2018 New Evidence Found At Jupiter's Frozen "EUROPA"

we didn’t know till today that there is evidence from years ago that there’s something there Europa is one of the most fascinating bodies in the solar system we think beneath it’s icy surface is a global ocean twice the volume of all of Earth’s solutions combined in the late 1990s the Galileo spacecraft explored the Jupiter system it made about a dozen flybys of Europa it took observations from its cameras and from its magnetometer by discovering that there was an induced magnetic field at Europa we were led to the conclusion that there must be an ocean just beneath the icy surface of the Moon but there were some strange signatures in the magnetic field that we had never really been able to account for images of Europa from the Hubble Space Telescope have hinted at gases that might have come from plumes erupting at Europa the Hubble images had given an estimate of the height and width and I knew how fast Galileo was moving relative to Europa there are better tools now better computational techniques better computing that we can go back and look at that old dataset anew so my colleague ginger JA set up a calculation to see what would happen in the environment of Europa you there were such a plume and when he ran this simulation it agreed just beautifully with the data that we had collected reanalysis of the Galileo magnetometer data suggests that the Galileo spacecraft that’s closest flyby of Europa flew through the plume the Europa clipper mission is going to explore Europa to investigate its habitability if we find active plumes then we can sail on through them and sniff and taste that stuff that’s in the plume we can analyze the particles and the gases to get at the detailed composition of Europa’s interior good afternoon I’m Laurie glaze the acting director of the Planetary Science Division at NASA and I’m really excited to be here today talking with planetary scientists about this recent result confirming plumes on Europa I’m joined today by my co-pilot Johanna Wendell Johanna is a communication specialist here at NASA and to my left is dr Elizabeth turtle from the Johns Hopkins Applied Physics lab Zibby is interested in the moons of the planets in the outer part of our solar system to Zippy’s left we don’t have her yet but we have dr sinja ja who led the research that we just saw about in that video and Shin chose from the University of Michigan and he’s interested in magnetic and plasma environments on the planets and their moons and I’m hoping we’ll also be joined by dr. Margaret kibble s’en from the University of California Los Angeles and she was a scientist on the Galileo mission and she led the magnetometer investigation that discovered the ocean on Europa so with that I think I’d like to toss it over to Joanna and would you like to kick off this discussion yes I would this is a super exciting new line of evidence for Europa plumes which is awesome but I think before we really get into the nitty grita gritty of these findings we should really back up a little bit and figure out what is Europa and what you know where is it Europa is one of the large moons of Jupiter mm-hmm the planet Jupiter it’s somewhat smaller than our Moon mm-hmm and out at Jupiter’s distance from the Sun Europa’s surface is covered in ice in water ice yeah but beneath that water ice layer there’s evidence that there’s a liquid water ocean wow it’s really exciting that is so exciting and it’s so far away from the Sun so we know it’s covered in ice but how does how does an ocean survive out there a liquid ocean survive way out there well there’s a there’s an interaction between the different moons of Jupiter yeah io which is the closest moon to Jupiter Europa and then Ganymede mm-hmm and they’re in what’s called a

resonance yeah which means kind of like when you’re pushing someone on a swing every time they come back you give them a little more push and the moons do the same thing to each other in their in their orbits and that actually generates a lot of energy Wow so IO has silicate volcanoes just like Kilauea that’s interesting right now and as you move further out the moon’s get progressively colder okay so Europa has still has an icy surface but a liquid water ocean underneath a fairly thin ice shell and as you get out to Ganymede there’s a thicker ice shell but also with a liquid water ocean and keeps the water liquid but nice icy crust Wow so so then what is a plume so one of the one of the questions that we’ve had about Europa with this this fairly shallow ocean yeah is whether or not there’s current activity at the surface and one way that kind of activity can manifest itself is is by what we call cryovolcanism which is cold volcanism whoa and we see that Saturn’s moon yeah saladin okay they’re large plumes right all right liquid water and ice particles that are jetting out of the the South Pole of Enceladus yeah but it’s been a long-standing question as to whether we have that kind of activity at Europa as well yeah oh my god I mean that’s so like how do you how do you even go about trying to find plumes I mean what what are the different techniques we’ve used to even find these things on either of you kiddo maybe should yeah talk a little bit about yeah I mean of course from telescopes you could observe existence potential plumes so that was actually being done back a few years ago when Hubble first sent back images in 2012 and the scientists have found that you know hints that those images might contain signatures of potential plumes at a Europa a couple of years later they obtained further images and actually saw plumes occurring potentially at other locations from the first detection so telescopic observations certainly is a very useful valuable tool to search for plumes I just wanted to interrupt for a second when you say that that Hubble sent back images I mean are we talking about you know okay you know point-and-shoot image and we see the the vapor you know sort of cloudy I mean when you when you say image what are we actually seeing with our eyes in this image yeah so there are there are two kinds of I think techniques are being used so far from from Hubble one the first I think first set of emissions images taken by Hubble we’re looking at the emissions of molecules being striked by electrons that were generate emissions and those emissions at the specific of wavelengths will be captured by Hubble and the follow up like the aurora in our atmosphere a similar process and the follow-up observation from who I believe was looking at actual absorption of atmospheric water molecules of the lights so so the two different kinds of techniques are so far being used to look for plumes okay okay cool so but how do we discover them this time so this was what I understand is that we now we knew that there were plumes we believe there were plumes from the Hubble observations but you and your team went back and looked at the older data from the prior myths from from Galileo can you tell us a little bit about the Galileo mission or maybe Margaret can tell us a little bit about the the Galileo mission and the instrument that she led there yeah let’s get let’s get Margaret you get Margaret Lou can you tell us a little bit about the Galileo mission and magnetometer instrument investigation magnetometer instrument so the Galileo mission reached Jupiter in 1995 and was there for eight years in orbit for spacecraft in orbit around Jupiter and one of the key parts of the mission was to make close flybys of four large moons of Jupiter and there were 11 flybys of Europa and in a flyby the time close to the moon is of particular interest because that changes the way in which the charged particle gases in the vicinity of the moon move it slows them down it diverts the flows and changes the magnetic field and so for each pass we looked at changes in the magnetic field that were associated with

approaching of the moon and on one particular pass by Europa the spacecraft came very very close to the surface less as I remember less than 150 kilometers above the surface and it was on that pass that we saw signatures that we never really understood so I don’t know if you want me to go on at this point that was great so micro-opal thank you yeah so my question then would be what inspired you to go back into this what 20-year old data right you know there was this signature that maybe you never understood but what was the thing that made you go oh maybe we should check that out again and you know either ginger or Margaret can address well you can start changing okay and I think really were largely inspired by those Hubble detections published back a few years ago as I remember almost exactly a year ago we had a Europa clipper project science group meeting in Columbia Maryland the fifth meeting we had so other team scientists were gathering together and talking about science related to Europa and one of our colleagues Melissa McGrath so she was showing a summary of all the available couple images we had so far of Europa potential plume detection and the latest paper was just published about months before this meeting so she was talking about you know the locations of potential plumes in those images and that is the moment I really I think led us to realize that we had to go back to look at Galileo data because one of the flybys as Margaret just mentioned had a closest approach altitude that’s just couple hundred kilometers above the surface in the region that is very close to the repeat plume detection by Hubble so what I want to do is sort of paint a word picture here flying through a plume I mean what does this plume what do we think it looks like I mean are we talking about like a paper airplane flying over Old Faithful geyser in Yellowstone I mean what do we think is going on there well it would be it would be very tenuous you’d be able to sense it clearly Galileo sensed it yeah but Galileo didn’t see it so the so optically it’s it’s not necessarily very optically thick okay this is how we’d refer to it there not a lot of a lot of particles which is good didn’t do it right shot you know out of orbit but we do have some again some example from the Cassini spacecraft that did observations of Enceladus and its plume and in terms of the the imaging observations if you look at the plume if you look at Enceladus and hopefully Europa yeah when the Sun is on the other side so you’re kind of looking through the plume of the Sun the scattering by particles in the plume they can make them stand out very well even beautiful observations of the plumes of Enceladus and that’s something that we hope to do in the future with with Europa as well and so cool slightly silly question could it have seen a rain like in the mist like is there like a mist here that maybe it they could any any kind of plumes left I could see a rainbow I’ve always wondered that I don’t know that there’s enough signal at the different the different one with Europa clipper look at blue with a variety of wavelengths so maybe our first interplanetary rainbow and presumably you’ll do the same sort of experiment where you can put the Sun behind the plume and and see it and perhaps see if it’s possible to optically see it exactly exactly that’s one of the things that worked into the the plans with both the cameras on Europa clipper and the ultraviolet spectrograph which will be much more sensitive but there are number of other ways that we can look for current or recent activity in terms of you look directly for it you can also look for thermal signatures or what is tablets so you can look to see if there’s heat okay coming from the surface and in fact there is some some evidence that there may be heat in near the same region that the plume was seen correct yeah so the plume we identified in this particular study falls within the general region that we caught thermal anomaly that has been observed back again in the Galileo era published by scientists in the 1990s and so it appears to be that general region seems to have elevated temperature compared to the surroundings okay and why is that

interesting if there’s some you know region of heat we’re talking of course about ice so it’s you know not hot but hotter it’s hot it’s hot for it right so yeah what what is the significance of that thermal anomaly so the the this region of elevated temperatures so so that would tell us that the it would give us information about how much activity there is how much heating is is going into Europa how it’s being focused it also helps us understand the nature of the ice shell itself okay and one of the things we’re particularly interested in is exchange process is where we may get material like a plume where material is is coming from the ocean through the ice shell to the you know it’s above Europa and so it would be really important to understand the temperatures of the material that’s coming up of the ice shell beneath it okay very cool I wanted to thank you Margaret thank you so much and we also it looks like we have a question from the media here a question from will Dunham from Thomas Reuters and the question is to what degree do these findings suggest that Europa possesses the conditions to harbor microbial or other life forms and do these findings change your views about Europa as a leading candidate for hosting life direct that one to zu B again I think we know that that Europa has a lot of the ingredients necessary for life certainly for life as we know it there’s liquid water there’s energy there’s some amount of carbon material but the habitability of Europa is one of the big questions that we that we want to understand and one of the really exciting things about detection of a plume is that that means there may be ways that the material from the ocean which is mm-hmm likely the most habitable part of Europa because it’s very warmer right and it’s protected from the radiation environment okay by the ice shell so there may be ways for material from that ocean to come out above the the ice shell and that means we’d be able to sample it so that that’s one of the reasons this is so exciting just sort of back up about the Galileo data was Galileo able to tell what was in the plume I think the data we have the two datasets we analyzed in this study magnetic field and and the plasma wave data okay they do not directly tell us the makeup of the plume a composition of the plume well the we inferred was you know it’s it’s likely highly likely these but given the composition of the near surface material on Europa and we think it’s you know if it’s a plume is it’s largely composed of potentially water okay another question right another question from the media from Chris Gebhardt at NASA Space Flight comm and the question is what kind of impact do you anticipate this having on the up cope upcoming Europa clipper mission and will any instruments or mission aspects be tweaked and I think this is kind of a general question for all of us I know Zippy’s very heavily involved in the Europa clipper she’s actually leading the cameras on that mission so I’m sure she has thoughts but I’m kind of opening it up I’d like to know if other people think that this could have an impact I don’t think it will tweak the instruments at this point the instruments were specifically selected to be able to search for and study exactly this kind of activity so we have the the right instruments already onboard whether or not the trajectory can be tweaked so that the spacecraft flies closer to this area that and we were obviously limited by the laws of physics i’mso can’t get to every part of the surface close up but that’s an area that would be able to tweaked as well be tweaked got to be able to get deep enough to get down and fly through the plumes again so the closest approach the closest approach altitudes for Europa clipper get down to 25 kilometers Wow so they’re very close now whether that 25 kilometers so whether we can get that close in the region where the the plume material has been detected is limited again by the trajectory of the spacecraft so I don’t know if I don’t know if you’ve looked at how close clipper gets to that area I think I think in general as far as I know you know as its current plan is clipper as you just said they’d be eye contact more than 40 flybys close flybys of Europa and I and over 40 of them will have

flyby altitudes at a close approach less than 400 kilometers high and that’s certainly itself is good news the plume we identify in this study we saw the strong signal between the altitude or range of 200 to 400 kilometers so the closer you get to the surface probably the chance you’re seeing signatures of bloom will be higher so I think in that respect clear personally is in a very good position and so I think maybe the project you know it’s we have to look more carefully at you know which region is being covered by all these very low altitude flybys right okay so it’s less about the instruments changing and more about maybe where we send them or you know right and the observational strategy this gives us an initial place to start looking I mean obviously the plan was to do as global a search as possible for for plumes but this gives us a place to target in it yeah Oh what kinds of things are we actually looking for in those plumes where we’re talking about the ability to fly through the plumes and identify that the plumes are there but what types of measurements are we making other than just looking at them but are we taking chemical measurements and trying to understand what type of chemistry is going on in those plumes and do we have the ability to say yes there is microbial life where yes we do have instrumentation to be able to detect particles to be able to make chemical measurements is a mass spectrometer that would be able to tell what the chemical components of the plume or the atmosphere of Europa Europa has a very tenuous atmosphere but nonetheless there’s material there and so we’d be able to look at that right and we’d be able to detect dust particles we’ll get information about composition but it’s a long stretch to go from being able to measure the specific composition to being able to do that yes I know I know it’s a big job really I think it’s important for us to all really understand just how hard that is to do to actually say we’ve detected something that’s alive that’s a really big jump yeah right so we have to take the steps in order to get there right right to get all the way to that unless you know we put a GoPro on it and see if only so we have another question here this is from Twitter user Manish asks why is your oppa considered by many to be the most likely place in the solar system to find life great it’s a good question it is certainly one of the you know a high probability location the solar system it’s certainly not the only location that we’ve identified in the solar system that could potentially be a place where life is harbored so just some thoughts there well we know there’s liquid water and that’s of course for life as we know it requite and so that’s that’s one of the reasons and at Europa the liquid water is fairly close to the surface but but as you say there are a number of places in the outer solar system that may may be habitable and sell at us has a similar you know liquid water exactly that is that is venting which sounds bigger I always forget that Enceladus is much smaller okay it’s much smaller so just to kind of review so Enceladus and Titan or both moons of Saturn right so they’re a little bit further out yeah but you know do you think that were more likely to find life on Europa than at Enceladus or Titan or is it fairly even or it’s just more challenging in some of the other environments it’s oh it’s hard to say I mean that’s one of the reasons that habitability is such a key thing to study because we really right now have only the one data point right so what we want to do is gather more data points and we have different environments at these places Titan for example has a very rich very rich carbon chemistry and so it’s it’s kind of a carbon world as well as an ocean world and so that that’s a different dimension in terms of the question of habitability yeah so we have a great question from Facebook user Antonia which is related to what we’re just talking about which is are the plumes generated by the same physical causes as on Enceladus so we were talking about that we know there’s plumes on Enceladus we now have plumes on Europa that are confirmed so is it the same fizz process that’s that’s causing these plumes and maybe we can start by by talking about what are those processes you know what do we think is causing the plumes and is that maybe also happening on Europa right so I think there there have been there have been suggestions you know theories models being put out trying to understand for example Enceladus why plumes exist at Enceladus

you know they were the the suggestion has been you know this tidal flexing right right when you have a ice cover floating above a liquid layer and as the moon is orbiting around its parent planet I mean in Saturday’s to Saturn in the Europa we’re talking about Jupiter so it changes its distance relative to the parent planet so this flexing is changing as well so depending on the orbital phase how close and how far the moon is away from the planet you might see some locations it’s squeezing trying to squeeze the moon and making all this material coming out into space and that has been I think fairly well established at at the in solidus when Cassini sent back a lot of data that allow scientists to to see this correlation that different places in the orbit there’s more of it and that’s the thing we still don’t quite understand I think at the Ural buck right that’s a very sparse very few data points we write so far and when you say this the flexing sort of squeezes the material out do you mean like like you know squeezing a toothpaste tube and the toothpaste comes out you know it’s kind of squeezing the you know what’s it’s I think it’s more a case that that when there’s extension in the hydrogen when the when the crust is stretched it allows material to escape and then when there’s an expression when it’s being pushed together there’s less material that it okay yeah yeah we’ve got another great question here we got lots of good questions a question from the media Jesse Shanahan from Forbes science what is causing the unusual heating in this specific region so this is another great question for Shinjo the there’s it’s warmer there but what happened yeah I think I think the exact origin of my understanding of reading you know the literature has been the the exact origin of why this particular region seems to be warmer than other places is not really very well understood there I think different models theories being put out trying to explain this thermo anomaly could be internal and but also could be tied to the surface material the thermo properties are different due to other processes so I don’t really I don’t think we really know exact origin of the anomaly at this particular or how long lived it although the comparison being able to compare the Galileo data to the upcoming Clipper data will give us a bit of uh you know not it not geologic timescales yeah but you know but a few decades were to compare and those changes and so that’s going to be very interesting it’s absolutely yes yeah we’ve got another great question here Facebook user Sarah asks to clarify are these pop-up storms so looking at the radar now won’t be helpful in determining time and English timing of the storms so I guess of the eruptions right of the yeah right right of the plume right I think right we’re talking about yes so then you know first to clarify you know there’s this isn’t like a weather phenomenon happening we aren’t getting thunderstorms or anything like we said earlier Europa has a very tenuous atmosphere so what’s actually happening is these I know I know some people say guys are like sort of eruptions of water coming out of the actual surface of Europa and so you know can we use data to look at the timing of the eruption right now and we can we can do models for example to look at how long it would take to heat up that much of the crust you know that good area that we see if it’s something that’s penetrating the entire crust which at Europa is 25 plus or minus something yeah coming right it directly from the ocean and going yeah outside of Europa it’s not it’s not going to be as ephemeral as you know as storms or something like that because it takes a long time to break through the crust so if it’s not coming for the koushin what is the alternative where else could yes that’s a that’s a good question there there could be diappears or areas in the crust where warm water has risen up in Oakhurst yeah and is closer to the surface yeah there are some areas we call it chaos terrain so they’re just they’re just spectacular and a cool name yeah and if you look at them they you can see their plates of Europa the shell and you can see how they’ve moved around on top of this region so that suggests that there has been mobile material possibly liquid water a depth that they’ve been able to move around on like like icebergs in the you know in the sea here so if I before we go to the next question if I could so

I think one of the things I had trouble wrapping my mind around was cryovolcanism versus the Falken ISM that we’re very familiar with so is the so you have you know the ocean down there and then maybe some kind of isolated spots of warmer water closer maybe is there is there an analogy you could use for you know where magma is on earth is it like a hot spot versus you know what magma chamber under a volcano I mean I’m I don’t know this might not be the right crowd to ask you for one bit but is that I’m trying to imagine yeah complications is we don’t know what’s under the ocean okay right and we don’t know if the interior of Europa for example looks like IO which has large silicate volcanoes and so if there is volcanism under the ocean the same the same way we have sub ocean volcanism on earth then that could be one of the region the reasons that you get regions okay yeah but that’s that’s some we have no idea yeah so are you question for a Shinjo here are you able to I guess how well can you localize where these plumes are coming out to what kind of size scale do you think where the plume openings are how many plumes and have how can you are you able to characterize them in that way yes that’s something definitely we had to spend some time looking at in doing this study so when we first saw the data the magnetic field data and plasma wave measurements and we you know spotted out there swimming a long signal that seems to be very unusual compared to all the other flyby data we have look right and again you know based on the knowledge we learn from studying in solidus you know we know you know when you have a plume in outer space they’re able to influence the magnetic field they’re able to influence the plasma environment so that’s kind of the information the background knowledge we already had from from studying in solids and that guided us through our analysis and but to really make sense of the data to really interpret the data we had to go for numerical modeling and it’s exactly a numerical modeling we had to test different pool models in terms of location in terms of its size in terms of its density in column density for example and and I think luckily you know Hubble images are very very valuable in that sense because you can see from those images how big roughly the plumes are and I also tell us you know they infer column densities for the potentially detected plumes so we use those as constraints in our numerical computer model and we tested a large number of two models with the same kind of characteristics we saw in the Hubble images and the one we found out this one that seems to have a very good match to the observations for the magnetic signal and wave emissions so so Galileo spent three minutes within the the plume or is it three minutes of data and the the part the amount of time it spent within the plume is narrower than that the the magnetic signal seemed definitely shows a bend or a twist of the magnetic field else.we minute long okay and so not only the magnetic field strength changes abruptly it goes up and drops very quickly within about three minutes but also its direction you know because the magnetometer is API was the direction magnetic field and it also showed the very strength the pen the end of the field lines interest and that’s one of things we you know you see in the in the in the image which is put out and the plasma wave emissions are able to tell us there seems to be localized more dense plasma in that in that around the same time when we see the magnetic signal and how far do you know how far Galileo moved in that in that three minute yeah as Margaret though mentioned you know we know the speed of the space-time is massive kilometers per second so that’s three million long interval corresponds to about the southern comment okay at this altitude is about two hundred kilometers right which means that it could be even broader closer to the surface yes yeah yes we have another question from the media here and this is kind of following on to a question we were talking about a little bit earlier the question is from Mark kuroh Aviation Week and Eric Miller from wired similar questions will Clipper have a means of detecting biomarkers and how might the instruments compare to the ones on Cassini so we’ve already talked a little bit about the ability to detect mile markers but it’s a good question about how the instruments are similar or different from what flew on Cassini because Cassini did fly through the plumes on Enceladus and made some observations there as well so right the interesting can we like like Cassini Europa clipper has a suite of instruments that are designed to work together to understand in this case you wrote as a system and some of those instruments are remote

sensing instruments like cameras spectrometers that measure things from afar and then others are our instruments that measure things in situ or in place right in the environment of the spacecraft like a magnetometer or the plasma instrument or the mass spectrometer for example one of the big differences is that clipper has a sounding radar so that allows us to get to to get information about the subsurface structure of can you talk about that just a little bit more so Cassini carried a radar that could see the surface right but a sounding radar can actually measure and see what’s going on beneath the surface exactly so it’s designed to be able to it sends out signals and is sensitive to at wavelengths that will penetrate into the ice and then it is sensitive to detect the how those signals return and where they reflect in the crust will give us information for example if there is liquid water that’s perched up closer to the surface of the ocean that would be something one would be hoped to be able to detect with a with a sounding radar so is it that you know this you know beam is it light or it’s actually no it’s so much it’s a longer wavelength oh okay so this beam of something goes down and is it does it move or I guess does it travel at different speeds whether it’s you know solid ice or liquid I mean how do you tell the difference between the different structures right right so the the simplest thing to think about is the that you’ll you’ll send a signal and there’ll be a reflection off the surface okay right and so that’s that’s very easy to think yeah because it reflects off the surface and you receive it which gives you a measurement of the altimeter II of the telegraphy of the surface but then but then you’re exactly right the there will be waves that penetrate into the surface yeah and you can detect when they come back which tells how far how far they penetrated how they reflected and so but we don’t have that necessarily for install this is that correct okay correct we didn’t Cassini had a different type of radar as you said that was designed to do synthetic aperture radar imaging so that does surface imaging but doesn’t do deep deep sounding you know it would only penetrate you know tens of centimeters well actually to be fair it actually penetrated into you know little bits hundreds of meters into the methane seas on Titan yeah but but what the radar on clipper is designed to do is penetrate kilometers into the ice shelves that we understand yeah that’s so cool yes oh man chills again Wow we’ve got another question from social media and I think it was a great philosophical question for us to confer here Facebook user Steve asks could there be non carbon-based life with completely different requirements for existence this is always a great question yeah the only life we know is the life we know which is ours and so we think we understand what we’re made of and what it takes for us to live but right but what what other ideas are out there could there be you know how do we know what we don’t know that we’re looking so that’s I don’t think I know enough to well water-based life the water is a solvent that that enables the materials to combine yeah and there are other solvents and so it’s quite possible to think that there might be life based on the other solvents as well yeah I mean in the lakes of Titan methane and ethane and right lots of other things you know those aren’t water so if there’s life there then it would be right it’s possible that there might be places where there are methane-based places yeah sure but that’s still carbon-based but not water that water right right right yeah so right require liquid water exists that’s that’s the difference sorry yes other than carpet yes there be I mean yes we have another question from the media this is from Bart Lee he is Space Flight Insider how close will you rub a clip or get to Europa and how many passes will it make by the moon cool the the nominal mission design that we have right now has over 40 right now we have 44 close flybys of Europa and many of

those get down below 100 kilometers and several are down at the 25 kilometer all screaming over the surface which is about 15 miles I look yeah that is that is mind-boggling yes I mean that is yeah what is 15 miles away from DC you know I mean just right do we have can’t we give up can we give a reference it’s less than DC to Annapolis I think for sure yeah I mean that’s yeah I commute up further this morning into yeah like that’s very close I mean that’s so cool yeah but that allows us to you know to look at the surface in very close detail and it makes it easier to measure the atmosphere because they’ll be more material closer to Europa if their plumes the the further down into them the better sensing of the material exactly and it’s also better for measuring the magnetic field yes yeah if it got too far away from the plume proper let’s say there is in the plume then the signals will be contaminated with other effects you know the plasma is interacting whether you’re but constantly so if you’re too far away from the plume region you may not have a chance to really tell and what different aspects of the plume can you find out from getting that close and will you would you be able to see you know material falling back onto the planet you know or excuse me the moon one of the challenges of Europa compared to say Enceladus is that Europa is much bigger there’s a lot more gravity so when you see these images of Enceladus with the plumes stretching almost as far above Enceladus as a cell Enceladus is large that’s possible because there’s so little gravity holding material back but on Europa material won’t be able to get as high especially some of the particulate material so being able to fly lower through the plume gets you closer to the source and therefore makes it possible hopefully to sample more of the material that’s coming out yeah yeah I’ve got a question for Margaret she’s with us here and so Margaret could you talk a little bit about the magnetic field and the measurements that you took when you were at Europa and chin John has talked a little bit about the magnetic signal that he saw in the plumes but just kind of in general what’s the magnetic field like at Europa and how many places in our solar system do we have a magnetic field mm-hmm well that’s good let’s start with how many places do we have magnetic fields not all of the planets have planetary magnetic fields so Mars doesn’t have a planetary magnetic fields Venus doesn’t have planetary magnetic field but little mercury does so and all of the giant planets and as the Galileo made multiple orbits through the Jupiter system we established how the field varies with space and time and then we found each time we came close to one of the big moons the field deviated from what what had been present if the moon hadn’t been there and it’s almost as if a boat is going through the water and that pushes the water to the side and makes waves on the side so as the the gap of the material of Jupiter’s environment encounters one of these moons it gets diverted it gets slowed and the magnetic field changes magnitude and bends and we can relate all of those changes to properties of the moons and so how does the plume interact is it interacting with a magnetic field I mean how do we how are we using the magnetic field to actually and the plasma environment to find the plume okay that’s a good question because the material that is coming out from Europa is probably electrically neutral it’s probably dominated by water vapor which is a neutral material but there are lots of energetic particles in the environment of Europa and they ionize the material that is coming off so they make it an electrically charged material which can carry currents and it’s those electrical electrically charged parts of the plume that caused the changes in the

magnetic field that Jinja modeled so well and change the density of the electrons in the environment that were measured by the plasma wave instrument so it says it’s not a direct effect on the environment from the plume it’s a two-step process okay Wow thank you so much Margaret that’s great we’ve got another question from social media if this is a Twitter user Deepak asks what’s the temperature on Europa and can bacteria survive at those temperatures we haven’t really quite got this question from that angle yet mm-hmm so what do we know about the bacteria and could they actually survive at the temperatures that we think right well the surface temperature is quite cold right quite cold hundred Kelvin which is minus 173 and Celsius to figure out what that is in Fahrenheit for right let’s see but but that’s pretty darn cold but how old do we we we’ve talked about it being warmer in the water clearly though it’s a liquid water I mean and in part it could be colder than the freezing temperature of water because it could have salts and other types of chemicals in the in the water so it could be a little colder than than water but but we know they’re there bacteria on earth they can survive in in very extreme temperatures and certainly liquid water and Europa would probably be quite toasty for bacteria weather weather their levels in the you know in the ice that’s a good question too right right right well we do know of one extremely cold place that life yes can survive right Lake Vostok II right in Antarctica correct right right meet the ice show yeah so do let’s see just you know my quick internet searching here it’s about – what 8090 degrees Celsius so you know we know there’s some extrema file cold bacteria in there some like maybe not bacteria some microbes right down there so I guess that’s a start good all right we’ve got another question great questions twitter user jason major is asking what sort of effect might Europa’s plume activity have on other nearby moon’s surfaces so that’s a great question so shinjae you’ve looked at these plumes that how high they are in a sense of how big they are you know is there a sense or an a way for that material to talk today and perhaps be transported to another moon that’s really excellent question I think there are you know Europa has also in the past been found to be a source of neutral particles you know around the orbit of the moon and it has always been the puzzling piece of information observation we had in how to interpret the existence seemingly a neutral cloud around the Europa I mean we have long been thinking of IO as the major source of plasma to the Jovian environment mature into space but Europa also seems to be important also in terms of providing neutral materials so we have to understand you know the link between may be whether or not plumes are responsible for this type of phenomena we saw in the past a great question yeah I think good and we certainly see that in this attorney and sure Ella this is the source of the shirt the earring but yes I Oh in the door yes there certainly a lot of exchange of material sure the two so I have another question for Margaret and this question Margaret is back when you were working on designing and developing the magnetometer for Galileo and then the mission flew and it was a you know flying around Jupiter and and visiting Europa did you ever anticipate these types of discoveries would be made with the Galileo data no it’s amazing how hard it is to anticipate something that just hasn’t happened before even discovering that Ganymede had a planetary magnetic field one of the the biggest moon of Jupiter had a magnetic field was that was really quite a surprise discovering that we had signatures that seemed to require a sub I so ssin at Europa again it had been it had been discussed as a

possibility so we were we were aware of the possibility but it was certainly not of something that we thought was highly probable and then when we saw that there really was a signature of an ocean it was quite an aha moment so no I I don’t think I would have been tissa pated this end certainly not anticipated that we’d be finding out about plumes 20 years after we acquired the data that’s amazing that’s just like just incredible to have be involved in those types of incredible discoveries thank you so much Margaret we’ve got I think a few more minutes left for some of our discussion and then we’ve got a video to kind of close out our our hour here so maybe a few other topics well one thing I want to ask what people want what you would like the people that are listening and watching what you’d like them to away from from this discussion and what we’ve learned yeah from the from these two go ahead so the one thing I I feel extremely excited about was you know having seen now this result from our our paper really strengthens the case that I mean when you look also at the Hubble images combining the two kind of a two independent piece of evidence that now really strengthens the case that Europa seems to have plumes and they’re really I think it provides a great opportunity for future exploration of Europa alright now I’ve got a quick media question they want us to squeeze in oh yeah absolutely close out so how important is it to send a probe back to Enceladus to get comparative data and this is from Marsha Smith at space policy on on line and this is a great question so we’re saying after Europa Europa yeah yeah yeah I mean that’s what it’s one of the exciting things in the in the outer solar system is the diversity of the the types objects we’ve seen and we’ve today have only talked about the moons of Jupiter and Saturn only a few of those right and the diversity of objects and the questions we have about about moons as we get further out in the solar system about Ariel Uranus and Triton at at Neptune there’s a lot of territory out there a lot of terra incognita they’ve been really exciting to explore there is Enceladus yeah and it’s and it’s more than just an exploration you know a lot of what we do in planetary science is comparing different places you each other things that are similar and things that are different we take it’s a lot of what we do we look at how things work on earth and then we look at the other planets and make sure that you know we understand how things are working there so this is a big part of our approach so certainly anything to Enceladus would be fantastic very powerful technique yeah I’m that comparison yeah that would be great that would be great yeah so again let’s go back to zippy here and see if you have some takeaway things that you’d really like people to to take away from from this discussion from this new discovery why it’s so important to you and you know going forward I think it really demonstrates how much how much we are you know leveraging future exploration and discoveries on on past data sets and how much richness there is if we go back to data sets with a new context right with the HST data suggesting there might be something there going back and reanalyzing that shows us something something we hadn’t seen in the in the data before and something we didn’t know and it you know and and and taking that in the context of Cassini it just shows that the steps were taking moving forward but it also just really wets our appetite for what we’re gonna and I mean if we’re finding this stuff now what twenty years later I mean what else could we write I mean how much do more data is there to you know sort of mind through what are you gonna discover next lot of things to be looked at I think in the in the old dataset yes definitely one thing I learned from those are from this study yeah a lot of surprises a lot of surprises that the the old data are still incredibly useful right the new data are great but the the old day are also they hold a lot of subs we haven’t yet uncommon yeah thank you so much for your work you’re welcome okay I want to thank our audience the listening audience I want to thank the social media and all of the media for participating and sending in questions

there were some great questions we really enjoyed sitting here and talking about them we could talk for another hour I can talk about this result is absolutely incredible to to be able to say we really are confident there are plumes on Europa and have a mission that’s really already in development going and ready to make those measurements is fantastic yeah so to close this out we’re going to to leave it with another video with our associate administrator for science at NASA it’ll be Thomas sir Buchan today’s announcement of yet more evidence of blooms shedding out of Europa marks an outstanding leap forward in our search for life and habitable environments in the solar system there were hints of plumes in the past from the hubble space telescope the today’s finding which was mined from our decade-old data gives us further evidence to sink our scientific teeth into the fact that Galileo flew right through a plume tells us that on Europa these plumes are common and calling us to explore Europa has long been a high priority for exploration because it holds a salty liquid water ocean beneath it’s icy crust in just a few years Europa clipper spacecraft will be sailing towards that ocean world equipped with the instruments necessary to investigate both the origins and the plumes and what ingredients they contain Europa Clippers ultimate aim is to determine whether Europa is habitable possessing the ingredients we believe are necessary for life as we know it liquid water chemical ingredients and an energy source the robust ocean is one of the most promising places that could potentially harbour life in the solar system these newly confirmed plumes will provide another way to sample this vast ocean are we getting closer to answering are we alone in the universe the simple answer is yes perhaps that answer might come from a small ocean world like Europa thanks for watching