 Okay, we're back. We're live. It's Monday, one o'clock, rockin'. You know what that means. You know what that means. That's research in Minoa. We'll be talking to people who are doing research at the School of Ocean Earth Science and Technology at UH Minoa, and more specifically in the Hawai'i Institute of Geophysics and Planetology, which we'd love to talk to them because they think big. Sarah Faggots joins us today. She's a researcher for HIGP. Thank you for coming down. Absolutely. It's great to be back. And our title today is Icy Volcanism on Jupiter's moon Europa. That's right. In case you were wondering, and Europa is named after Europe. Well, I think it's named after Zeus's lover or something like that. The original before you. Okay, and you're researching, my goodness, you're researching this to find out about this Icy. What is Icy Volcanism? What is that? Okay, the technical term that's been used in the literature is cryovolcanism. And Jupiter's moon Europa has a lot of water on it, most of which is frozen at the surface. So it presents an icy surface. And similar to the way in which we have rock and magma producing volcanoes on Earth, on Europa we think we have ice as our surface crust and then eruptions of water through that ice onto the surface to produce this so-called icy volcanism or cryovolcanism. How do you have an eruption of water? I mean that'd be a whole different composition than Earth, right? Yeah, it's kind of difficult because actually on Earth magma is less dense than rock, so it wants to rise up through the rock. But on Europa water is is more dense than ice, so it wants to stay where it is under the ice. So we think we have to pressurize the water somehow to get it to the surface to produce these eruptions. Heat maybe? Heat or if part of the ice starts to freeze it pressurizes the interior or maybe if you've got gases dissolved within the water it can drive it up through a bubbly type of eruption. So it's a big question mark. We don't really know how it operates, but we do see on the surface these really enigmatic features that suggests that fluids have come up from underneath the surface ice. It's so interesting because we know, and we know that there are certain things that are constant in our solar system and maybe the whole universe, and that is one is the periodic table of elements is the same on every planet. It's not that far away that it's different, it's the same. The other thing is that the laws of physics, am I right about this, are the same in our universe, in our solar system anyway. That's what we believe. And then at the same time though you're saying that the process that happens on Europa is different than anything we see here on Earth. Yes, we think so. We think there's very specific conditions on the Europa that induce this kind of volcanism that we don't see on Earth. And it's partly immune and partly a fact that Jupiter is, it's two planets out from us, so it's in a quarter part of the solar system. The moons there experience much different conditions. The surface temperature of Europa is something like minus 240 Fahrenheit. So the ice behaves like rock, the water behaves like magma, that's what we think. How interesting. How do you know stuff about Europa? I mean we haven't been there, right? Well, we've sent spacecraft. The Pioneer spacecraft very early on, then the Voyager spacecraft in the 1970s, flew by the Jupiter system and then on out to the edge of the solar system and beyond. And then in the 1990s we sent the Galileo spacecraft and Galileo was the first spacecraft to go into orbit around Jupiter. And every so often when the orbit was favorable it would fly past Europa and snap a bunch of photos and take other data and it would fly past the other satellites as well. And so we got the first really consistent data back from that mission and several things, or several data sets, told us really intriguing things about Europa. We saw the surface was covered in these cracks and these blotches, the magnetic field that we measured at Europa suggested that there was actually a conducting water layer there. We didn't know there was an ocean of Europa until the Galileo space. Good spectral imaging, you can see that it's water. Yes, there was a spectrometer on board and the signature from the surface is overwhelmingly water ice but we do see these non-ice compositions there as well, salts, sulfur, things like that that are associated with the sort of splotchy dark patches on the surface. We had Jeff Taylor and Linda Martel a couple weeks ago and talked about the creation of moons, I guess, moons of, I forget what planet it was, but it was moons. Do we have any idea about how Europa was formed originally? Would you come off Jupiter or what? Similar processes, the solar system is forming as Jupiter is forming this leftover debris in the orbit around Jupiter and Jupiter has like something like 67 moons, most of which are smaller than 10 miles across so you know little residual chunks of rock floating around that didn't get either, they didn't fall into Jupiter or they didn't get sort of amalgamated onto the other satellites so it's leftover debris from the planetary and solar system formation that produced these these moons, yeah. If I was a piece of space debris I would rather be associated with a large piece of space debris in a moon rather than just floating around myself, it's just my and there still is some residual debris up there, Jupiter has a ring system just in the same way that Saturn does but it's not as well developed as Saturn's ring system but there are rings of little chunks of rock and dust floating around in space there that never got sort of sucked up into the bigger bodies. Fascinating. Is this a special planet for you, Jupiter and Europa? Yes, when I was a postdoc I was working for Rangreela, Greeley at Arizona State and he was one of the co-eyes on the imaging instrument on board Galileo so that's when I first got my first exposure to these icy moons of Jupiter and our job was to to look at the brand new fresh images coming back being beamed back down to Earth and look at them and just figure out what it was we were looking at. Like being a detective. Yeah so it was a very exciting time, we were frequently completely confused by what we were looking at, these were things that hadn't been seen before so yeah that's why it's special for me and so I spent several years working on Europa during the Galileo mission and I've always sort of had a fondness for understanding these exotic forms of volcanism and I'm just now again starting to think more about cryovolcanism on Europa again. Yeah let's look at your slideshow we have several slides we're going to show them now and you can tell us what they are. Okay this is sort of the family portrait of the Galilean moons of Jupiter there are four large moons of Jupiter you can see that Europa is probably it's the smallest of these four although as I mentioned there are lots of others and this graphic shows the interior structure of Europa it's got an ice shell that's some probably tens of kilometers thick and then a big layer of liquid water underneath it surrounding a rocky mantle and an iron sulfide core and on the right hand side of this graphic you can see how interesting the geology of this surface is it's very fractured there's lots of mottled spots there are very very few impact craters from meteorites heading the surface and that tells us that the surface is very young less than a hundred million years which is a geological blink of an eye compared to the 4.6 billion year age of the solar system so that's what suggested to us this very youthful surface suggested that there must be active geology resurfacing recovering this surface and so the puzzle was the question was what is this active geology. Yeah but you had this dissected version a photo chart drawing of the moon yeah um how do you know what's inside how do you know that the water layers that deep how do you know there's an iron core how do you know that it's drilling what no no there's there's several lines of evidence first of all we can tell by its orbital motion what kind of mass the body has and that and we we know what size it is as well so from that we can figure out a bulk density and that bulk density is closer to that of rock than it is of other materials so we know there's a large amount of rock in there and then when we send spacecraft up there the instruments they have on board and the trajectories around the bodies tell us for example gravity and magnetics tell us about the the structure of the interior the magnetics tells us that there's liquid water there and it must be a certain thickness to to be able to conduct the electricity that we was part of the detective work yeah yeah so it's a number of different lines of evidence but that's our our current sort of best understanding of the the structure it's it's too heavy it's too dense to be just ice so we know there's rock and metal in there as well it's so it's so interesting it's Sherlock Holmes it really is I can imagine how exciting it is to to have confirmation of one you know theoretical fact that you learn from one source and then you have another source and it confirms the first conclusion right and now you know a little better a little more confidence about what's up there yeah you just add each little piece of evidence up over time and then you can start to be more confident in your in your research great that's exciting mentally exciting I think we're gonna take a short break Sarah Sarah Fagan she's a researcher at HIGP the Hawaii Institute of Geophysics and Planetology they like coming out and telling us what they're doing we really appreciate that we'll take a minute and we'll be right back hi I'm Ethan Allen host of likeable science on Think Tech Hawaii I hope you'll join me every Friday at 2 p.m. to discover what is likeable about science we bring on scientists of all astronomers physicists chemists biologists ecologists and they talk about their work and more importantly they talk about why you should talk about their work why you should think about their work why you should like their work I help them bring out why their work is understandable why it's meaningful why people should care about it why people should support science we have a good time we talk about current events of interest we talk about historical events sometimes we dig deep into their research why they do what the joys and delights and frustrations of their work are and in all we show a real world of science a real world of likeable science I hope you'll join us every Friday at 2 p.m. one we're back Sarah Fagan's researcher at HIGP in the school of ocean earth science and technology talking about an icy volcanism on Jupiter's moon Europa wow we're way out there on this one so let's go back to the slideshow what have you got okay okay so this is a shot of some of the surface features of Europa Europa is about 2000 miles across a little bit smaller than our own moon but looks very very different from our own moon as you can see there's these these linear months this is a false color image I should say which is enhanced to show the compositional differences Europa as I mentioned is predominantly water ice but these darker reddish colored areas areas where we see different compositions salts some sulfur compounds things like that so it's a very very young very tortured surface the graphics on the right at the top show some zoomed in areas these these pits and spots we see these these we started off calling them freckles during the Galileo freckles they look like freckles they do so we actually ended up they were called lenticule which is a more okay official sounding name but if you zoom in on those the three little panels below the top right show what these things look like very close quarters they're about you know three miles four miles five miles across and they look like material has been oozed up and pushed out onto the surface and you can see the background ridges it's a very tectonically active place as well the bottom on the right shows a zoomed in area of of the south the southern hemisphere of Europa and we can see these dark low bait muddy looking features which before we had the very high resolution data were thought to be flows of material over the surface but when we look closely we see it's actually disruptions of the surface chaos that the surface has broken up and and been moved around so-called chaos terrain and we think there's been some liquids released at the margins the very dark margins of these features as well if I were there if I wouldn't not that I would be but if I could be and would be what would what would it be like is that is that going to be some kind of different color of rock is it going to be some kind of lava kind of thing it would be it would be a subtle color change as I mentioned those are enhanced color images so that we can pick out differences but it will be largely sort of shades of gray I think some of the surface is very bright white pure ice ranging to sort of more grayish colored ice so you you know the idea about taking a photograph and then enhancing the color helps you scientifically yes to make the distinction between one one one thing and another yeah when we take images of the surface we take them in many different wave bands in in the electromagnetic spectrum so it's not just broadband visible light we take it some in the near infrared through to the near UV and when you combine you take multiple images when you combine those in different ways it can pull out features that that tell you about the composition because different compositions respond in different ways to to light in different ways and you can see more if you process that that photograph yes that's right so am I going to be able to take pictures like this with my 12 megapixel camera I know some cameras nowadays have like a like an infrared set but usually the the filters on these cameras are broad yeah broad wavelength so yeah so you catch everything with the camera just yeah and and looking at the photographs I mean these are very detailed high resolution photograph you can see tons of stuff with that with the Galileo imagery because the way the Galileo mission worked was that it was orbiting Jupiter and would swing by Europa every once in a while but at different distances and at different positions on the catchers catch yeah so we had on the very close flyby as we had images that were as good as 10 meters per pixel so we could get little tiny areas of the surface at very high resolution but the more global coverage is at around 200 meters per pixel and lower than that so even so we can see you know a lot of detail in those 200 meter pixel images can you use an idea of how big Europa is I mean diameter is a conference yeah it's about 1900 miles diameter so it's a few hundred miles less than our own moon so it's quite a small body which makes it surprising that it's so geologically active and part of the reason for that is its position in the Jupiter system you have Jupiter in the center and then as you go out from Jupiter you have Io which is the very volcanically active moon Europa, Ganymede and Callisto and Europa experiences gravitational stresses between Europa's gigantic gravity and then the gravity of the other moons nearby which is less yeah which is less but it as they go around their orbits it's experiencing it it passes by Io it passes by Ganymede and it's experiencing this gravitational attraction which which stresses the surface of Europa and this causes those cracks we think that we see the very long enumeration. Yes and it also induces a heating a frictional heating in the interior which we think is why there's liquid water there in the first place it's too cold out there for liquid water just to stay liquid there has to be this continual uh frictional heating because of this gravitational flexage. So now let's get to the big the big point here you have some evidence to suggest there are microbes no I don't don't say that but um to conjecture that there are maybe microbes speculation is um Europa has surprisingly look Europa has more liquid water on it than the earth does and we know on earth where everywhere where everyone is and when you say water you're saying the same thing we got here H2O H2O plus or minus you know salts like the ocean here is salty yeah um and on earth wherever we see water we see life so Europa is arguably the most plausible place in our solar system other than the earth to find life because it has this huge global salty ocean uh and so there's intense interest to go back to Europa to sample this ocean if we can you mean get down there get down there I mean that may be some way off but there's ways we can determine the composition of the ocean without actually getting into the ocean um and and try to figure out if it is uh not just a habitable environment but if it is in fact inhabited wouldn't that be something yes it would it would imagine you imagine that yours are mine oh okay well um and if if um if there is life on Europa and we're talking microbes we're talking bacteria we're not talking you know the Loch Ness monster or anything like that but if there is life in that ocean it in all likelihood evolved independently of life on earth um which suggests that the evolution of life is not limited to earth yeah it's not a terribly unique thing so if you go to other stars other solar systems um yeah who knows what might might be going on there too but this really makes my head hurt but so if if you found a microbe there um it would be the result of um you know the water and the heat and the water and maybe some nutrients of some kind yeah and uh that microbe could give rise to a whole planet full of life yeah over time who knows yeah um it's it's certainly mind-blowing to contemplate yes you know and and what it suggests to me I mean just you know this planet is sort of barren right now there's nothing much going on in terms of life you don't you don't see any but then earth was too absolutely and so if you had a microbe and then you have a dead microbe and maybe some nutrients then now there's two microbes and one is feeding off the decay of the other one right and all of a sudden you have foliage and and then it gets of higher levels of life and before you know it you have something like earth but it wouldn't be the same they would probably have three eyes or something right well I think I think you know out of Europa because it's so cold out there I think that probably limits how far down the evolutionary scale you can go um so and it certainly wouldn't be something that humankind would witness I don't know if I'm sure because it's going to be very far in the future hundreds of millions of years probably or something like that yeah so let's look at some more photographs now that I'm all provoked let's see some more okay okay so this is an artist's conception of of what might be going on in the interior of Europa you see Jupiter in the background and then Io volcanic Io in the background too so we have this very cold surface crust that's probably minus 240 Fahrenheit at the surface but then as you go deeper down into the ice the ice starts to get warmer and you have the liquid water layer at the bottom so this is just an idea of what kinds of processes might be going on there might be cracks propagating to the surface that allow water to erupt through vents on the surface and then on the right hand side those sort of blobs of lightish blue within the ice that's that's an artist's rendering of of how warm ice might buoyantly rise up to the surface and in both cases in the case of water going to the surface or warm blobs of ice going upwards they impact the the surface geology that we see the surface geomorphology that we see and produce um features that we observe on on the surface so we see them we're trying to put together physics models of how they form and these are the kinds of ideas that we we try and put numbers to and those uh those sprays uh that's water erupting right is that is that what the rendition is yes because um we actually in the last couple of years have evidence from Hubble Space Telescope images um that there are in fact active vents of water vapor um on the surface of Europa which is incredibly intriguing results and suggests that when we do go back to Europa with a spacecraft we can sample those plumes and there may be um not only we'll understand what the composition of the ocean water is but there may be organics within those plumes as well so that would give us an idea of what is is down in that ocean that's a way of sampling the ocean without getting into the ocean how high are the plumes is it miles um yeah they're uh let's see up to about 200 kilometers so um that's serious eruption yeah so so they're very very large is there an atmosphere um not not as such there there are particles of gas around the surface but not not anything you really call an atmosphere and Matt Damon couldn't do very much with this at all could he no no he couldn't he couldn't um and actually one of the other graphics I've got will um it shows the the evidence for these plumes that let's look we got a couple more okay so um this was really really really exciting stuff um back in the Galileo era we looked really hard for plumes above the surface and we didn't find any but back in um 2012 some images on the left here were acquired in the Hubble space is that x-rated or something you have those little artifacts there there's something we can't see don't want to see not exactly it's not that exciting but um what this shows is a composite of um the the the pixelated area is is an area that was observed in the Hubble image of uh vapor hydrogen oxygen above the surface of Europa that was being um illuminated by the magnetic field of Jupiter so this was the first detection by a guy called Lawrence Roth from South West Research Institute in San Antonio Texas and he looked in three sets of images and only once did he detect these pixels represent that water vapor so then there was a great deal of interest in in re-examining um these images because because we only he only saw it once out of three times that could suggest that um it was a transient event that turned off turned on and then turned off again or that there was some kind of instrument problem and and there's always possible yeah so then there was a campaign of observing to um try and find these plumes again and in 2014 um William Sparks and his group um uh from the space science uh space telescope science institute in in Baltimore Maryland um used a completely different way of observing Europa they observed Europa crossing in front of Jupiter and the light bouncing off of Jupiter could illuminate any water vapor that might be around Europa so um that image on the right was another highly processed image that removed the background image of Jupiter but left along the south pole these enhanced things you can see much more detail with that yeah so the two independent ways of of observing these plumes found in the latter instance by Sparks they found I think three instances in 2014 where they observed these plumes out of 10 observing runs so um this this provides a lot more evidence that there are in fact these water plumes venting from the surface of Europa in the south polar region um which provides a lot of impetus for NASA's upcoming Europa mission to to go back and be able to sample those plumes when is that well this mission the next mission is currently in development it's been selected um so they're developing their instruments now um it should launch in sometime in the 2020s it will take some number of years to get there I'm not sure what the projected orbit is but it could be five six seven years to get there and then it will go into orbit around Jupiter again but the flybys are designed to focus on Europa so it'll do something like 45 flybys an image at very high resolution um send it back by by radio transmission yes so you don't have to wait for the satellite spaceship to get back no space spaceship won't come back oh it won't come back it's a one-way trip for that poor spaceship poor spaceship but it'll stay there for several years and um spend a lot of time focusing on answering these questions um how deep is that ice layer how deep is it to the ocean can we sample the plumes this is a graphic that shows the an artist's rendering of of the uh Europa multiple flyby mission the two big panels coming out of the side of the spacecraft here uh solar no ice ice uh penetrating radar ah how interesting the idea is to use this ice penetrating radar the antenna sorry at the bottom of the panels I should say to figure out how thick that ice shell is and how how deep you might have to go to actually um sample the ocean and in kind of an unprecedented move um when congress was asked to approve this mission they also said you got to do a lander as well so this would be an orbiting mission but they there's a study underway right now to figure out how costly it would be how much it would cost to put a lander on the surface and to land this this spacecraft in an area that seems to be geologically active and directly sample um perhaps the the organics the the molecules that that might suggest a biotech uh environment this is this is very exciting you're doing very exciting work thank you for sharing it with us Sarah and and I hope you come back and give us you know more of the you know the points along the way absolutely we don't want to wait till 2020 we wouldn't before then okay I will do thank you Sarah Sarah Fagan's HIGP SOS thank you so much for coming down Aloha