data until 2018. Yet now, it seems that this deadline was extended to until 2025. Why do we have this deadlines and what happens to journal after 2025 assuming the mission has not extended again.
J:like there are often the little little bits of dramatic flair that occur with with different instrument missions and space, you know, had an had an issue with its propulsion system, it was originally supposed to pump down into a very short period orbits, but because there was a risk when they discovered after they got to Jupiter, they didn't want to risk firing the thrusters and putting it in, if you will, a wacky orbit that we couldn't do much with. So they elected to stay in these 51 day orbits and to do the same number of orbits we had originally planned, I think it was 33 in the normal, the prime mission 32. That now took three times longer. So already that extended the mission. And what's really neat is is when [you've] that occurred that's already done, the primary mission, the core mission, and when you have an asset in space with a lot of scientific instruments, often NASA will ask the team please put together an idea on what we might do after that. And we did that which you know, and we, a lot of it focused on on moon flybys, we were actually able to fly by Ganymede, we just flew by Europa for the first time in 20 years and over 20 years in September, something I'm actively working on right now. And so we were able to pivot and do more dangerous things so that we couldn't do the radiation environment is extreme Jupiter and we're actually experiencing more and more dose than we ever did before as we pump into these very now close to Jupiter orbits and so it's really exciting. We're gonna hopefully fly by IO, the the moon that's has volcanoes that are constantly spewing material out into space next year, and that's going to be really exciting too.
T:So we should be expecting some space volcano photos in the news next year.
J:in a year and who knows we might fly through the material and be able to also sense it. There's a slew of instruments on on Juno, one of them I work on that was that was again built out of out of this group led by Professor McComas. That is a ion composition analyzer called Jade. And it's able to determine the composition of the material, the charge material that you that hits, this hits the sensors, it's the spacecraft. And there's all kinds of interesting, valuable information, looking for oxygen, for example, or sulfur that's come out of Ohio, and it gives us we've never had that capability and Jupiter in this way. And so it's a really exciting time to be probing all these new regions.
T:You mentioned that some of these probes will be taking photos, I think. But you also mentioned Jade, what are the things that you collected? What is the data from Juno that you're using?
J:So I primarily focus on data from Jade, just the Jovian Auroral Distributions experiment. And that is what's called a time of flight mass spectrometer and looks at plasma, so charged charged particles in a certain speed range that that are detected by this instrument, we can determine their composition by this technique called time of flight mass spectrometry, which in the way that we do it. The basic mechanism is that there's perhaps a bunch of different species of molecules that are charged or atoms and they each have different masses, different weights, for example, hydrogen is very light and oxygen is very heavy. And if you put them all through the same field, the lighter ones go fast, and the heavier ones go slower. And by that speed, we're able to determine what the masses and so it allows us to separate the different compositions of charged particles in Jupiter's very intense charged particle environment. And then learn about the origins and the evolution of of this material. Jupiter, for example, kicks out material into its local space, but actually IO the volcanic Moon is the dominant producer of material in the Jovian surrounding region, we call it a magnetosphere, which is the kind of magnetic area of influence around Jupiter and Jupiter is very unique, and that IO is just spewing out so much material that it clumps up this magnetic environment. And now we can measure the composition of that, for example. And then Europa, which does not spew out material at the same amount, IO was like a ton per second, which is incredible. But Europa probably kicks out a few orders of magnitude less than that, but of water material, oxygen, and molecular hydrogen. And that's something that if we can probe that and understand that we can understand the evolution of its icy surface and how that's evolving. Now it's oxygenated. And a lot of interesting physics we can probe with with the composition of ions there.
T: So, the, when you're saying that you measure the composition of the samples, is it something that is going through the probe going through Juno?
J:we the way that our ensure it works is it's called a top hat electrostatic analyzer and it essentially has a it has a 270 degree field of view, and it has a an opening. And these this material that's charged, if it makes it to the opening, then it has to curve around a path. And we can we can set that the there's a certain way that we can select which particles are able to make it through this curved path. And that's how we look for different speeds. And so ions that make it through the path within the instrument then hit a few different they hit a carbon foil, and they hit some internal workings of the instrument. And that's able to be turned into electrical signals, which we can then analyze and understand what hit us how fast what composition, and so forth.
T:So not only the compensation, but you can also measure the magnetic field you mentioned.
J:So that is done by a different instrument. We have a magnetometer on Juno as well. And that it gives us instantaneous magnetic field measurements. And those are very interesting because charged particles in any environment typically organized themselves by the magnetic field, they kind of get stuck on an if the if you will, if you could imagine those the magnets and you drop some bar filings, the metal filings on it makes that kind of circular shapes around it around the bar magnet that's mimicking in some way, where the particles get trapped in certain ways. And so understanding the magnetic field with the charged particles is really crucial.
T:Nice, I understand that this magnetic field is related somehow to the polar lights? And that Jupiter has one of the biggest or brightest ones? Is it something we can actually see like from normal telescope here from Earth?
J:The it is true that Jupiter's Aurora, which are the emissions that occur due to charged particles hitting its its atmosphere, are the most intense in the solar system. And that's because Jupiter is the most intense in almost every way. It's the fastest spinner, the biggest planet, all these superlatives, it usually wins them all. And so the way over work are, like I mentioned, charged particles get stuck on these field lines. And typically, Jupiter and earth to some extent they have a magnetic field which is oriented so that the poles are roughly in the north and the south. There's some offsets involved, but they're roughly oriented in that way. And so the magnetic field lines construct for us to visualize this, they kind of shoot out from the top and the bottom, almost like hair sticking up from the top and the bottom and the charged particles would get stuck on those lines. And when electrons, for example, are traveling on those lines, and they hit an atmosphere, they hit molecules. They can excite them and that emits light. And so that's what we are able to observe and that's why they're typically in the North and the South because that's where the magnetic field lines come out from that same with same with Earth. Were able to observe that remotely. Hubble has been monitoring it in ultraviolet light, it emits in visible light. The light that we can see with our eyes, but it's very intense and ultraviolet, just a little outside the spectrum that humans can can see. But we have cameras that can look at them and really resolve these measurements. It also emits an infrared cooler, spectrum like heat that also emits. And we can we can observe that with Juno's. Well, we actually have visible ultraviolet and infrared cameras all on on Juno. And what's neat is with Juno for the first time, we fly through these magnetic field structures that hold the particles so we can measure the magnetic field, we can measure the rain that's about to rain down on the atmosphere and understand how that works. Then we can take pictures once it hits the atmosphere and makes all this light emission. And so we can link all these very interesting fundamental processes that all have to occur this complex dance to make Aurora we can measure essentially all of the phenomenon that are producing it at the same time, and location. And so it's been revolutionizing our understanding about how the overall work that Jupiter
T:Wow, you mentioned that this charged particles are somehow responsible for our Auroras and Jupiter has a really strong Aurora. So Jupiter must have a lot of this charged particles. And you mentioned also that a lot of it comes from IO, I think. But in your paper, you're investigating some other sources that are just describing right.
J:So Jupiter's environment is dominated by material that's released from IO, about 90% in number of particles are that are there from IO and IO is is as it's mostly kicking out it releasing sulfur and oxygen. And so that's what we need is the dominant constituent in the magnetosphere, this magnetic environment around Jupiter. But we've also observed by by number about 10% of the charged material is protons charged hydrogen. And that cannot come from Iowa.it's not a it's not a dominant source of that. And so there's been a bit of an open question on where that material came from. There's there's three there are three hypotheses. One of them is the solar wind. So the sun continuously kicks out, material that is released and shot accelerated near the sun and moves radially outward. And that's dominated by protons.
T:That's partly what causes Earth's RRS. Right?
J:So the interaction of that material with the Earth is responsible for much of our Aurora, the earth works a little differently than Jupiter, because it's it's kind of driven more by changes in the solar wind and there's this complex cycle called the Dungey cycle where there's magnetosphere, this magnetic environment kind of snaps closed and open again and that process can generate Aurora, and Jupiter it's more complex because the material from IO has inflated its magnetic environment so much that it's very difficult for the solar wind the material from the sun to actually access inside close to Jupiter, because it's been so inflated. And so even though there's a lot of protons that are hitting that magnetosphere, it's hard for them to get in to the magnetosphere. The other possibility is Europa or the icy moons, they are dominantly water on the outside water is h2o. So there are protons there that could be broken up and then released into the environment. But that one's tough because it's you'd have to break up so much ice and release it as protons that it's just not realistic given the rates that we think that ice is broken up. And the last source was Jupiter. Jupiter could it has hydrogen and helium and many other species in its in its atmosphere. And if you're able to heat that and charge it and kick it out, then that could be a source of protons. And the issue is that we that would be predominantly kicked out near the polar regions, not near the equatorial regions where we visited with spacecraft before and we've never gotten super close to Jupiter. And so Juno was uniquely posed to search for these the potential of Jupiter providing this missing source of material protons to the magnetosphere and we flew by very, very close within a few hundreds of planetary radii from its atmosphere, so it's very, very close. And we were able to systematically observe protons being scooped out from its its ionosphere, its atmosphere, and it was in amounts that are or enough to explain what, what we what we observe.
T:Okay, so you mentioned planetary radii. Is that like the size of the planet?
J:Yeah, so if Jupiter, Jupiter's radius is one, we're flying by, like 1.04, for example. So they are point 04 or 4% of the radius of Jupiter above Jupiter's atmosphere, if you will. So we're skimming. Skimming the atmosphere we fly super close.
T:Is that is there like an analogy? So like, maybe higher than planes last less high than the moon?
J:Higher than planes significantly closer than the moon. Closer than via radii analogy, closer than than many of the satellites that we have orbiting.
T:Cool, yeah. And so what was exactly that you reported it in your paper? You reported it the existence of this protons that are living from Jupiter?
J:Yeah, we were able to for the first time actually directly observed this process, it had been proposed as one of the explanations but in a theoretical capacity and not with with data, because we had never flown to the regions that would be shooting out this material. And we found that when we flew by Jupiter has a main a rural oval, we call it and there's this kind of oval circular pattern of a rural admissions around the north and the south poles. And when we were near those, we found that in addition to all of the aurora particles that are shooting down towards stupid or creating that oval, there was also another phenomenon that's likely related, that's actually able to scoop back up part of its atmosphere, and it's the charged atmosphere, and shoot it away from Jupiter. And so we, statistically, I mean, we flew by, at the time of that paper, I think, 26 times, maybe 30 times. So we flew by Jupiter's atmosphere and saw it essentially every single time, at least in the south. And so it was a systematic phenomena, that's that's occurring at Jupiter that had not been observed previously.
T:Awesome. That's really cool. Congratulations about this findings. That's very exciting. I don't know how much this is related to your projects. But as I was studying about Jupiter, there was something that made me very curious. Why do some people expect that there's a cloud of ice water in Jupiter, even though it was never observed? And what does it cloud of ice water does even mean?
J:So. That's a good question. I don't know how to directly answer that.The existence of water and the ratio of water with respect to other elements is always of interest. There's the clouds structures are also Jupiter's such an intense environment that you can get, you know, here, for example, on Earth, our clouds are water vapor. And that's just due to the composition of our atmosphere and the local pressure and temperature at Jupiter, you can actually get clouds made of all kinds of other interesting combinations of materials. And that's something that we can try to probe remotely. We have some imagers that can probe the depths of those clouds structures and, and try to understand the flow and the composition of that material. And it's just such an extreme environment. It's like a laboratory to study how atmospheric dynamic works and also understand the origins and evolution of Jupiter.
T:Interesting. Okay, so to wrap up and look forward. You mentioned a lot of projects, the Europa volcanoes, the interstellar dust, the Solar Probe. So like, what research projects you're most excited about right now?
J:Very difficult, probably the most difficult question to answer because they're all exciting and in very different ways. I would have to say that right now, there's a number I could maybe give you three short answers. I'm actively working on the probe of fly by data, we just flew by Europa for the first time in over 20 years since the Galileo mission visited it. And for the absolute first time with composition measurements, we've never before been able to determine locally in situ, like right in, in that environment with a spacecraft what the composition is, and, and so we flew by, and we observed all this interesting composition that we had never seen before. And it's all a consequence of the breakup of of water ice and Europa's surface. And it might give us clues as to how much oxygen is building up in the in the ice and, and how much that might be able to oxygenate a liquid water ocean and how a Plasma interacts with an icy surface. There's all kinds of interesting phenomena. So I'm very excited about that. I'm also very excited about the IMAT mission and its suite of 10 instruments. I work mostly on the dust instrument, but it's going to image our heliosphere in a way that we've never been able to do before. Building on the success of the ibex mission, which also images are heliosphere. And so that's that's really promising and exciting. And I'm thrilled to be a part of that. And finally, Parker. Parker Solar Probe is the closest thing we've ever flown to the sun, and it's keeps pumping down. And I'm working on the dust impacts to the spacecraft and probably one of the most intense dusty environments we've ever been to where the spacecraft are constantly getting barraged, and sandblasted. And that helps us understand the evolution of the dipole cloud, which is the largest one of the largest structures in our solar system. It's essentially a dust disc across the entire solar system. And we get to probe the most intense part of it where most of that material roads and shoots away ever to come back. So I would say those three projects and many more.
T:Yeah, that's really exciting. Actually, I have another personal question. What happens with these probes when they are like the commission and the Solar Probe? Are they just? Like, do they go back? Or do they just hang there?
J:It depends on the mission and the location. Things that are around bodies that would not potentially be a candidate for habitability have different requirements. When NASA send spacecraft near to Jupiter, it has to make sure it won't hit Europa, for example, and potentially contaminate it. They're a little critters on the spacecraft, even though we clean it very well. And it's been baked in space, we still don't want to accidentally seed life somewhere else, or contaminate any measurements of future life. So you have to be clever about how you dispose of a spacecraft. And so Juno will not go on forever, eventually, it will have to be the deorbited. They worked on LADEE, for example, at the moon. That was a very short mission, the Lunar Atmosphere and Dust Environment Explorer, and that was at the end of the mission, they basically just crashed it into the moon. It's in this very small orbit and or the moon's gravity is lumpy, and you just let it go. And it's the surface and the moon is not as as much of a risk for life contamination. Parker Solar Probe will hopefully go on for a decade or more was as long as the health and safety of the spacecraft will allow us to continue. There's no getting these back, though. None of them can come back. Those are very the the missions that we send a little piece of the spacecraft back are typically they're called sample return missions. And they're very specifically designed to do that because the energy and the orbital mechanics are very tough for that. So they'll all be out there. The like Pluto, the New Horizons mission that flew by Pluto, get blasted past and it's gonna leave our solar system and never come back, just like the Voyagers in the Pioneer missions.
T:Awesome. Well. Thank you so much. That was really fun talking to learn more about your research, and I hope the listeners were able to learn a lot and that you also that enjoyed the experience.
J:Yeah, thanks for having me.
S: This new episode of B was hosted by Thiago Tarraf Varella, sound engineered by me and produced under 146th managing board of the ‘Prince’. To learn more about Dr. Szeley’s research there is insights article and link in the description from the ‘Prince’ my name is Senna Aldoubosh. Have a great rest of your day.
Transcribed by https://otter.ai