Now, I am sad to say that we are nearing the end of our show here at the Royal Society's Summer Exhibition, but we have just enough time for a very special guest who's going to tell us about a seven-year mission to the icy moons of Jupiter. That's coming up next. Michelle Dockerti is a space physicist who specialises in the giant planets, Saturn and Jupiter, and their moons. She's currently leading on the juice mission, which hopes to confirm if there are liquid oceans under the frozen surfaces of Europa, Ganymede and Calisto. And if so, could they support life? Michelle, thank you so much for joining us today. Thank you for inviting me. Tell me a little bit about how long your search for alien life has been going on. Probably my own involvement, the last 15 or 20 years, because I was involved in the Cassini Space Crop mission that went to Saturn, and my team made a discovery of outgassing of water vapor from one of the small moons called Enceladus. And we realised that there was a liquid water ocean underneath the surface of Enceladus. But I think for me, probably one of the most important realisations planetary scientists have come to in the last 15 to 20 years is the fact that if you're looking for liquid water in our solar system, you don't have to look close to the Sun. You can look much further away from the Sun in the outer planet, but it's not on the surface, it's underneath the surface. Yes, even though you're basically really far away and not getting much of the Sun's heat, that's not necessarily required to create liquid water. That's right. And there is a ball, there is a ball, just conveniently I will make you solve. So what we think is happening at the three moons that we're going to is that as they orbit around Jupiter, they orbit is not quite circular. And so at times they're closer to Jupiter and its gravitational field than on others. And when they closer, the moon gets squeezed a bit. Right. And so as it's orbiting around, it gets squeezed at different rates as it's going around. And that's helping keep the interior molten. Because of this movement, because of the movement of the moon under the effect of the gravitational field of Jupiter. So it's called tidal forcing or tidal heating is a better way to describe it. So as it's orbiting around Jupiter, the interior changes shape as it's going around Jupiter. That's really interesting. Now tell me a little bit, let's rewind back. What was your story about coming into the career and science in the first place? It was quite, we do know, I said yes to some things, I wasn't sure if I could do. But if we go back to when I was a child in South Africa, my dad built his own telescope. I remember he ground the sort of mirror of the telescope. And my sister and I did what we thought was the most important thing. And that was mixed the concrete for the actual base of the telescope. I mean concrete is the most important thing. As a structural engineer, there you go. And you know, if we hadn't been able to do that, then the telescope wouldn't have been able to stand up by itself. And they should have the most important thing. So in fact, my first view of Jupiter and its moons was through the telescope and our front garden. Wow. And I also saw Saturn and its rings as well. How old were you at this point? It was about 12 or 13 years. So quite a formative sort of experience, I guess. Yes, but I was at an all-girl school in South Africa and they didn't teach science. Not at all. And so in fact, I did maths and biology and accountancy. I think those were the my main three subjects. So no physics. No physics. Right. But I was good at maths. And I didn't know what I wanted to do. And I was fortunate. My dad worked at the local university and so I could get in for free. That's good. And they took a chance on me. The physics department took a chance on me and they said, okay, why don't you do a BSC? I didn't know if I could do it. But turns out I really enjoyed physics. But I got a PhD in applied maths. I then went to Germany on a two-year fellowship and then I was offered a job at Imperial College. And after about six months at Imperial College, I was asked if I wanted to put a magnetic field model together for a spacecraft mission that was going to Jupiter. I did not know it. I'll do that. I had a better sound, quite cool, so I said, yes. So it sounds like there's a good philosophy in life to do things that we're not really sure we can do. I think so. They're times you need to be brave. And you sort of learn on the job. I now think I vaguely know what I'm doing, but I see yes to something I wasn't sure of. But it was really exciting. And so they tell I got into planetary science. It's absolutely incredible. Now tell me about this very exciting sounding project. What does it stand for? What is it doing? Okay, so it's a rather long-winded acronym, but it stands for Jupiter Icey Moon Explorer. I like it. But what was really interesting is when we came up with the name, the European Space Agency said to us, really, juice, zip, that the best you can do, we're going to change the name after launch. Right. And then we were launched a couple of months ago and I said to them, are you going to change your name? Oh no, we quite like it. So juice is what it's going to be. It's memorable. So the mission's going to take about seven and a half years. You mentioned what is the objective of the mission? Okay, so they're two different objectives. One is to try and understand the Jupiter system. But the one that I think is the real driver is to get an understanding about whether there's the potential for life to form. And that's in these kind of subterranean liquid water environments. That's right. So there are three moons, three of the large Galilean moons, which were almost certain of good liquid water oceans underneath the surface. And can you give us an idea of the scale of these compared to planet Earth of the moons? Okay, so the biggest moon is Gennermede. And it is about the same size as Mercury. Okay. So it's about a third of the size of the Earth. And if there is this liquid water ocean on Gennermede, which we're almost certain there is, if it's a global ocean, there'll be more water in that ocean than there is on the on the water oceans on the Earth. Wow. So that gives you an idea about how much water they've scaled. Like the scale of the Earth. Yeah. Yes. But so if you're looking to see where the life can exist, there's four things that you need. Yeah. You need liquid water. You need a heat source of some kind. You need organic material. And then you need those first three ingredients to be stable enough over a long enough period of time that something can actually happen. And so that's what we want to do with juice. Is we want to confirm that there's liquid water there, confirm there are heat sources, we're almost certain there are, because the water wouldn't be liquid. Sure. If there wasn't a heat source, see if there's organic material. And then those are three of the four. Yeah. Four ingredients. Ingredients. We're actually searching for. And are you going to find like lockmess under there? Are we looking at the juice we were? No. So I'm what we what we're thinking will be there is bacteria of some kind. So I'm trying to think back was maybe the 1980s. There was a there was a submersible that was sent to the deepest parts of the oceans on the Earth, where it's really cold, really dark, and they found bacteria close to the ends with. Yeah. Yeah. Those are the kind of things that we're thinking amazing. Yeah. Really exciting. And I have a question for you from Professor Brian Cox. So should we have a listen to that? Of course. Okay. Michelle, I have a question and it's probably a very unscientific question. So feel free to say I'm not answering that. But what I'd love to ask you is when juice arrives in jupe to rob it and it makes those low flybys of Europa. Perhaps it finds plumes emanating from the oceans of Europa. And if I forced you to guess, do you think that we'll find evidence for biological activity in your open ocean? So what do you think? It's only a little question. I would be very surprised if we didn't. We won't do it with the two juice flybys, but we might do it with the NASA Europa Clipper spacecraft that's got 50 flybys of Europa. All you need to do is you need to find organic material in the plumes. And then the implication is that organic material is coming out from the ocean itself. So these are going to collect kind of material from the plumes. So then analyze. Yes. So you know, I think of the three moons Europa, Genomead and Callisto, Europa is the one where we think its liquid water is in contact with the silicate mantle. And so silicate will be leaking away from that mantle. But if we can fly through a plume as it's going awful, if we can't have clipper, NASA clipper mission can fly through the plume, then we can almost taste what's in the plume. I mean, that sounds very exciting, but there's a little bit of time to wait, I guess for a while. I know, I never do. We can do that, but maybe we'll see you back here in seven and a half years. Absolutely. Here's some things. I'm still standing. I'll be back. You will be. And we're going to talk about Loch Ness again. I'm maybe not.