 It's one o'clock on a Monday afternoon, so you must be watching Think Tech Hawaii research in Manoa. I'm your host, Pete McGinnis-Mark, and today our guest is Norbert Schogaffer, who works for the Planetary Science Institute here in Hawaii. Norbert's part of the Dawn spacecraft science team, and Dawn is a spacecraft which has been travelling to the middle part of the solar system beyond the orbit of Mars, and so today we're going to be discussing the Dwarf Planet series. So Norbert, welcome to the show, really excited to hear what you've got to say. Thank you for having me. You're more than welcome, and we're going to be visiting a Dwarf Planet. So can you just tell the viewers what is a Dwarf Planet? We've had people talking about the moon or icy moons of Jupiter. What sort of scale are we talking about? I brought a Dwarf Planet. You've brought a Dwarf Planet. This is a Dwarf Planet here on a table, or a small model of a Dwarf Planet. The real one is about 940 kilometers, a diamond, and it's about 600 miles or so. And we're looking at something, it's a collared, right? So what's the colors involved? So the colors are innovation, red, high, blue, low, and the important or what makes it a Dwarf Planet is that it's very round. So it doesn't have any giant mountains or volcanoes. And so what it implies is that at some stage in Sirius's history, it was soft inside, and the big mountains all sank in and made this object more round. So it's nearly spherical. Yes. Do we have many Dwarf Planets in the solar system? Well, any asteroid belt, which is, you know, within Mars and Jupiter, of course, it's the only one. Now there are more outside the orbit of Neptune, and there is a small number of recognized one. There might be more. We haven't recognized this Dwarf Planet because it's difficult to tell in the shape. So an asteroid wouldn't be that round. It's round like a planet, Sirius is a Dwarf Planet, it's round like a planet. Now I would guess that the sphere is probably the most familiar with Pluto, which is now classified as a Dwarf Planet. It has the same characteristics orbit, different size as Sirius, correct? Yes. So in some ways the Dwarf Planet category was introduced because of Pluto. When it was taken off the planet list, it landed there, it remained the Dwarf Planet category. Because of no end of confusion to all high school students who now have to remember eight planet names is here. And so the Dwarf Planet hasn't cleared its orbit because there's many other objects in the asteroid belt. It's not a planet, but it's also an asteroid because it's surrounded and a roundness indicates it got hot in the inside at some point, unlike an asteroid. And Sirius also has a lot of ice, and so you don't need to melt rock to make it soft inside. You can just melt the ice. Right. But the model you bought this afternoon, it has different colors, so there must be some topographic relief there. And so are we thinking about, say, a kilometer or 10 kilometers height variations across the world? Well, I'm maybe right, eight kilometers or so. Eight kilometers. Okay. All right. Now you're a science team member on the Dwarf spacecraft, so tell me a little bit about what the Dwarf mission was trying to accomplish. When did it fly? Is it still operational? Give me some details. Yeah. So it's a remarkable spacecraft. It has ion propulsion and that allowed it to orbit two different objects. So ion propulsion, you get a, you know, it's sort of weak, but it's continuing. And so you can go, you can reach objects and then leave an object you couldn't do with regular propulsion. So it was at Vesta originally. And Vesta is another asteroid or an asteroid? A large asteroid, a very interesting large asteroid, but it doesn't have eyes and it's also not classified as a Dwarf planet. And Sirius, which was always the main target of the mission was orbit, it's second. And it's the only mission which ever orbited the Dwarf planet. And so we can study its two physics and... Fine. And when did the spacecraft launch or when did it arrive at its target? It arrived at Sirius in March 2015 and it is still there, but no longer at the closest. So it orbited about, you know, one can see that, but it is lowest, it's closest orbit about this height, we call it the Lamo orbit. And now it's further away and we go in a very elliptical orbit soon to get even closer to it. Well, to help the viewers, let's go to the first slide, which I think we'll just basically sunrise, that the first slide should be number one, there we go. And what we're seeing here, looking down from north of the sun in the middle and the arrows point to the orbits of Earth, Mars, Festa and Sirius. So your mission, I say your mission because you're part of the science team, was to go to both Festa and Sirius. Yes, I did. And you've been part of the science team ever since the spacecraft arrived at Sirius, is the sort of thing. And your specialization is in studying what? Ice. I study ice in Sirius, which actually has an interesting rule in Hawaii, interesting history in Hawaii, because there was scientists in Hawaii who predicted it has ice very close to the surface. So on the surface you almost see no ice, there are these bright spots, mostly not ice, but there's lots of ice in the interior. Alright, let's take a look at the second slide, because I think that shows us what the spacecraft's imaging, and for the viewers, what is it we're looking at? It seems as if it's just like our moon with lots of craters. Yes, it's very round, here you see it's very round. Very round. And you also see this bright spotty, okay, the crater, and that's salt, actually, it's not what ice is, it's salt, you know, Kato. Remarkable. And so how would you interpret now that you know that it's nearly spherical, that implies that it's predominantly made of ice? In some way, I mean it implies that it was once soft inside, what scientists call it, the geophysics, it's called differentiating. Now I know you brought a little short video, which NASA has prepared, which will give us a much better understanding of what this world made of ice actually looks like. So if we could run the video, let's, and if, Norbert, you can just talk us over as we start seeing some of the more interesting landforms. So this is prepared by NASA, and all these data are from the Dawn spacecraft, so away you go. Yeah, well here you see right away one of the bright spots again, and lots of craters, it wasn't, you know, it wasn't necessarily expected that it had. The large craters that we're seeing here, they would be how big? About a wahoo size, or bigger, or smaller than? Yeah, about a wahoo size. Okay. So it is a heavily cratered surface, and how this is made by the way is from stair imaging. So there's a camera which looks at a surface at different angles, and then we can make a stereo, you know, we can reconstruct how tall and steep all the mountains are. So this is the OKTA crater again, with this bright spots, that small part of it. Small part of the animations, aren't they? With real data, but obviously. Oh yeah, that's real photos and real topography, and there's a slightly bit of color enhancement, for a reason it would become clear. So at OKTA, there's a little bit of water ice, but it's mostly salt on the surface. This is another crater. Is the topography in this view enhanced, or is this what one would see if you were in a spacecraft in orbit over cities? I think it's not enhanced. So those cliffs are actually quite high. Oh, and this is a famous mountain, Ahuna Mountains, one of the tall mountains, is four and a half kilometer higher, and so here it is far that there must be what we call cryo-volcanism, so a volcanism, but not with lava, not with molten rock, but with molten ice. Yeah, we've had Bridget Contosmith on this show a few weeks ago, and she was talking about cryo-volcanism as well, so this is just another manifestation of water erupting on the surface. Yeah, but there's only one such thing on series, at least currently, there might be more than one. OK. There's another big crater. And these large craters, presumably that implies that the surface is quite old? Yes, and this by the way is Haulani. So there are two craters named after Hawaii names now, Haulani and Loro. There's a feature named, another feature in a solar system, two more features in a solar system with Hawaii names. So yeah, the surface of Ceres is old, but also what it means is that the surface wasn't so soft that its craters haven't relaxed back to flatness. So it sort of indicates a very rigid surface also. Right. And they look quite like craters on the moon with just a few subtle variations, right? So maybe the central mountains are a bit smaller or something? Yeah, there is some, yes, but there's some complexity for central mountains. But you know, on a course picture, it looked like a... All right. Well, we're getting near the mid-show break, Norbert, but I mean clearly you're on the Dawn Science Team for special skills that you have. So when we come back, I'd be really interested here, what exactly you're doing and why you find Ceres particularly interesting. So let me just remind the viewers that you're watching Think Tech Hawaii research in Manila. I'm your host, Pete McGinnis-Marc. And our guest today is Norbert Schalgoffer, who is working with the Planetary Science Institute, and we're learning a lot about the Dwarf Planet series. So we'll be back in about a minute's time. So see you then. This is Think Tech Hawaii, raising public awareness. For every game day, a sign a designated driver. And welcome back to Think Tech Hawaii research in Manila. I'm your host, Pete McGinnis-Marc. And our guest today is Norbert Schalgoffer, who is a scientist at the Planetary Science Institute here in Hawaii. And we're learning a lot about the Dwarf Planet series. Now, Norbert, we got a great overview of what the Dawn spacecraft saw or has been seeing at series. But tell me more about your specialization. What is it that you do and why are you part of the science team? Yeah, I study ice, regular water ice, so to speak. And series has a lot of water ice. And we found a lot of water ice at series, although the asteroid belt is, you know, surfaces of asteroids are usually dry. Series has a lot of ice. And so if you go to the next slide here, we see one of those results. And part of reason I want to show this is not only because I am involved in this work, but also because it is a history in Hawaii. And it was a quarter century ago, there was two scientists in Hawaii. Fraser Finale and James Salveil. And I hope they're watching us. Rumor has it we're still in Hawaii. I know, at least Fraser is still in Hawaii. And they predicted that, you know, there's no ice on the surface of series, but there's ice very close to the surface. And explains the viewers we're seeing what? Yeah, so there's an interesting technique called neutron spectroscopy. So this is nuclear physics, but it really allows us to peek beneath the surface and identify hydrogen, which is a big part of the world. And we're seeing the globe of series here with the equator running through the middle. Yeah, so the polar regions in the blue, there's lots of neosurface water ice. And in the red region here on the equator, there is no water ice near the surface. And what would be the ambient temperature this distance from the sun? Oh, this is quite cold. 150 Kelvin. 150 Kelvin, so minus 120 centigrade, something like that. Yeah, so it's pretty cold. But you're seeing these latitudinal variations. So exactly what it expects from ice, which retreats according to temperature, where it's warm, 150 Kelvin is cold, but still warmer than a poles. And so at the poles, although this object is in vacuum, it has lost very little ice and it's close to the surface. So where are predictions are essentially right? And that's what this map essentially shows. But bottom line though, I often ask our guests, why should we care if there's ice out at the distance of series from the sun? Why is this an important discovery? Well, it's the most direct evidence for lots of water ice in Astro-Belden. So there's water ice in Astro-Belden. And water ice has brought a context in more ways. I mean, on Earth, water is necessary for your whole life. So we are much interested in the origin of Earth's water. We are also interested in the habitability of object in the solar system, which requires water in one or the other. But unlike, say, Europa or Enceladus, which are two of the moons in the Anasolus, there's no liquid water ocean beneath the crust. So series is frozen now, but at some point it was warmer. Okay, and recognizing that there is water ice further out from the sun, does that have any implications for the water we have here on Earth, or is it completely different? Yeah, possibly. I think we now have a few of the Astro-Belden as a reservoir of water ice. Okay, which could have delivered water ice to the early Earth? Early Earth. Okay, so Earth's oceans could have come from the asteroid? Yes, absolutely. Fascinating, fascinating. Well, let's see a little bit more of what you do, because in addition to working with the neutron spectrometer data, you do well at you... Well, there's more ice. There's even more ice on series in interesting places. So there's lots of craters, and the craters near the poles will never see the sunlight, always in shadow. Really? Yes. So they even cold them. And so these little colored dots here are all the craters which never see the sunlight. So as series rotates, we're permanently... So in this image we're seeing the Glober series. The lines obviously are drawn on with computer and where they converge at the top. Is that the North Pole? Yes. And so tell us some more, the little white blue dots, what are they? Yeah, so they never see the sunlight? Never. Never. All right, well, we haven't... How do you know that? Oh, in different ways. One is, there's lots and lots of images and you stack them all. And if no matter what the position of series long it's all... And we did this close to summer solstice. So the sun never gets higher than summer solstice at noon. So we did this for many, many times. And so what's always left dark there is perennial dark, it's dark all year. All right, so presumably the dawn spacecraft has been orbit around series for long enough to see changing seasons? Well, we have seen a change in season, but not all of them, only part of them. But it also was there, it arrived there actually around summer solstice. In the Northern Hemisphere? Summer solstice in the Northern Hemisphere, yeah. Okay, now I've heard that there's potentially ice, say in the polar regions on the Moon or on Mercury. And each of those worlds isn't the orbital inclination or the axis of the spin axis of the world. Well, that implied the series also has a sort of a perpendicular inclination. Yes, yes, so Earth's Moon also has this permanent shadow grader, so does the planet Mercury, and that's because we're not tilted very much. Okay, why isn't series tilted? Well, that might just be a coincidence or it might be a result of its evolution, but I mean there's asteroids with all kinds of orientations. So, and series actually wasn't always that small as it is now, so it varies a bit. And so another reason why series is so important because it teaches us something about this permanent shadow region is everybody wants to mine eyes on the Moon, right? Or wants to study eyes on the Moon. And yet we don't understand why the Earth's Moon has eyes in some places and not in others. And so series is a wonderful example where we can study the same phenomenon. And you can study it in more detail, I think the next slide will show us a little bit more about some of these. All right, so again, talk us through what is it we're looking at here, four individual images of craters. Yes, so this is four snapshots of the same crater and as the… I mean every rotation period of series is nine hours. So every nine hours the Sun sort of, well from that point of view the Sun goes around the crater. So the floor of this crater is always shadowed. That's what this sort of illustrates no matter what time of the day, no matter where the Sun is, the floor never sees sunlight. And this will be high summer in the Northern Hemisphere, so the Sun would never be able to illuminate the floor of the crater. And as we saw in the previous illustration, there are many examples like this. How would you study a crater in greater detail? If you know that it never sees the Sun, are there things that scientists like yourself can do with that observation? Yeah, so it's dark, right? So how do we see what's in this dark crater? That's a great question. It's difficult, but luckily the cameras are sensitive enough. So just from a little bit of scatter light, from a little bit of indirect light, one can get a hint of what's inside this. Why would there be scatter light? There's no atmosphere on series. Well, scatter, I mean scattered from the surface. Reflected, maybe. Reflected, it bounced off crater walls and that sort of thing. Can you see any detail? Well enough of a detail. Enough of detail. Enough of detail. Next slide. The next slide, okay. That's what's in there actually. Basically stretch with images, if you go to one. So on the left on the slide, there's a crater on a regular image where it's dark, but on the right it's just the image stretched. All right, so in the right hand image, we're actually looking into the shadow. Is that correct? Yes, absolutely. Everything else is now over illuminated. And the bright patches, presumably in the middle, is the middle of the crater floor. Yes, so we think this is water ice on the surface now, not beneath the surface, but right on the surface, water ice in some of these premature craters. And this crater is a few kilometers across. Yeah, maybe 10 kilometers. Okay, all right. So it's a reasonable sized one. And I think you've got another set of examples in the next slide. Yeah, so there's another twist to this story that in one of these craters, and that's again on the left, there's an image of a crater. On the middle now, there's a stretched image where you see some bright deposits. But if you stretch it right on the rightmost version, some of this bright stuff actually sticks out into the sunlight, luckily. And then with a spectrometer, which is on board of dawn, one can identify what it consists of. We can't do that when it's shadowed, but one can see it in just a little bit of light. It's water ice. And the spectrum is sort of water ice. So, you know, we really think it's water ice in this permit issue that it reaches. Now as a researcher, just seeing, oh, there's water ice here. That's interesting to the layperson, perhaps. But what kind of research are you still doing to further understand? Are you looking at, say, how much water is in one of these white patches? So are you doing numerical modeling? Or do you? Yes, so one of the big outstanding questions right now is that once in a while, Cira seems to develop an atmosphere, a very thin atmosphere. We call it an exosphere. But it seems to be coming and going. And it's made of water, water molecules. And to find out the origin of this episodic atmosphere, you know, where it comes from. And so that's one of it. And this periodic atmosphere, is that an annual basis? So every decade, every million years? We do not know that. It's been observed with telescopes, you know, telescopes on Earth or in Earth orbit a few times. And other times it's not been observed. So it hasn't happened why the Dawn spacecraft was there. And but we might get lucky and Dawn spacecraft is still being there. And maybe we see form again. So at this point, we don't have enough data to say how often it's there and why it's there. But it's been observed in the last 30 or 40 years. So it's an ongoing process. It's not something which is, you know, a billion years ago or something like that. Yes. How did you get into this line of work? It's kind of a specialized field, isn't it? There can't be many people working on ice on dwarf planets. Yeah. Well, all research is specialized, right? Otherwise, you know, it's just a very complex and big world, right? And so, I mean, I came to Hawaii to study ice, right? That doesn't make sense to me, but there you are, yes? So I study ice at many places where one might not expect it to be, including places in Hawaii, including places on the moon, Mars, and no series. So there is some systematic, you know, view to what I do. Well, I know a little bit about you, and you're not really a glaciologist, someone who would study ice in the same way we would investigate on Earth. So are you a physicist? I'm a physicist. You're a physicist. I'm a physicist, and I use physics to explain the real world, so to speak, and under, you know, extreme conditions. And so I think this is a wonderful application of physics. So any young viewer who's watching who says, this is a really fascinating topic, how would she actually start progressing towards doing the kinds of studies you're involved in? It sounds as if do science at high school math. Is there a lot of mathematics in there? Well, if you're into physics, you have to be good at solving physics problems. So solve physics problems, and if you're really good at solving physics problems, every school wants to have you. But it's remarkable. Every university wants to have you. Remarkable. Coming to Hawaii to study ice. I know you work in various venues on the Big Island, which is a very interesting place to find frozen ground and that sort of thing. Just briefly though, the Dawn spacecraft is still collecting data? Yes, it's still collecting data, but it's further out now when it was on its closest orbit. And so in that sense, the main mission of Dawn, is the most interesting part of the mission is over. I mean, the low orbit part has ended. But you're still collecting data, and as I mentioned, we are going to now put in an elliptical orbit and get very close to the surface when we have been before. So we get even better images and better neutron data. And how long do you think the space craft will stay alive? We know Cassini just dived into Saturn, for example. Space craft missions, and for two reasons, either technical reasons in our case, it will run out of hydrogen, which is... So it's not in propulsion, but it also has hydrogen for parts of its tasks, and after that it can't be stabilized anymore. Or we run out of budget. So let's hope it will end, but technically it's not for budget reasons. Well, unfortunately, this particular show is running out of time, Norbert. So I'm going to thank you for being a fascinating guest today. And let me just remind the viewers, we are watching ThinkTech Hawaii, Research in Mana. I've been your host, Pete McGinnis-Mark, and our guest today has been Norbert Schogoffer, who is a researcher with the Planetary Science Institute here in Hawaii. So thanks for watching and join us again next week for another Research in Mana. Goodbye for now.