As usual, we're left with a lot of questions. I think we've come up with a lot of answers. I think we understand a lot more about what's inside something like Jupiter than we did before. But there's still plenty of questions. In fact, there's some big ones. Does Jupiter really have a core? Did Jupiter form with all these planetesimals raining in? How much water is inside there? And we learned from Galileo, well, we learned from the Galileo probe that the region that the Galileo probe went into was really quite dry. Everybody made up the excuse that, well, it went into sort of the Sahara desert of Jupiter and that actually seems like that's really true. But how much water is really is in there? How much of the icy planetesimals did accumulate? How much just came in a core? What about exoplanets? Why are they so puffed up, do they have cores? Did some of them maybe the biggest ones form through this theskins stability method big questions still abound. What are we going to do? Well, there are couple of big missions going forward right now that are attempting to answer some of this largest level questions at Jupiter right now is the Juno Mission, the Juno Spacecraft. And it's the first space mission ever whose main job is to figure out the interior of a giant planet. It's not going to spend it's time going around Jupiter, taking pictures of the moons, making pretty maps of the weather. It really is focusing very clearly on what's on the inside. And how does it do it? There are three key things in the Juno mission, at least the way I look at it. One is, it simply makes very close flybys. Those very close flybys as we learned before allow you to do a much better job mapping out the gravitational structure of Jupiter, and in particular, the Juno spacecraft should answer that question. Is there a 10 earth mass core inside there or is there not? Juno should be able to tell you. The other thing that happens on these close flybys is that you're doing close flybys of the magnetic field. And we always talk about the magnetic field far away from the planet being very much like a nice dipole having a north-south structure like this. But close to the planet, it won't be that dipole is what's left as you get far away. Close to the planet you are much more effected by how the magnetic field is being generated inside the planet. So Juno, by measuring the magnetic field, close in on these close flybys, we'll learn a tremendous amount about the structure of that conducting metallic hydrogen layer. Another really important thing that Juno has is instruments that will allow it to probe beneath the clouds. A long ways beneath the clouds but at least some of the way beneath the clouds. And some of the way beneath the clouds to really be able to finally measure the abundance of water and the distribution of water and see if those Galileo probe results were typical or were not typical. Really see how much extra water was incorporated into the outer parts of Jupiter after Jupiter formed. Did it form from a big core and then not many more planetesimals got stuck in there? Or, were there planetesimals raining in the entire time which could be a hint that some of those made it into that extra core that's on the inside. Just for fun, let's take a look at some of the nice NASA animations that show you what Juno has been doing since it got there. We're going to be looking down from the North Pole at the orbit of Juno as it comes in and approaches Jupiter. You'll notice very quickly there's something quite unusual about this orbit when it comes in. Look at that, it came in really close and goes quite far away. There it goes again, second orbit. Third one, comes in again. Fourth one. Fifth one, and it keeps on doing this. These orbits are incredibly elongated, they're come in really close and go out quite far away. They come in really close, we understand why, because we need those close-in measurements to measure the magnetic fields, the gravitational fields. Why does it go so far away? Well, the reason is, is because you can't spend very much time that close to Jupiter without being destroyed by the radiation of Jupiter. And so, it makes these daring little passes into the inside and then goes screaming back out where it's safe. Eventually, the orbit progresses so you're seeing different parts of the surface compared to where the sun is. The sun is still on this side and you're seeing the parts over here. Until at the very end, it goes smashing into Jupiter. We always go smashing into Jupiter at the very end because we don't want to go smashing into a place like Europa where we are someday maybe learning about what may be on the inside. If you now look at the orbits from the point of view of Jupiter, you can see that each successive orbit covers a different part of the planet. They have these weird curvy looks because the planet is moving underneath the orbit, it's not that the orbits themselves are curvy. And all you're seeing is the really close parts of it of course. But you can see the cover nearly uniformly the whole planet and with some very, very close flybys just skimming in the cosmic sense, just skimming the surface here. You also get some nice views of the poles. These are going to be the first spacecraft flybys that really take pictures from straight up and down Looking at the poles, they'll be looking at Aurora, the northern lights and the southern lights just like we have on the Earth. Another connection to the magnetic field and a connection to the satellites. One of the fun things about the Juno mission is that, though they don't have a scientific camera on the spacecraft, they actually put a camera on purely for public outreach purposes. So you can imagine that as Juno flies by the poles, we get these beautiful first time ever images of what it looks like from, here's a case from the South Pole looking up. And you can see the great red spot here, and you see all these beautiful little cloud systems going across here. And, well, it's dark at the South Pole, you can't tell exactly what's going on here, but you see all these wormy-looking little storms across there. Let's look at a few more of these. I particularly like this one. You can see the sunlight, of course, is coming in from this direction. And you see these little storm systems and you can see shadows, you can tell that these clouds are above the rest of them and you're seeing shadows off in this direction. Do you remember, that was one of those very first observations from Captain Noble that turned out to be wrong. He thought he saw shadows from the Great Red Spot. But here, we are, we're actually seeing these shadows from this systems here. And then as we get towards the pole, everything going into darkness. These will continue to be amazing as the Juno spacecraft mission continues. The spacecraft itself looks exactly like this. Spinning as it points back, this is the antenna that points back usually at the direction the Earth for communication, and all the instruments are packed inside up here. These huge solar panels are the biggest solar panels to ever fly in space. They have to be huge because this also the first solar powered spacecraft that's gone as far out as Jupiter. Everything else that we've sent to Jupiter and beyond has used radioactive power instead of this. These little jet-like things, I have no idea what these jet-like things are but they apparently go on and off. And just for fun, more distance view of Juno rendered against the surface of Jupiter, the surface, the clouds of Jupiter looking very pretty as it spins there in space. And finally, something that's supposed to explain how it is that Juno is going through the magnetic field getting close. So, Juno is in orbit around Jupiter, what has it found? Is there a core? It's still early enough in the mission that the data are still being analyzed and people are trying to understand what these gravitational signatures and magnetic signatures are telling us. But stay tuned with the answers will be very exciting. It will be interesting to see how excited the public is about it because its about the interior of Jupiter for the most part which is a little bit harder for people to understand. But you guys, having had it this section in this class, I hope understand a little bit more about why its going and are excited about what might be found.
