 All right. Thank you very much. Let's see, does the screen look good? Yes, it does look good. All right, awesome. Okay, thanks for that introduction. Yeah, so my name is Matt Billingham. Let's see, and today I wanted to talk a little bit about some of the recent work that I've been doing with some of my colleagues here at the Space Sciences Lab about Aurora on Mars. Which maybe not very many people know about because it's kind of new. Anyway, so let's see, to start here. Oh, so this is a weird picture. I'll explain more what this is at the end, but this is kind of a nice picture and where we should end up today. So let's see. I want to start with more than just Aurora on Mars, but Aurora in general, because maybe some people aren't familiar with that. And so Aurora, or what's sometimes called the Northern Lights, is a dynamic light display that's usually, you know, we can see in the upper atmosphere, usually near the North Pole. Also near the South Pole, but fewer people live there, so it's not quite as common. But all these pictures I found online of just different photographs people have taken from their ground, looking at the Aurora. So usually, you know, in Alaska or Canada or even Scandinavia, you get lots of these pictures often with snow on the ground, which you can see in some of these. Let's see. There we go. And so this is a time lapse movie. This is a greatly sped up. So usually over the course of tens of minutes, you can see these colors and these bands bouncing around in the sky. And this is one of the pretty active world displays here that we see here on Earth. So kind of fun. Let's see. And so these, where these occur, are high in the atmosphere, usually between 100 to 200 kilometers. So call it, you know, 100 miles on average, plus or minus, you know, 20 or 30 miles. So this is well above where airplanes fly, usually about 10 kilometers on your trans oceanic flights. And well below, say, the International Space Station, which is around 400 kilometers or about 250 miles. And so this little movie is from the space station. You can see the little solar panel in the corner that is looking down on the Aurora. You can see all these bright green bands just floating there in the atmosphere. Again, greatly sped up in this case. So what causes this Aurora? And so Aurora are caused by particles from space, usually electrons, but sometimes other particles. So you can hit the atoms and molecules in the atmosphere. And when they hit those atoms and molecules, those atoms become excited. They get into excited states. So this is, you know, a little bit of quantum mechanics. But you have the electrons in the atom and molecule itself will, you know, absorb some energy from the collision. And then when these atoms and molecules relax or calm down, they release that energy. They release that energy from light. And so these gases in the atmosphere will emit light. And it's basically very similar to how a neon light works. And so you have a basically a glass tube filled with gas. And you bombard it with electrons and you run a current through it. And then the gas starts to glow. And then you have neon lights. And if any of you remember the old CRT TV screens or monitors, they actually work in the same sort of principle too. We shoot electrons from the back of the TV at the back of the screen. And the screens start to glow. You can watch the moving pictures and all that. Very similar to how a neon light works. Not like our present day flat screens that use these different technologies. Okay. And so in a lot of pictures I just showed in little animations, we saw a lot of green light coming from our atmosphere. And that predominantly comes from oxygen. So in our atmosphere, at least down here on the surface, our interest mostly nitrogen, but also has a lot of oxygen in it. So the oxygen is the stuff we breathe. As you go a higher up in the atmosphere, you get more and more relative fraction, more oxygen. And so these electrons from space are hitting whatever's up there. So they hit a lot of oxygen. And you excite oxygen. One of the colors that emits is green. Sometimes it emits some red colors too, but predominantly green. And so we see this nice green aurora here on Earth. Okay. There's some other important stuff that comes into how the aurora is formed. And that has to do with the magnetic field. And so electrons from space, actually all charged particles are guided by magnetic fields. So in this is more physics stuff, but charged particles are basically the magnetic field tells a charged particle which way to go. And so Earth's magnetic field looks like has a giant bar magnet in the middle. It doesn't really. So actually what's going on is you have motions in the liquid iron core swirling around that generates Earth's magnetic field. But the shape of that magnetic field looks just like a big bar magnet where all of the magnetic field points out of one hemisphere and into another. And so here near the North and South Poles, it's almost vertical into the atmosphere. So the magnetic field guides you to charge particles into the atmosphere. And that is why we see the aurora here near the poles. Because that's where the magnetic field lines are most vertical and guiding those charged particles right down and to hit the atmosphere. Excite the atmospheric atoms, molecules and then they emit light. And usually we see the rings of aurora around the North and South Pole. Okay, so this is from a satellite orbits the Earth, looking down on the Earth. And maybe you can see here this is Antarctica. And so this is the southern lights. So we have the northern lights right now in the north and also the southern lights in the south. And again, this is over many hours, so it's greatly sped up. And you can see how the aurora is kind of dancing and moving around and changing shape and brightness. Let's see. And so often from space, when we look at the aurora, we don't look in visible light. Light our eyes can see. We'll often look in the ultraviolet part of the spectrum. We can't see ultraviolet. Ultraviolet has wavelengths that are shorter than violet. So we can't see it. We can build instruments, build cameras, put them on satellites so they can see an ultraviolet. And ultraviolet is useful because there's actually a lot of information you can get from looking at the ultraviolet light. Not a lot of information we can get from visible light. But from space. Actually, it's easier to see the aurora in ultraviolet than invisible because there's lots of, you know, the atmosphere reflects a lot of visible light, but does not reflect a lot of ultraviolet light. So when we look at the aurora from the ground, usually we study it in visible light, look at it from space. We study it in ultraviolet light. We study the aurora from the ground, the ultraviolet light, because the atmosphere does a pretty good job of absorbing ultraviolet. And so you wouldn't see very much from the ground if you tried to use an ultraviolet camera. But from space you can see a lot. And so, since it's ultraviolet light, our eyes can't see it. Sometimes we get crazy pictures like this where the color has nothing to do with the color of lights being emitted. So if we use all ultraviolet, we can't see it. We can't, our eyes don't know that it's there, so we can't assign a color to it. So here these colors just represent how bright it is. So red is really bright, and these sort of greenish and bluish colors are not quite as bright. But it again just illustrates, there's this ring around the North Pole, so you can see Greenland, Northern Canada. And the aurora around the North and the South Pole. Okay, so this is Earth, turns out. Other planets like Jupiter have a similar magnetic field configuration, a dipole magnetic field, where you have a bunch of magnetic field going into one of them, so you're one out of one hemisphere, so near the poles, the magnetic field is more or less vertical. And we see similar rings around the poles, and so here is Jupiter in visible light. So this is what we see when we come to a telescope, but up at the top we have the Jupiter's aurora in ultraviolet light. So you can see how bright Jupiter is here in visible light. If we try to take a visible picture of the aurora, all we'd see is sunlight reflected off Jupiter's clouds. So if we look into ultraviolet, Jupiter's clouds are very dark, but the aurora is very bright. So we can then see Jupiter's aurora and ultraviolet. And here's just a close-up view. It's much more structured and complicated than Earth, because there's a lot of stuff going on at Jupiter in terms of its big moons and all sorts of stuff happening there. That's a whole different topic about Jupiter's aurora. Let's see. Similarly, we can look at Saturn. It also has a dipole magnetic field like the Earth does. And so here is Saturn in visible light, and then Saturn's aurora is just happening to be from the south pole, and ultraviolet light. Again, if you try to look at this in visible light, Saturn's cloud tops are too bright. You can't really see the aurora, but ultraviolet light, Saturn's clouds are dim, and we can see this bright emission from this ring around Saturn's pole. And let's see. I have one more. So here's just, again, a time lapse. So several pictures. I think these are from Hubble Space Telescope. So watching the Saturn over the course of several hours and seeing how the aurora changes, just like we saw on Earth in the earlier time lapse movie, you can see the aurora basically change a little bit in size and shape. It gets brighter and dimmer. Okay, but this is not a talk about aurora on Earth or Jupiter or Saturn. It's supposed to be aurora on Mars. So what about Mars? So interestingly, Mars does not have a dipole magnetic field. What it does have are these small regions of magnetized rocks. So this is just an artist's rendition of what Mars's magnetic field might look like. And so this, I mean, this in itself is really interesting. It suggests that maybe early in its history, Mars had a dipole field kind of like the Earth does. But it doesn't anymore. It went away. Basically, whatever was going on in the liquid outer core of Mars, it may have generated a dipole field stopped happening. And then Mars' dipole field went away, dissipated. What was left over are these regions on Mars' surface where the rocks remember what that magnetic field was. They have these little patches of magnetic field rather than a global dipole magnetic field like Earth and Jupiter and Saturn. It looks much different at Mars. And so here's actually some data. So not an artist's rendition. But this is a map of where the magnetic field is nearly vertical at Mars. This is the vertical part of the magnetic field. And let's look at different hemispheres of Mars. If we made a map like this at Earth, I should have put one for this for comparison. It'd be much less structured. You would see maybe a band of blue at the top and a band of red at the bottom. And just some of these yellowish-grayish-greenish colors in the middle. I'm going to try and jump back. Some pictures here to show you this one. And so you can see in the north, there's vertical magnetic fields in the south, vertical magnetic fields. But everywhere else, there's no vertical fields. They're basically horizontal to the surface. And so if we were to make a map like this for Earth, it would just be these bands in latitude. Not all these splotches that we see here at Mars. Okay. So with this in mind, we can ask ourselves, well, then what does the aurora look like at Mars? Well, I would tell you, but that would be too short. So I wanted to give you a little bit of history first on how we discovered Aurora at Mars and how we got to where we are today. Okay. So a little bit of history. So actually Aurora on Mars was first discovered in 2005. So almost 20 years ago, 18 years ago, it was first discovered by this instrument with a crazy acronym, spectroscopy for the investigations and characteristics of the atmosphere of Mars. We just call it spy cam. That's much shorter. And this was an instrument, an ultraviolet instrument that was orbiting Mars on a spacecraft called Mars Express. So Mars Express was a mission that was launched by the European Space Agency. And it's still orbiting Mars, still taking data. And this is just one of the instruments that was on that satellite around Mars. And here is the first picture of the aurora on Mars. Actually, it's not really a picture. It's not very pretty, and it's kind of hard to interpret really what it is. And so this is actually what we call a spectrum, not really a picture. So in this instrument, the thing we call spy cam, it diffracts light, kind of like a prism. So light comes in and then it's spread out in wavelengths. Like if you shine light on a prism, it's going to make a rainbow. So basically light gets spread out from red to blue. This is ultraviolet light. So light gets spread out, but again, you can't see it. But it does get spread out in wavelengths. And so that's what the bottom here is, wavelength from 100 to 350 nanometers. The wavelength of the light. The human eye is sensitive to light from about 400 to 700 nanometers. So blue light is around 400 nanometers. So this is all at wavelength shorter than our eye can see. So I wouldn't say any of this. So this is all in the ultraviolet. So the spectrum, so it's not quite as pretty. It's not a nice picture, but there's a lot of information in here. Okay, so what are we looking at here? So this is a color bar where the brown stuff means it's very dim. There's not much light coming. And as your colors go from yellow to green to blue, it gets brighter. And we see these, these are these vertical stripes here. So that means there's light coming at very particular wavelengths. So not, not all the colors in the rainbow plus ultraviolet, but just very particular wavelengths of light are being emitted. And so what happens when you have aurora, you excite your atoms, molecules, they'll emit light, but they only emit very specific wavelengths. But what's interesting here is this little band, horizontal band right here. Where, okay, on this side, things are pretty dark, lots of brown color. That means very dark. Here's a big, a blip of blue right here. And then becomes, you know, brown again. It's a pretty vertical strips. And so this little blip right here. This is the first detection of aurora on Mars. But again, isn't very pretty. I'll give you that. But there's lots of, lots of information in here. So if we take a cut in this picture this way, right where that blip is and look at the spectrum. So basically look at how bright it is versus wavelength. And so here's the same wavelength scale from, you know, just over 100 to, you know, about 300 nanometers. So this is the same wavelength scale we have over here. But now instead of looking at, you know, finding colors, different brightnesses, we just look at the brightness then on this side. And so these little bunch of spiky things, as usually what a spectrum looks like, but the bigger spikes, that's where there's more lights coming at those wavelengths and more lights being emitted. And so we're able, if we look at a spectrum like this, one of the neat things about looking at spectra is you can figure out what atoms and molecules are emitting light. And also if you can do some other neat stuff and figure out what's the energy of electrons and hit them, that'll tell you how bright it is. But what I wanted to point out here is that we see light emitted from carbon monoxide, that's CO. That's not something that we have in Earth's atmosphere. So Earth's atmosphere, primarily nitrogen and oxygen, the atmosphere of Mars is primarily carbon dioxide. It's almost 95% carbon dioxide on the surface. If you go higher in the atmosphere, sometimes that carbon dioxide breaks up. So you have carbon dioxide, carbon monoxide, and also oxygen. And so we're seeing here in the spectrum, light coming from the carbon monoxide molecule and also from the carbon dioxide. So the brightest light here is coming from these wavelengths here that are carbon monoxide and carbon dioxide. And these are things we've never seen at Earth that have that much carbon dioxide and carbon monoxide, at least not enough to emit light in any appreciable amount. So this was the first discovery. Again, not pretty, but there it is. And this means something that people that study spectra all the time, but a picture like this really doesn't capture the public's imagination, does it? Okay, so later, about almost 10 years ago, another mission to Mars called MAVEN had an instrument called the imaging ultraviolet spectrograph, or we call IUVS. So it was a similar instrument to SPICAM. It looked at ultraviolet light. And again, as the light entered the instrument, it was broken up by wavelengths, like a little prism. And so you can look at the spectrum. But in this case, as the spacecraft, well, the instrument itself could move and basically scan across Mars rather than just stare at one spot. And so IUVS was able to build up images. And so here is basically the, I think the first image of what a rural on Mars looks like. And so basically what happens is this instrument would stare at Mars and it would have a mirror that would tilt back and forth and it would scan. And so these little rectangles here are strips as the instrument would scan across Mars. And you can see that there's some little places here where it's brighter than the surrounding area. And again, this is ultraviolet light. So we just picked a color. Our eyes can't see this. I guess whoever made this picked a color purple. Okay, let's look at it. Let's call it purple and see what it looks like. Okay, and so this is really interesting. So this is kind of cool. And you see these little bright squiggles here. You can line it up with a magnetic field map of Mars. And you can see that these squiggles will trace out the places of the magnetic field of purple. And this was the best, and I think the only picture we had up until 2021. It's a couple of years ago. That brings us to another mission. So basically in 2021, the Emirates Mars mission, sometimes abbreviated as EMM, it's also called HOPE or AMAL in Arabic, it's called scan orbiting Mars. And this was a mission launched by the United Arab Emirates. And it had another ultraviolet instrument on it. I would call them the Emirates Mars ultraviolet spectrometer. Often we just call it EMUs. But again, it measured the spectrum of Mars, but it had a much larger field of view. And you could scan across the planet and make images. Similar to this one, but as you'll see, much better in my... Okay, so these are the first global images of Aurora at Mars were taken by this ultraviolet instrument from the Emirates Mars mission. And so what are we looking at here? So on the left side of each one of these, this big bright crescent, that's basically the atmosphere of Mars has been illuminated by the sun. The sun's off the earth, sunlight shining on the atmosphere, and that scatters and reflects a bunch of sunlight, but it's really bright. And in a lot of these, we have dots that are surrounding Mars here. Those are actually stars that we can see, but here on the right side of all these images where it's dark... This is the night side of Mars. We wouldn't expect any scattered sunlight. And so all of the light coming from this dark side of Mars is Aurora. So now we're looking at Aurora on Mars. And these pictures are much better than the previous pictures because this instrument is much more sensitive than the previous instruments. So every time you send a new instrument on a new satellite out into space, you want to make it better than the last one. Whenever you make something better, more sensitive, you can see more stuff. And so with this instrument with emus, we see Aurora on Mars all over the place. Okay, so this Aurora that we see, often, almost always, not quite always, will often line up in places where the magnetic field of Mars is vertical or nearly so. And so in this case right here in this rightmost image, you see these sort of squiggles, they will line up with these regions here where the magnetic field of Mars is strong and vertical. And I'll show some pictures later that have some contours. What's also really interesting, I think, is we see also a rural emission where the magnetic field is not vertical. Where things don't line up with vertical magnetic fields. And so that is really interesting because that's completely unexpected. These eyeballs are completely unexpected. And so when we find things we don't expect, that's when we learn something new. We're going to try and figure out why is this happening. Okay, and it turns out, again, this instrument on the Emirates Mars mission is much more sensitive than previous instruments. And so basically we see Aurora almost all the time whenever we're looking at the night side of the planet. So if the spacecraft orbits Mars, whenever it looks at the night side, almost always we'll see some aurora. Okay, so most of the time, again, it's associated with the magnetic field that is nearly vertical. And so that's basically the... Some example images here at the top. I don't know if you can see the... There's some contours here, blue and purple. That's just showing the region that's strongest magnetic field. I have another picture that might be easy to see. We have the what we call the crustal field aurora. That's where the aurora lines up with the vertical magnetic fields. We see lots of examples of that. And again, interestingly, we see sometimes we'll see aurora that's not where the vertical magnetic field is. It's just called the patchy aurora that just occurs away from the crustal magnetic fields, the vertical magnetic fields, which again is really interesting, not really sure why that is. And then even crazier is sometimes we'll see these bands or these lines for aurora that will cover basically an entire hemisphere. So as it was shown in this bottom row, what we call sinuous aurora. So going from north to south or from east to west, sometimes there's little squiggles in here. And this has no analogy to anything we've seen at Earth or at Jupiter or at Saturn. And so it's a completely different, different type of aurora that we've never seen before at other planets. So that's really interesting. And we want to figure out, well, why is this happening? We don't know yet, short answer, but that's one of the things that a lot of people are working on. Okay. So another thing we can do is now we have a few years of data of images from the Emirates Mars mission and we can look at them statistically. Okay, so just take all those images and pile them up on a map of Mars. So we have latitude versus longitude on these two maps. And this is just showing, you know, where is aurora on Mars most likely? So we have an occurrence rate. What percent of the time do we see aurora on these different locations? Let's see. So a couple of things I want to point out. First off, the aurora at Mars is very dim compared to Earth. And so we can see on this, on these, on both of these, we have like a three R and a seven R. Those are the brightness threshold. So R stands for railways and that's a unit of brightness and it's often used when you look at atmospheres. So a nice, you know, dark adjusted human eye can see a few hundred railways. That's pretty dim. A nice auroral display, at least like sea on Earth, like those first few images I showed of those nice bright green aurora, those are, you know, usually several to many thousand railways. And so here we're looking at thresholds of three, not several thousand, and thresholds of seven railways, not several thousand. This is very, very dim compared to what we see on Earth. On average, okay, there are certain places where we can see bright aurora on Mars, so several hundred railways. But on average, the aurora on Mars appears to be pretty dim. Let's see, another thing I want to point out. Oh, so where the brighter aurora are most common are in these regions of vertical magnetic field. So here I think that the contours are much clearer. So you can see this with a blue and green contours. These are regions where the magnetic field is almost vertical. And where the magnetic field is vertical, that's where we see these bright patches saying, okay, this brighter aurora occur here more often. So all these little patches here where you see the bright spots of your brighter threshold aurora here is almost always where the field is vertical. But we look up here at the dimmer aurora, it's widespread, basically across the whole planet. There's almost always aurora somewhere, even in places where the magnetic field is not vertical. Okay, and one other thing I want to point out is this instrument doesn't... it looks in a different wavelength range. Again, we're looking at spectra over here in the ultraviolet. But you've got to pick, basically, when you make an instrument, what wavelengths to look at. And so this particular instrument doesn't see those carbon monoxide and carbon dioxide emissions like the previous instruments did, like I showed you that spectrum from stycams, carbon monoxide and carbon dioxide. What this instrument sees is from oxygen. And so here we have... this happens to be at 130 nanometers, but this is an emission that comes from an excited oxygen atom. So, again, electron hits an oxygen, that atom becomes excited, and when it relaxes, calms down again, it'll emit, sometimes it will emit an ultraviolet light at 130 nanometers. And so that's similar to what we see on Earth. If we look at an aurora in ultraviolet, we'll see this emission from oxygen at 130 nanometers. Okay, so I just wanted to summarize some stuff and compare and contrast with what we see at Mars, what we see at Earth. Okay, so in general, you know, aurora occur, or particles from space hit the atmosphere. Those atmospheric atoms and molecules get excited, and then when they relax, they emit light, and that's the light we can see. And usually, almost always, but not quite always, aurora occur for the magnetic field is vertical, because the magnetic field is basically guiding those charged particles for the atmosphere, and that's most easily done when the field is nearly vertical with respect to the atmosphere. And that's what we see at Earth and at Jupiter and at Saturn, and sometimes at Mars. At Mars in particular, let's see, the aurora is patchy. Like its magnetic field is patchy. And so that is very much unlike Earth. So at Earth, you usually have this nice continuous ring around the pole due to that large scale, you know, homogeneous magnetic field. Let's see, Mars, not like that, very patchy. You can see patches of aurora here and there. Let's see, like the brightest aurora at Mars, most often occurs where the field is vertical or nearly vertical. That is very similar to Earth. However, there's that widespread dimmer where the magnetic field is not vertical. So again, that's not something we see at Earth. We see the aurora where the field is vertical and no aurora usually where the field is vertical. Let's see. Another similarity is we see aurora from oxygen. So that's, let's see here from this picture. This is all coming from oxygen. And so we can see that and that's very similar to Earth because most of the light that we see from Earth's aurora is coming from oxygen. However, we also see aurora coming from carbon monoxide and carbon dioxide. And those are gases that aren't as plentiful in Earth's atmosphere. So we don't see any aurora coming from those molecules at Earth only from Mars. And so there's some similarities with Earth and that there's some really important differences from Earth's aurora that we see at Mars too. Okay. And I do want to say that all the observations that I showed is from Mars are from the ultraviolet. But as we know from studying gases in Earth laboratories, oxygen, when you excite oxygen, it will emit ultraviolet light and it will also emit visible light. Same thing with carbon dioxide. You have a laboratory bombarded with electrons that will emit ultraviolet light but it will also emit visible light. And carbon dioxide will often emit a blue color. And so you'll get green colors from oxygen but blue colors from carbon dioxide. So the fact that we see these emissions in ultraviolet coming from these gases says, well, at the same time, these gases are probably also emitting visible light. Just our instruments can't see them. So the conjecture here is that probably occasionally the aurora might be bright enough to be seen from the surface in visible light. And so I wanted to show this map again. This is from the picture again. This is from the title slide. So basically showing just one individual image looking at the aurora on Mars. And again, these brighter little features, brightest features here trace out the vertical magnetic field, magnetic field here. But this is where we see the brightest aurora. And so the thought is that maybe someday if we get rovers in this area, right now there's been no rovers at this area where the vertical magnetic fields are, or someday we get people in this area, they could be able to look up and perhaps see some aurora in the sky. And I picked this particular picture to add a lot of green, that'd be from oxygen, but also some blue mixed in here. Which on Earth comes from nitrogen but on Mars we come from the carbon dioxide. And hopefully a picture that someone might see someday of a aurora on Mars but taken from the surface of the planet, invisible light that our eyes can see rather than this ultraviolet light from space. And that's just much more, I don't know, visually engaging to actually see with our own eyes aurora on Mars. And so I think that's all the big stuff I wanted to say. And so I splashed my email address up here in case you have any lingering questions. But I think I'm happy to take questions now also. Yes, Matt, we have a couple of questions from Valerie. She said, when you say dim, does that mean dim to the UV sensors only? How might that relate to visual spectrum? So, good question, yes. And so yeah, as far as what we see, I call it dim because that's dim in our instrument, in our ultraviolet instrument. Right, and so people study, basically you have a gas, you've bombarded with electrons, and you see, okay, how much light is emitted in ultraviolet versus how much light is emitted in visible, and look at the entire spectrum from ultraviolet to visible, even what we can see. And so that, it depends a lot on the energy of the electrons that come in. You know, basically what excited states your atoms, molecules get excited to and what emissions come out of that. But there's been some theoretical work done recently to say, okay, if we see this much brightness in ultraviolet, what does that correspond to in terms of visible light? And people have suggested, like I kind of suggest here that the brightest aurora should be visible in visible light. So we should be able to see it, say with an instrument like the human eye, should be able, in some cases, to see that kind of like, let's see, yeah, kind of, you know, this is an Earth image, but maybe someday we'll see some glow like that in visible light. But yeah, we can do that calculation to figure out how bright it would be invisible. And it should be just above the threshold of what humans can see. Thank you, Matt. A question from Claire. What theories have been put out for the aurora areas that don't line up with vertical magnetic fields? Oh boy, that's a good question. Well, okay. So I guess the ideas that we have is that the, so basically these maps of the magnetic fields that we try to show here, like these contours here that show the vertical magnetic field. So this is a magnetic field that only comes from Mars itself, from the crust, from the rocks inside Mars. And so these are regions where you would expect the vertical magnetic field to be. So there's also a magnetic field that comes from the Sun. So basically all the planets are exposed to basically what we call a solar wind. It's the particles coming from the Sun and the Sun's magnetic field is dragged along with it. We call it the interplanetary magnetic field. And so that basically permeates the solar system. Okay, why am I saying that? And so what can happen is you can have this interplanetary magnetic field interact with the field, the magnetic field from the crust of Mars. And so what we think is happening is that, okay, there are actually vertical fields there, but they're not coming from Mars itself. They're coming from the interplanetary magnetic field. And as that basically wraps around Mars and interacts with the Mars's crustal magnetic fields, you can get places where it's locally, locally vertical, at least into the atmosphere. So you can guide particles in that way. And so it's what we call an external magnetic field that can guide the particles into the atmosphere rather than a magnetic field coming from inside Mars. And I think that's our best guess, because we shouldn't be able to get particles to the atmosphere. Electron shouldn't hit the atmosphere if there's no way to get there. And so we think there's got to be some sort of vertical magnetic field or at least almost vertical magnetic field that's the particles if you hit the atmosphere. So that's our idea at the moment, but we're still studying this stuff, trying to figure out why we do see Aurora in these places where we wouldn't expect to. Thank you, Matt. Another question from Valerie. If the Aurora move, what would cause them to move? Oh, golly, that is a really good question. So, okay. So we see Aurora, you know, even at Earth and at Jupiter and Saturn, and even at Mars, we have seen that. So we can take pictures a few minutes apart and we'll see that the bright areas move a little bit. And so it either comes from either the source of the tripartite or the source of electrons is moving. And so, you know, had some source of electrons over here and now that sort of move somewhere else. And so they are guided into the atmosphere. They hit a different part of the atmosphere. Or, that's one option, or you can have the magnetic field move or wave around a little bit. And so we think the magnetic field is, you know, basically fixed, just not really fixed. The magnetic field can move around a little bit, especially when you had these interactions with the interplanetary magnetic field. And so, as interplanetary magnetic field interacts with the crustal field from Mars, you can basically move around that crustal field a little bit. Well, it doesn't move in a rock. They can move up in the upper atmosphere, which I should clarify that. And so, as we see the Aurora moving, that's telling us one of two things. The source of the particles hitting the atmosphere is moving or the field itself is moving, or both. It's hard to distinguish between the two. At places like Earth and Jupiter and Saturn, okay, there you have a very strong magnetic field. And it's basically too strong to move around much. And so there we think the source of where the electrons are coming from is moving around in space. At Mars, we can't say that for sure, because it fields a lot weaker and is able to be pushed around more by the interplanetary magnetic field. So it's either the source of particles is moving, the field itself is moving around, or both is happening. And that can cause the Aurora to move. Thank you, Matt. And question from Mitra. They ask, how do solar magnetic fields and solar winds affect the Aurora in Mars? So that is an excellent question. That is what we're looking at. There's people across the hall from me and a few doors down from me that are looking to get that exact thing. They're trying to figure out how do changes in the solar wind? How does that change the Aurora we see? Let's see. And so what do we know so far? So there does seem to be some change in the Aurora. So we have basically the solar wind can sometimes be faster, slow. And it seems like when the solar wind is basically faster or more dense, the occurrence rate of the Aurora on Mars goes up. Similarly with the solar magnetic field and our planetary magnetic field, certain regions on Mars, let's see, are more likely to have Aurora there or not, depending upon the direction that that interplanetary magnetic field points. And so I don't have any good pictures, but I've seen some other pictures showing if you have the interplanetary magnetic field point one way, we can make a map like this of where the Aurora are. And if the magnetic field points another way, we can make a map like this of where the Aurora are. And there are differences. So that's telling us we don't know exactly what's going on yet, but we do know that the direction of the solar magnetic field does affect when and where Aurora can occur on Mars. But that's basically the cutting edge of research right now. At least for Aurora on Mars is how does the sun, how does the magnetic field from the sun and the solar wind from the sun, how does that affect when and where and how bright and how often we see this Aurora on Mars. So hopefully in a couple years, the next talk will have a lot more information and answers to that question, but that's a, that's what we're all wondering about. Thank you, Matt. That's the last question in chat. But Emory and Claire said thank you for sharing this interesting information and Parker said there's so many things and you just fascinated with Mars. Cool. I'm very happy to share that. Thank you so much, Matt. We really appreciate you taking the time to share with us the causes of Aurora and why they appear and act so differently on Mars. I also want to thank everyone for joining the program. I hope you all find the presentation interesting to you. I will send out an evaluation survey together with Matt's presentation slide deck and link to today's recording. Please give us your feedback so we can continue to improve our programming. Again, thank you everyone and have a wonderful rest of this. Bye-bye now. Thanks.