 This is Think Tech Hawaii. Community Matters here. It's one o'clock on a Monday afternoon, so you must be watching Think Tech Hawaii, Research in Mana'a. I'm your host, Pete McGinnis-Marc, and I guess today is Brigitte Smith-Conter, who is an Associate Professor in the Geology and Geophysics Department at UH Mana'a. And today's topic is a really fascinating one, Brigitte. We're going to be looking in the outer part of the solar system. We're going to be looking at two worlds where potentially there might be life. So before we get started, you're a geologist. Geophysicist? Yes. A geophysicist who studies the interior of planetary objects. That's right. That's correct. And you're looking in the outer part of the solar system. So to get the audience up to speed with the outer solar system, let's take a look at the first slide. And we're going to be talking about two small moons, or two relatively small moons. Here we see them, and we're looking at Europa on the left, which is a moon of Jupiter. That's right. And a little tiny moon called Enceladus of Saturn. And we don't really have a scale here, but I guess Europa's about the same size as our own Earth's moon. That's right. It's a little bit smaller than Earth's moon. About 3,000 kilometers in diameter. And Enceladus is much smaller in size. Way, way smaller. That's right. Enceladus' diameter from end to end is about 500 kilometers. So we're talking 500 compared to 3,000 kilometers in size for these small moons in general. Okay. And we've had on the show in previous episodes, we've had people talking about our own moon. Where in the solar system are we going to be exploring? All right. So how far away from the sun are we? Very far distances. We are several distances of Earth to the sun is about 15 million kilometers away. And Jupiter and Saturn, where these moons reside, are several times that distance. Europa happens to orbit Jupiter. And Saturn, excuse me, Enceladus happens to orbit Saturn. Okay. And so Enceladus is even further distance than Europa is because Saturn is at a further distance from the sun than Jupiter is. And I noticed that both of those moons that we saw in that previous slide, they're this bright color. Are they made of rock or something else? They are made of ice. They are made of ice. And they are very bright because they're very reflective. The icy surfaces that both of these moons are surfaced by allow the sun's light or energy from Jupiter or Saturn to reflect off of their surface. If it was a dark moon, you wouldn't see a very reflective surface at all. These happen to be very bright, icy, sometimes fresh ice that makes some of the most reflective properties on these moons. And so Europa, being an icy world about the same size as our own moon, could have an interesting history. Are they about the same age as our moon? You know, we think that actually these moon surfaces are geologically young because they show no evidence for old cratered regions like our moon, who has our moon has sat around for a few billion years and been hit by asteroids that leave a mark and haven't been resurfaced since. Whereas Enceladus and Europa seem to have a much smoother, glossier look to them with very few surface craters that indicates that these moons could be very geologically young, if not active today, presently forming. And I guess because they've got four young surfaces, that might tell us something about what's going on inside these worlds, which make them really fascinating. That's all we've got. We have observations of the surface and some data about the subsurface. And after that, we have to apply some basic physics to identify or at least infer what might be taking place inside. And as a geophysicist, you're interested not only in the surface, but what's underneath? What's driving the underneath? Yeah. We have to use surface images and surface data taken from spectrometers to allow us to figure out what kind of molecules and chemicals are at the surface. But the images tell us what the things look like. And then we compare everything to what we know here on Earth. And that's where it gets fun, I guess you could say. Well, without more ado, let's take a more detailed look in the second slide. I think we're going to see one of these two worlds. Tocas third, we're seeing what may be the moon on the right hand side, but a couple of other images down at the bottom is that crescent shape thing. Okay. So, yeah, we're seeing this is a slide of the surface of Enceladus on the right. You'll see it's very white and bright. And at the bottom corner of the moon, and kind of this is an image taken from the south pole, you can see four would look like bluish streaks. These are actually fractures or analogy to faults here on Earth. And these are icy fractures and the south pole of Enceladus. And from these fractures that we think act like faults, we have noticed through observations taken from a very special spacecraft called the Cassini spacecraft. There are these icy plumes or geysers that are emanating from the south pole almost directly coincident with the actual locations of the fractures themselves. These plumes tend to look like they're from isolated spots, but we actually think from different viewing angles they're like curtains of plumes coming up and emanating from the faults. And I would guess that perhaps we're looking the plumes would be like old faithful. Exactly. Except are they the same size? These plumes actually because there's very little gravity on Enceladus, these plumes can rise to several kilometers high up into the atmosphere of Enceladus, whereas old faithful is bound by gravity on Earth, which tugs down the water that is emitted from Old Faithful only after a couple of hundreds of feet I believe. So these plumes actually, some parts of the plumes are light enough that they escape from Enceladus and they actually have been identified in one of the rings of Saturn. We think that these jets are actually forming the molecules and particles that form the E-ring, the outermost diffusive ring of Saturn. The ring is there because of Enceladus' jet. So if you're walking through a telescope with Saturn here on Earth and you see part of the Saturn's wings you're actually seeing something. Something. That's right. But let me quiz you. You said earlier that Enceladus and Europa are very young, but I got the impression that only the southern part of that image that we were looking at was devoid of craters. So you're right. There are craters on Enceladus' surface, whereas some of that terrain would be considered older, but this younger part in the South Polar region is substantially void of craters. Yeah, let's go back to that same slide and just show the viewers again that we're actually looking at a whole variety, right? So the top with lots of holes or craters. That's right. That's an older terrain. Still has been resurfaced enough that it's not as old as Earth's moon. It's substantially younger, but the region in the South Pole where these four structures of faults are, they have very little craters, if any, and very young surface region, we believe, based on the images. And so the area where we've got this sort of this temperature of the tiger stripes, those blue lines, that must be very young because there's no craters. That's right. That's right. And I should point out that the blue lines are actually taken with an infrared camera. So it's not true color. It's sort of a false color. And the blue shows up as blue if the ice crystals are slightly larger and potentially a little bit warmer. And so the other map that we're seeing on this slide is a map of heat that was acquired at the South Pole. Usually the South Pole of Enceladus is very, what the entire surface is very cold, something like 200 degrees Celsius, minus 200 degrees Celsius. That's about minus 300 and something degrees Fahrenheit. Very, very, very cold. But those particular heat structures associated with the faults are 100 degrees in Celsius cooler or warmer. And so we think that that heat that's emanating right at those structures is being absorbed from somewhere deeper beneath the South Pole region. The source of it is still in a debate. It could be some sort of water body that could be fault-like structures below that are shearing and grinding away. And how do we know it's water or water ice? I mean, we've never bought anything back from. We have not. No, hopefully someday we will. The best we've done so far with the Cassini spacecraft is we've taken the actual spacecraft down for a peek. It swooped in and sampled the jets. And the results that came back were that there was water vapor in the jets. There was methane. There was carbon dioxide and other types of some organic compounds as well, and some dust particles that allow us to then phone home back to Earth and sort out what all this chemistry is about. So this Cassini spacecraft has actually flown through the close? It has. We have a slide a little bit later. Is that the next one? No, it's probably the one after the next one. Let's take a look if we can go to slides ahead. That's how we get the heat, I guess. There we go. So the most recent fly-by of the plumes or one of the most recent ones was a couple of years ago in 2015 where the Cassini spacecraft dove down as shallowly as it has ever to about 40 kilometers above the surface. And the red arrow we're seeing here is the part of the swooping spacecraft. That's right. And it was able to collect with different instruments on board the spacecraft the material in the plumes, actually flying through the plumes and sampling them and trying to sort out what kind of chemicals are inside those plumes. Fascinating. And so I'm seeing at the bottom, presumably, that's a cutaway diagram of the Moon itself. And it's, say, icy crust hydrothermal vents, which, presumably, are hot. That's right. And they're liquid. So what's causing this heat? I mean, in such a small world, one would have expected it to have cooled down over the age of the solar system. That's right. So it's an icy world, but we suspect from a lot of good scientific data that it's also a water world. Or at least there is some big pockets of water, if not a global ocean underneath its icy crust. We don't know exactly how thick the icy crust is on Enceladus, but we think that it's about maybe 20 kilometers, and below that is liquid water, an ocean just like Earth's ocean. And where it came from, we believe, is from heating from inside the Moon because the Moon gets tugged and pulled as it goes around Saturn. And it orbits Saturn once every day and a half or so. And if we back up to the previous slide, I think you've got a little cartoon. Here we go. Yeah. So there's a graphic that shows Saturn and then this wobbly body orbiting Saturn. And over its course of its orbit around Saturn, Enceladus encounters a closer position to Saturn and then moves along on its orbit and is further away from Saturn. And when it's the closest to Saturn, it experiences some very high gravitational forces. Saturn is just pulling and tugging on it. And then it moves away from Saturn, the gravity is lessened. And so because of the difference in gravity and pulling and tugging, Enceladus gets pulled and tugged inside. And that tidal heating causes heat inside to actually melt the ice, that would be ice, into an ocean body. This happens on several different moons of Jupiter and Saturn and potentially Neptune and Uranus. But particularly for these bodies, we think that the ocean layer may be quite considerable. That may allow for these surface geologic activities to be seen. I think in a previous show, we actually had a discussion of the active volcanoes on the moon of Jupiter called Io. Is this exactly the same sort of thing? Because there aren't that big moons further out of Saturn. That's right. This is the same tidal flexing and forcing idea, except that Io is so close to Jupiter that experiences extreme heating. And Io is a rocky body and probably got so warm that it couldn't hang on to its water. But Europa is much further out from Jupiter, sorry from Jupiter. And so or Enceladus is from Saturn, sorry about that. And so the further out you are from your parent planet that you're orbiting, the less of a gravitational tug you're feeling. And so Enceladus may have had ice and water because it is at a nice location where it can actually maintain those conditions. It may have not always been that way in the past, and perhaps it may not have a stable orbit now. So this is one example. We're coming up to the break in the show right now, Brigitte. But I know you've got another one. We'll take a look at a second moon in the solar system, which has almost the same set of circumstances. That's right. That's right. I stumbled through those words, but I'll read the words right away. Europa will just suddenly appear on the screen. But we're about due to take a break. So let me just remind our viewers, you are watching Think Tech Hawaii research in Manoa. I'm your host, Pete McGinnis-Marc. And our guest today is Brigitte Smith-Conter, who is an associate professor in the geology and geophysics department at UH Manoa. And we'll be back right soon. Bye. For every game day, assign a designated driver to Think Tech Hawaii's research in Manoa. I'm your host, Pete McGinnis-Marc. And our guest today is Brigitte Smith-Conter, who is an associate professor in the geology and geophysics department at UH Manoa. And before we leave the Saturn system, we really have got to talk about the Cassini spacecraft, which provided all of those wonderful data, right? That's right. So what do we need to tell the audience? An important event is coming up in the lifetime, a lifespan of the Cassini spacecraft. This was originally arrived at the Saturn system in 2004. And we are experiencing the last few weeks of its lifetime. It's running out of fuel. The spacecraft has surpassed even the milestones we thought it would in the last 11, 12 years of observation. And on September 15, 2017, the NASA and those that help orient the satellite will purposefully dive it into Saturn's atmosphere in order to prevent any type of contamination or crash landing into a moon. So in about two to three weeks, our viewers may actually start hearing press releases from NASA or the European Space Agency about saying goodbye to the spacecraft. It's a bittersweet time, yes. And we also have had a previous show on the methane lakes of Titan, and it's the same spacecraft. The same spacecraft. It did a lot of work. Yeah, a lot of amazing discoveries. Okay, well, we'll keep our ears tuned for that. But let's move on to the other world, which you're going to tell us about. This is Europa. We saw it briefly before the break. So if we can bring back, this looks quite different. I mean, apart from the fact that the lines on it are orange as opposed to blue. Yes. Tell us a bit about Europa. So Europa is our other water world that has excited scientists for a couple of decades now. This is a not pure ice surface. It's mixed with a lot of these red streaks, as you mentioned, Pete. And the red streaks, or linea, they're called, are perhaps evidence of faults and plate like motion of shifting of ice at the icy surface of Europa, and perhaps an expression of what could be happening down below in terms of moving water around that translates to icebergs shifting around the surface. The red, though, we believe, could be evidence for some sort of deposit of salt. I think we have a close-up of a few of these red lines. Let's go to the next slide. Ah, here we go. So this is not true color, though. This is, yeah, a false color. False color. That's right. I don't know what band of imagery this is. One wouldn't see it with one's eyes. Yeah, the reddish brings out what we think is perhaps magnesium sulfate in the icy crust, and it's a mixture of different chemicals. But we believe it could be the icy surface is tapping into chemical compounds in the ocean below that are being brought up to the surface at these fault-like structures, and perhaps recirculated throughout, sort of like plate tectonics on Earth. We see those banded fractures that are labeled there are analogous to what could be spreading centers at Earth's ridge system in the bottom of the oceans. And these bands can be 20 kilometers wide, so a significant portion of Honolulu could sit in one of these bands. Now, you've mentioned water a number of times. Yes. Is that important knowing that there's liquid water somewhere? It is absolutely relevant, especially when we're studying these bodies, because water is a source of life here on Earth, and wherever there's life, there's water, or wherever there's water, there's life, I should say, on Earth. And so that tends, takes us to the idea of, well, if there's water on these other bodies in the far distant cold regions of the solar system, could life, primitive life, microorganism type of life, actually have once grown there, or be trying to develop now. And so we need to know a lot more about these two moons in order to gain a sense of if the conditions for life are right. But there are some four functional things you need for life to exist on a moon and on Earth. One is you need water and check both of these moons. We believe have water bodies. A second thing is you need an energy source. We can talk about that in a minute if we'd like. A third is that we need some sort of organic chemistry to take place, something with carbon. And then the fourth is a stable environment. And we believe Europa and possibly Enceladus have three out of those four. The only question is whether or not these two moons have a stable environment. If they have been stably orbiting their parent planet long enough to host life and keep it there and maintain it. And that's a question to still sort out. But we know there's water beneath both of these bodies. We just need to understand how thick it is and what they're... And the energy source we already saw with Enceladus is this gravitational energy. That's right. We believe that there is an energy source that allows for the heating, but we also think that there could be this hydrothermal process that mixes the water bodies with the rocks at the bottom of the seafloor that stirs up this mineral-rich water that may be an environment that very primitive and exotic organisms can actually thrive and develop. And that's where we find some of the most exotic organisms in Earth's oceans is the bottom of the seafloor from these heated vents coming up from Earth's mantle or Earth's upper crust. And so the conditions for that type of process taking place in Europa and Enceladus are pretty good as well. We're seeing evidence at the surface. So a $64,000 question. Why would we care? If there was life beyond the Earth, do you want to go there? Sure. Some of it is just inquisition. And we want to know about how Earth developed and how life developed on Earth, but don't we want to know beyond Earth and what the conditions are beyond our own home planet? And if life could persist not just here, and how special are we? Is Earth the one and only in the universe? Is there life on other bodies? And if there is, that's an indication that there could be life on other planets at other stars, and you can go on from there. But there's just so much curiosity out there that makes us want to think and believe that there could be all the conditions right for life. We just have to go and find it. So if it is important to discover life beyond Earth, what's NASA doing about it? I believe you're part of a team or... Getting there, yes. I'm on a pseudo team, that's right. So there is a mission being planned by NASA called the Europa Clipper, and this has been a mission being planned for a long time, but the funds from Congress have now been allocated and they're working on the planning part of this mission. But it's to send a Europa spacecraft, or a spacecraft to Europa, hopefully launched in the early 2020s. The spacecraft will have about nine instruments on top of it or inside of it that will be able to observe the different parts of Europa. This will go into orbit around Jupiter and with flybys past Europa. Jupiter itself has such a harsh and radiation environment that if you were to send missions directly to Europa, the instrument would not be living very long. So there'll be flybys of Europa in order to get out of that harsh environment as quickly as possible, and then there is the plan to send a lander to the surface of Europa and hopefully do some nice geophysical tests. So I'm a sci-fi fan. I watch the science fiction movie Europa Report. Is that the kind of thing you're thinking of? Or is it more Arthur C Clarke 2010? So they're hoping to land safely and protect it with much technology as we can. A lander that would do some basic geophysical observations. And the geophysics would be... If you had a seismometer on top of the lander, you would be able to test what types of seismic waves would be propagating through the icy crust, perhaps from faults moving, to see how thick the ice crust is as well. They can do surface measurements where they can actually dig up material and onboard analyze it to see what the ice is made out of. These are all high-risk endeavors though, because a lander is not safe on the surface of Europa because of the harsh radiation. But you say by the mid-2020s the spacecraft might fly, so are they starting to build it now? They're in the works for planning it and I would assume that the construction will be underway soon. Some of these proposal teams of getting these instruments put together are still being built in NASA's delegating responsibility. I know one of the former graduate students from UH is actually building one of the spectrometers for this machine. Which leads me into... And this is a esoteric kind of topic to be working in. So how did you get here, not to the studio, but how did you get to the point in your academic career that you're studying these worlds in a far solar system? And how might some junior undergraduate, if she wanted to follow your full path? How did you get? I hopscotched around quite honestly. I started out as an astronomy and physics major and received my undergraduate degree in that field and then I jumped ship and went over to study geophysics on earth, studying terrestrial bodies, because I was interested in how faults work and I didn't get enough of that in the astronomy field and so I was lucky enough to move along through my graduate career studying the San Andreas Fault and figuring out how fault systems move and deform and how we can observe that. And then I just ran into an opportunity to apply these physical methods on earth to study the icy environment of Enceladus as a postdoctoral scientist and it all just worked out together. I used the physics on earth to study the physics on Enceladus. So as we've heard in many other shows it's having a science or a STEM background where there's science or technology, engineering or math. That's right and you know taking the necessary classes to support that but also taking some of the computer coding courses nowadays and keeping up because all this is done on computers and all this is done with models and being able to understand how computers can help us understand the math and the physics is a big tool. And I know that you teach a 100 level undergraduate course at UH this semester. That's right. Is there a lot of enthusiasm for this sort of thing? I think so. No one's fallen asleep in class yet. I always get students that come by after class and ask me a question about you know whatever material we've been talking about but they're particularly interested in these really up-to-date missions like the Cassini mission, perhaps like the Yoruba lander that will be arriving soon. It's happening now. This isn't 20 years ago in your textbook that you're reading. Wonderful career path for this sort of student, yes and maybe by the time they're doing their post-doctoral degrees there'll be all these data back from the Europe. That's right, that's right, that's right. Terrific. Well I'm afraid we've got to the end of the show but hopefully you can come back and tell us more about earthquakes and the Cassini mission. Then we just remind the viewers you have been watching Think Tech Hawaii Research in Manoa. I've been your host Pete McGinnis-Mark and our guest today has been Smith Conta who is an associate professor in the geology and geophysics department at UH Manoa. So hopefully you'll be able to join us again in two weeks time after Labor Day when we'll have another interesting guest. So thanks for watching and see you again soon. Bye.