 Welcome to the public night, everyone. So my name's Adam, but before I start, I'd just like to acknowledge the traditional custodians of the land that Mount Stromlo and Canberra sit on, the Nunawal and the Nemri peoples, the first astronomers. And so I'd like to pay my respects to their elders past, present and emerging. So I'm the first speaker. My talk's gonna go for about 10 minutes and then we'll have some questions. If at any point you have questions, please just pop them in the chat below and I'll get to them in all of the end. So we'll have about maybe 10, 15 minutes of questions depending on how many you throw at me. So once I'm done, Brad, who you just heard, we'll come back and he'll do some stargazing. And then we'll hear after Brad's done from our next guest at about 740 or so, Dr. Noelia Martinez. And she'll be talking about how you can use lasers to improve your, our view of the night sky. And after that, Brad will do some more stargazing and then we'll wrap up probably around quarter to nine. But with that out of the way, I will get started. So I like Jupiter. And hopefully by the end of this, I can convince some of you that Jupiter is a pretty great planet as well. But let's, you've seen now probably a few loops of this video I've got going. And this video was taken in 1979. And it was as the NASA's Voyager 1 spacecraft was heading towards Jupiter. And it was, it took a picture about every 10 hours, which is the time it takes Jupiter to turn around. And it did this for about 28 days as it was getting closer and closer and closer, literally millions of kilometers covered in these 28 days. And you can see some beautiful motion on Jupiter here. But who am I? What am I doing here? Why am I talking to you? So I'm the PhD student at Mount Strong Low Observatory at the Australian National University. And what does a PhD student mean? That means that I'm studying and trying to answer questions that science doesn't know the answer to yet. So I'm trying to answer questions about our natural world. And for me, I use the biggest telescopes in Australia to study stars red in color and cooler in temperature than the sun. And I do this by using their light and I split their light into rainbows. And every star has a unique rainbow. And I can tell a lot about a star from its rainbow and maybe even something about their planets too. But I'm talking about our sun and the planets around it tonight. So we'll leave that for another talk. So here's our solar system. And we've got a lovely graphic here. And I'll point out that the planet's sizes are to scale. And what that means is that Jupiter is really that much bigger than the Earth and really that much smaller than the sun, for instance. But the distances between them aren't to scale. So Jupiter isn't actually that close to that. But what we can see here, we've got the sun on one side and we've got our four rocky planets. We have Mercury, Venus, Earth, and Mars. And we have our asteroid belt, which is full of leftover rocks and material from when the planets were born. We have our two gas giants, Jupiter and Saturn. Then we have Uranus and Neptune, who are our ice giants. And then we have a Kuiper belt, which is where Pluto hangs out. And you can sort of think of the Kuiper belt sort of like an icy asteroid belt. But I'll just draw your attention to this bar that's blown up and it was just down the bottom of the center. This shows the distances in the solar system to scale. So you can see that Venus and all our other rocky planets are all quite closely packed together close to the sun. And then we've got Jupiter and Saturn and there's quite a big distance between that and the rest of the planets. And Pluto is way off. And it really just shows how big our solar system actually is. But what do I mean when I talk about a gas giant? So indeed any of the kinds of planets. So Mercury is a rocky planet and it essentially has no atmosphere. There's some gas there, but really it doesn't have an atmosphere. Earth, we're well aware it has an atmosphere. Indeed, we're quite thankful for its atmosphere. You can sort of think of its atmosphere like the skin on an apple. It's quite thin, but it is definitely there. Neptune is a bit bigger again and it has a really big atmosphere and it's what we call an ice giant. And we might say something like 20% of the stuff that's in Neptune is gas. Jupiter, on the other hand, has about more than 90% of the stuff that's in it is gas. But that doesn't mean that we could just like fly straight through Jupiter like it's a cloud because for the same reason when we go to the bottom of the ocean, there's a lot of water above you that's pushing down on you and it's why you need to stop marine to stop the pressure crushing you. Jupiter has a really high pressure on its inside. So any spacecraft we sent into its atmosphere would need to be really tough. But still, what's the difference between an ice giant and a gas giant? Well, Jupiter is mostly made of hydrogen and helium. And that's mostly, the sun is mostly hydrogen and some helium as well, plus some other stuff. But Neptune, on the other hand, most of its gases are heavier than that, stuff like oxygen. And when we mean ices, if we took the stuff that's inside it out, you'd get stuff like water or ammonia that would freeze in space. So there's a lot to talk about about Jupiter, but let's talk about one of the things that everyone knows about, the Great Red Spot. It's a storm that's been raging for more than 100 years. And it's literally about the size of the Earth, like the planet we are on, there's a storm that big on another planet. And so we've been observing it, and astronomers have continuously since the late 1800s. And in the 1600s actually, a permanent spot was observed by an astronomer called Giovanni Cassini. And Cassini is the namesake of the mission that we sent to Saturn. But Cassini saw this permanent spot, but then no one else really looked at it or wrote anything down for 100 years or so. It might be the same spot. It might not be, but in any case, just imagine that there was a cyclone or a big thunderstorm just above your house, and it was there for like your entire life, because that's no one alive today has ever been around for a Jupiter that didn't have this big storm. But the storm is shrinking though, and it's different colors at different times. Sometimes it's more red, sometimes it's a bit lighter. And the red color we think is probably from the ultraviolet sunlight, kind of light that gives you a sunburn, breaking apart chemicals in its atmosphere into different chemicals that are red in color. So let's go somewhere different. The pole, the North Pole of Jupiter. And so we didn't really have a good idea of what was here until NASA's Juno spacecraft went there. And that's a picture of Juno in the top of the slide. And Juno can, you know, all the Jupiter top to bottom and so it can see both the North and the South Pole. And what we're seeing here is a bunch of cyclones. There's one in the middle and there's a whole bunch of ones around it. And each of those storms is more than 4,000 kilometers across, which is about as big as Australia is wide. And the colors are a bit funny here, because Juno is actually looking in infrared lights. And what this means is it's the kind of light that's too red for our eyes, but it's the kind that security cameras or night vision goggles use. And so it's seeing heat. So the dark regions are colder and higher up in the atmosphere. And the bright regions are lower down in the atmosphere and much more hot. And so Cassini, not Cassini, Juno can actually see 50 to 70 kilometers beneath the atmosphere using this fancy camera. And we didn't know this was here before. How about Jupiter's stripes? And they're all different colors. They go at different speeds and some of them go in different directions. And so what we think is happening here is that the light colored bands where the gas is rising up and you get, once it gets cooler as you get to the top, you get clouds of ammonia forming. And ammonia is what we use in fertilizer on earth. And when these clouds form, they're lighting color, but then in the dark regions, the gas is going down and the clouds evaporate and you can see the darker regions beneath. And so these stripes are visible with a small telescope. And before Juno, we really didn't have a good idea of how deep they went into Jupiter's atmosphere. Is it just like a painting? Like you've got a ball and you painted some stripes on it? Or does it go deep inside? And now we know that they go about 3,000 kilometers right into the middle of Jupiter. And 3,000 kilometers is about as tall as Australia. And that's the last time tonight I'm going to use Australia as a measuring stick. Onto Jupiter's moons. These are the four Galilean moons. They were discovered by Galileo hundreds of years ago with one of the very early telescopes. Each of these is about the size of our own moon. And just think, on earth, the tides in the ocean, we've got a high tide and a low tide, of course, by the way the moon is. The moon is pulling on the earth and pulling on the ocean. Just imagine how wild the tides would be on our planet if we had four moons the size of our moon. Pretty wild, but that's what's happening on Jupiter. And so each of these moons is not only pulling on Jupiter, they're pulling on each other. And so what that means is you're actually kind of changing the shape of the moons and heating them up. This is why Io is a volcano moon. And why Europa, you would think it's too far away from the sun to have water, but underneath its icy crust, there is a liquid water ocean, which is one of the best places we think in the solar system to look for life. Ganymede is the biggest moon in the solar system. And Callisto is the furthest out of them. So it's a bit different because it doesn't get tucked on as much by these really strong tides. So here's just two pictures of Io. The one on the left is an image actually and it's showing a volcano on Io just erupting into space. And the one on the right is Io casting a shadow on Jupiter, which is pretty beautiful. So one thing that you may not know about is that Jupiter helps us explore the solar system. And so here I have a GIF showing off a little movie showing what happens when we launched the Voyager 1 spacecraft, which I mentioned earlier. The speed that a spacecraft goes is limited by the rockets and our rockets are only so big. So if we wanted to get really far out to Jupiter or Saturn or further, we're limited by our rockets, but we can do a trick. We can use the gravity of the planet to go faster and change direction. So what we're seeing here, we launched Voyager 1, which is the magenta, the pink line, and from Earth, which is the dark blue, and then it goes by the light blue, which is Jupiter. And you'll see it kind of turns a corner and it starts going faster. It goes from about 13 kilometers per second up to 23 and then gets all the way out to Saturn. Voyager 2 did this in an even more extreme way because it slingshot it around Jupiter and Saturn and Uranus and Neptune. And this was made possible by the fact that all those planets were lined up at that point in time, but it allowed us to visit them all and it saved literally years of the trip versus if we didn't do this slingshotting. So finally, Jupiter can take a hit. So in 1994, a 1.8 kilometer diameter comet. So I think the size of like a suburb broke apart around Jupiter. Actually, Jupiter pulled it apart, just tore it to pieces with its gravity and it collided with Jupiter. And this comet is called Comet Shoemaker-Levy 9 after it was discovered by Carolyn and Eugene Shoemaker and David Levy. It's what we're seeing here. The big circle is Jupiter. The one that's off to the side, that's IOL volcano moon and the bright light that appears is like the explosion from when the comet hits Jupiter's atmosphere. And we see a lot of light in heat that it gets, that it makes. Here, we can see it happening as well. And this was actually taken by the Galileo spacecraft which was on its way to Jupiter at the time. And these less scars on the planet were visible for months because lots of different pieces of the comet fell in. And astronomers all over the world were looking at this because it allowed us to, it was the first time we saw something hit another planet other than the Earth. And it allowed us to see what's deeper in Jupiter's atmosphere because the comet kind of, you know, part of the clouds, so to speak for us. But why am I talking about Jupiter tonight? And so the reason for that is because Jupiter and Saturn actually are doing something special at the moment. And so if you imagine that you've got the Sun here and you've got the Earth, Jupiter is on the same side of the Sun and Saturn's just behind it, which means they're close to Earth because you could imagine Earth could be around the other side of the Sun. This means that they're really bright and they're really big. So it's a really great time to look at them. So if you go outside and look to the east, about now you'll see what I've got here and you'll see two points of light. Jupiter will be one of the brightest objects in the sky and there'll be another bright object here. And these rise as the Sun is setting and they'll set themselves as the Sun is rising again. And around midnight, they'll be right above you. And you don't need anything fancy to look at Jupiter either. So this is a picture I took just with my phone through one of the telescopes we had announced from last year, but actually the first time I saw Jupiter's moons was years ago. It was just using a pair of binoculars leaning against the gun tree. And even binoculars that you have today, probably better than the telescope Galileo had back in the day. So that's all for now. I'll take any questions that you popped in the chat. But thank you all for listening about Jupiter. And I hope I convinced some of you that it's gone up in your ranking of favorite planets. So I have a question here about how do different types of planets, rocky, ice or gas planets, form? And so for the rocky planets, that's pretty simple. You imagine you just get, if you get two rocks and you eventually rocks, we'll start to begin with how the Sun forms. You'd have a big cloud of gas in the universe so gravity wants to pull it together. But the thing is the cloud is spinning a bit. And so sort of in the same way that when if you see a chef making pizza and they throw the pizza dough in the air and it's spinning around, makes like a disk, goes flat. That is what happens with the solar system. So gravity pulls it flat, but it's spinning. So you get the Sun, the Sun is born in the middle and you get lots of leftover gas and dust that the planets can form from. And so as little bits of dust collide, they stick together and make bigger bits of dust. And this keeps happening and eventually it gets big enough that gravity can pull more and more bits to it. And that's kind of how you end up with a rocky planet. And for something like a Neptune or an ice giant, if it's a bit further out in the solar system, because the Sun kind of blows a lot of stuff away, a lot of the gas away. Out further, you can have ices form and not get blown away. And so out here, when you're forming that planet, you can get a lot of ices falling onto your planet, onto your rocky embryo. And there's more gas you can get as well and that's kind of how you get an ice giant. Because the bigger you get, the more gravity you have. So once a planet starts growing and growing and growing it grows quicker and quicker and quicker and quicker. And so there's kind of two ways that a Jupiter can form. A Jupiter-like planet could form by the same way. It just keeps pulling stuff onto it. Or there's some really weird physics that goes on in these disks that are left over after the stars are born. And what can happen is you can essentially get a bunch of the gas, it's something kind of weird and it just all gravity kind of and the other forces like pressure will come together and it just the planet forms really, really, really, really quickly. And so in that way, the planet like Jupiter won't really have much of a rocky core. It will have started from all this gas coming together quite quickly. And so that's kind of two different ways. And when we're looking at planets from the stars, trying to figure out how they forms and trying to inform us of how the planets in our own solar system did form. So I have another question. What would happen if a black hole that's small started sucking up Jupiter? So Jupiter, I mean, wouldn't really be a planet for very long? It'd get eaten and torn apart in the same way that Jupiter tore apart that comet. A black hole would be able to tear apart Jupiter. Black holes are strong enough to tear apart stars. But the thing is, black holes don't really suck. So if I like clipped my fingers right now and replaced the sun with a black hole that had the same amount of stuff in it, the same mass as the sun, we wouldn't notice immediately like the Earth would still keep going around the black hole because it would still have the same mass and the same amount of gravity. What would actually happen is we'd all freeze to death because there'd be no light from the black hole. So a black hole just has a lot of gravity but it doesn't just, you've got to get really close to it for it to be dangerous. But if you do, black holes can and do tear apart stars. So just don't get too close to it and please don't put my baby Jupiter too close to a black hole. So another question is, why did Jupiter form so far away from the sun? So that's a funny question because we actually think Jupiter has kind of changed positions over its lifetime. We actually think that the Jupiter kind of did a bit of roaming around early in the solar system when all the gravity of all the planets was a bit pulling on each other. And there was actually a lot more stuff then because the solar system made more planets than actually survived today. Some of them got fell into Jupiter and got eaten. Some of them got thrown out of the solar system. And so Jupiter's moved about a bit and it's ended up where it has today. But where a gas giant forms, there actually needs to be a lot of gas. And if you say too close to a star, all the gas has already fallen on the star or the stars blown it away. So another question, how many moons does Jupiter have? So Jupiter has 79 moons. And so the biggest ones are the Galilean moons, which I spoke about. But then there's lots that are much smaller. And if you looked at it, you would think that just looks like a better rock or like a meteorite. Because some of them actually are probably captured asteroids that came a bit too close to Jupiter and Jupiter said, that's mine now. Is there an order to the planet formation that could be expected to be repeated in other solar systems, e.g. IE, rocky, gashes, icy, et cetera. So we didn't really know what to expect when we started looking outside the solar system for other planets. Were we gonna find other solar systems and have rocky planets close to their star or then the gas giants and then ice giants? Instead, we found some pretty wild stuff we found. So in our own solar system, Mercury, has a year that's about 88 days long. Which means if you're on Mercury, you get a birthday cake every 88 days. But it doesn't have any air, so probably not a good idea to go to Mercury. But there are planets around other stars like Jupiter or even bigger, all but their star in a few days or even a few hours. And so as I've said, Jupiter needs to form further away from its star. And so for a Jupiter planet to get that close to its star, it's probably had to throw away a lot of the planets on the way. Because if Jupiter and our solar system decided to come in, it'd have to knock away Mars and go through the asteroid belts and Earth and Venus and Mars, Mercury, sorry. So there are also other kinds of planets that we don't have in our solar system. There's a kind of planet called a super earth that's kind of between earth and a nexium or a Uranus. And we don't have any of those and we didn't know those existed until we found them. And so there's all different kinds of solar systems out there in it. Might even be that ours is the weird one. Time will tell, we know about 4,000 planets around other stars right now. And I'm working to increase that number. So question, what is the red spot on Jupiter? So it's just a big cyclone that is the color it is because of the chemicals that are in it. A lot of the physics on Jupiter is a lot weirder than on earth because on earth, the atmosphere is thin like an apple skin, but on Jupiter the atmosphere goes much deeper. So you can get some really weird stuff going on. During the live stream, I saw odd blobs on Jupiter. What were they? So if you're referring to those videos, the odd blobs that appeared were actually the moons. So if you saw a black blob that appeared, it was actually a shadow that was just briefly skimming across Jupiter or a bright spot was actually the front side, like the day side of the moon, skimming across Jupiter as we were taking our pictures. And that's really neat. They look like they're errors with the image, but they're actually the moons of Jupiter. How many earths can fit into Jupiter? Quite a lot. I can't remember the number quite offhand right now, but a lot, a lot of earths. What do we think of the theory that Jupiter was responsible for the rocky planets being so close to the sun and bad? Well, yeah, as I said, Jupiter has moved around during its history. I mean, rocky planets will form closer to their star than gas planets will, but the actual present day positions of the rocky planets or all the planets are probably due to what Jupiter and Saturn have done in the past and how they've moved around. Okay, so an asteroid belt debris shows the possibility of becoming a planet or a moon. So the solar system made a lot more planets than survived, as I mentioned. In the asteroid belt, there's actually what we call a dwarf planet called Ceres. And Ceres is round like what you would expect a planet to be. And it's actually about a quarter of all the mass, all the stuff in the asteroid belt is in Ceres. And there's still a lot of stuff left around. So there would have been a lot of things like Ceres, a lot of dwarf planets, a lot of things that kind of got to be the shape of the planet, but a smaller than Mercury that got kicked out of the solar system or eaten up by Jupiter. The asteroid belt's kind of just what was left over. And the kite, the belt, the outskirts of the solar system is like the asteroid belt, except there's a lot more ices there. And the rock on a planet like Pluto is actually like kind of water ice because the water ice is like rock hard there. Where are the voyages now? Okay, so the voyager craft are actually just on their way out of the solar system. They're not heading towards any particular star, but they're still working and we can still talk to them. And they're learning about what it's like outside the solar system. It's kind of really exciting because they've been going for many decades at this point. But anyway, I think that's about all our questions. So I'm gonna throw back to Brad. Thank you all for taking the time to listen and ask me questions. Yeah, thanks, Adam. Thanks for that. Look, I made debate that Jupiter is the best planet. I think we can agree at least Mercury is kind of low down. Yeah, look, I wouldn't want to go to Mercury. No one wants to go to Mercury. That's right. Well, it's great because we're gonna do a little bit of stargazing and talk about Jupiter and Saturn, things that people can go right outside right now and see it. And if you don't have a telescope, well, we have some images for you. Now, one of the great things that Adam said though, I just always like to begin with is that, we live in Australia where we actually have some of the world's first astronomers. And one of the great things that we have in Australia, and this is in Victoria, is where do you aim? And where do you aim is essentially Australia's Stonehenge. This is a rock formation in Victoria. It's near Geelong. And some astronomers and scientists and anthropologists went and mapped the positions of these rocks. And what they noticed is that it actually traces the sunset at winter, the sunset in the middle summer and the equinoxes. It's a very good accurate calendar as a way of measuring the motion of the sun relative to the earth for timekeeping and all sorts of things. Now, I think the amazing thing about this is that it's estimated to be about 11,000 years old. So Stonehenge is about 6,000 years old. This is 11,000 years old. This is one of the oldest astronomical experiments in the world, and I think it's amazing. And we're so lucky and it's such a great, part of the legacy of history of the first scientists of this continent, the indigenous people here. And I think it's always cool because you may have heard in the news, NASA discovered a 13th constellation while that constellation's always been there. But the earth wobbles and the earth changes. The earth wobbles every 23,000 years and the stars move in relative to the constellations. So tracking the motions of the stars is a very important thing. Now, Adam spent a lot of time talking about Jupiter and Saturn. And so if you go outside right now or if you go outside pretty much anytime this month and a little bit later this evening, you can see Jupiter and Saturn in the nighttime sky. So as viewed from kind of the south, looking towards the east, we'll have Jupiter quite high in the sky over here and we'll have Saturn below it. Now, Jupiter is very bright. It's a really bright object. Now, one of the cool things is how to find a planet in the nighttime sky. So stars twinkle and in fact, well, later we'll talk about how we actually can fix that twinkling but stars twinkle because of turbulence in the sky. So your airplane shape stars twinkle, but planets don't. And the reason planets don't is there's multiple points of light coming through our atmosphere and our eye kind of blends that together. And because of that, we don't see the twinkling. So if you see a bright object and it appears to be not twinkling, it's most likely going to be a planet. Now there's lots of free software out there. In fact, this is a free software called Solarium. There's free apps you can use and point it to try and figure out if it is a planet. Now the night is pretty clear. So it's very easy to see Jupiter and Saturn and Jupiter rises and is visible right after sunset. Saturn a little bit later and it's visible all evening. So if you stay out a little bit later, you will see Saturn. And this is what Saturn looks like. So this is an image we took through the telescope recently. And so this is what you can see. So we've gotten it off the telescope for you to see here. And you can clearly see, hey, there's the ball and there's the rings. And that's the remarkable thing I think about Saturn is it looks exactly as described. We say it's a planet with a ring system and a body. And you can clearly see, hey, here's the actually the gap between the main part of the planet and that ring system. So I like Saturn because it comes right as advertised. Now, in fact, a few people asked how many moons earlier that Jupiter have and Jupiter has 79 moons. Well, Saturn has the most moons. Saturn has 82 moons. Now sometimes we can see Titan which is the largest moon of Saturn. I couldn't really see it tonight. But at other nights, you can really quite make it out as a bright dot. Most of the other moons of Saturn, we can't quite see though. They're small, they're fainter. But with Jupiter, Jupiter's quite interesting is because we can see its moons. So in fact, this isn't actually image. I just like to say there's a cool site called the NASA solar system site. You search for solar system NASA. You can kind of get a live view where everything is in the solar system. And this is what we would see through a telescope. We would see Jupiter. In fact, with the telescope, you can make out the gas bands of Jupiter on a clear night. You can start to see the red spot, just as Adam talked about. And there's four big moons of Jupiter. So as you're staring at Jupiter and if you have a pair of binoculars, you can go out and see this for yourself. As Adam said, Galileo's telescope wasn't that big. Not nearly as big as the ones Noella's gonna show in a few minutes. And so you can see these moons for yourself. And so currently, so right now is viewed from the Earth. If you go and look at Jupiter, Ganymede will be on the left. Io in between Ganymede and Jupiter. Then on the other side is Europa and Callisto. And the great thing is these moons move around Jupiter, especially relative to the Earth, this way we see it. And so if you look at Jupiter over the next few nights, you'll notice that these moons move. And as Adam said and talked about, this is something that Galileo has used to measure how the planets and the moon has changed around Jupiter and also how then the Earth was not the center of the solar system, the sun is. And we'll actually talk about another part of that, which is Venus and we'll talk about that in a second. So this is a really cool thing. So this is kind of what we're seeing right now is here's Jupiter with its brilliant gas bands and four of its main moons. And so if you have your pair of binoculars and go outside, you can see that for yourself. It's a really clear night here in Canberra. So hopefully where you are, you can see it. And it's just as clear for you. Now, Jupiter and Saturn will be up all night. And if you're late riser and you like to stay up even later tonight, around midnight, Mars will start to appear. So Mars will start to appear. Again, it'll be in the eastern sky. So what you'll see if you go out around midnight is Jupiter and Saturn is way above you. Right now it's on the eastern sky. Just going, I was just looking at it a few minutes ago and they're nice and bright in the eastern skies. Jupiter and Saturn are almost straight above at midnight. And you'll see Mars rising in the east at that point at midnight. And Mars is quite easy to see. It looks like a really red dot. We call it the red planet. And that's because it is the red planet. It looks red even from Earth. And it's a very bright thing. It's a very bright object able to see. And it looks as described. Now, Adam talked about this. This is kind of actually interesting relative to Mars. And that is that, well, firstly, we will see these all night. In fact, if you go out in sunrise, so if you'd like to wake up early, maybe you're gonna stay up all night. We're inspiring you to stay up all night. Well, if you stay up, you'll see Jupiter and Saturn as well. And stay tuned for after Nurella's talk because there's a really special event happening Sunday morning, 6 a.m. that I'm gonna talk about. And the reason Jupiter and Saturn and Mars are not only visible but so bright is as Adam said, they're at what's called opposition. So we have all of our planets going around the sun. It's kind of like cars going around the racetrack. And what you notice here is that Mercury, Venus, Earth, Mars, Jupiter and Saturn are all on the same side of the sun. And that means that the distance between Earth and these planets is the closest we get to what we call opposition. And by being closer, it does appear to be a bit brighter. Now sometimes you hear these rumors that's gonna be giant or in the sky. It is never like that, but they're nice and bright. Now there's also a practical point here. You may have heard that we're gearing up space agencies to launch three missions to Mars. In fact, the United Arab Emirates was supposed to launch their first mission to Mars this morning. Now, it didn't happen because of weather delays. They should be launching it on Monday. NASA has a rover called Perseverance Plan and the Chinese Space Agency has a rover planned to land on Mars as well. And there's this kind of rush, there's this convoy because you want to leave Earth at the close part to Mars. Now imagine we wait for another year and Mars is all the way over here. Well, that means that it will take a lot longer to leave Earth and get Mars. In fact, it doesn't even make it practical because even at this close distance, it still takes seven months to get to Mars. So opposition as a both being interesting to see because they're bright and we can see it right in the sky. It also means that for practical terms, for our space exploration, we can go and send probes to these planets a lot easier. And in the future, these are the times we're going to want to send people. We don't want people to be spinning an owl or a year chasing Mars. We want them to have a shorter trip as a possible. So it's a great night to go see these planets. Saturn looks great. And with a pair of binoculars, as I said, you can see those moons of Jupiter for yourself. I was just taking a look at it. Now, before we pass off, I know someone just had a couple of questions real quick. About where are you weighing? So there are some other historical sites in Australia related to astronomy and space and the traditional landowners. In fact, one of the more interesting, I think, things scientifically, as at both the discovery and historical interest, to some degree, is that there is an asteroid impact, meteorite, that landed in Central Australia about 100 kilometers northeast, rather, of Alice Springs about 5,000 years ago. And it's called the Hembrie meteorite. And in fact, when we can resume our public or private tours in the future, you can come and see that fragment up at Mount Stromlo. Now, the great thing is this big piece of metal that we have, which is this meteorite, it was big and it actually created a large crater in Central Australia. And it was 5,000 years ago. There were people living there 5,000 years ago. And there's been some work realizing that there is a dream time story. There is a recorded history of this event, the damage it did, the destruction and a record of its impact. So not only do we have a historical note of when, roughly, it happened, but we can also measure and get some understanding of the science behind it, how big that impact is, how fast it was. So it's in a really amazing way of combining some of the earliest observations we have, which this is what it is, and to still understanding how the asteroids in our solar system move around and sometimes hit Earth. So it's a great highlight that there's lots of parts in Australia where we can use these earliest, oldest observations to make some really cool scientific discoveries. Now, before I hand off to Noella, there's a really great question I wanna answer and that is how do the satellites make it past the asteroid belt? So if you see here, that's a comment, but there's some satellites around Jupiter, there was Voyager, there's all sorts of things. The asteroid belt is not that dense. It's actually relatively easy to pass through. So we kind of always have this picture that there's billions and billions of rocks tumbling around. And if you're gonna zoom through it, you're gonna crash. That's not quite the case. It's fairly spaced out, space is big. So you can make a trip going through it and we can relatively escape without hitting it. So because of the density, we realize it's fairly safe to go through the asteroid belt. It's not as maybe chaotic or crowded as it may seem in movies. Now, that's it for me for now. We're gonna do more stargazing after Noella's talk, but I'll let her hand over because she does some really cool things. She uses some of the biggest telescopes in the world, a lot bigger than what I've been showing and talking about, and uses giant space lasers, for lack of a better phrase, to correct for the effects of the atmosphere. And this is a really important part of astronomy and space that is being led by the people here, and is really changing our view of the universe. And I will hand over to her. Hi, everyone. I would like to start by acknowledging the traditional owners of the land on which we meet today, and I would also like to pay my respects to the elders past, present, and emerging. So now I'm going to share my presentation. Sorry, this one. Yeah. Okay, so I'm Noelia. I'm a postdoc at the Australian National University and today I'm going to present this talk titled, I Want My Own Star 2. Hopefully, after listening to this, everyone would also like to have their own star. So, let's go. Okay, sorry. Okay, there we are. So this is me. I was born in Spain 29 years ago. I studied industrial engineering. My specialty was electronics, and I got two professional positions as an engineer, first in the European Space Agency in the Netherlands, and then in the Astrophysic Institute in the Canary Islands in Spain. In 2016, I started my PhD in astrophysics in astrophysics instrumentation, so just building something. I finished October last year, right before moving to Australia to become a postdoc here at the ANU. Okay, so what do all these pictures have in common? Well, they show lasers that we're going to use to create our own stars. And this is what we call laser-guided stars. Laser-guided stars are artificial stars that we can generate wherever we want in the sky. So in order to understand what a laser-guided star is and how this works, we are going to start our journey by the beginning. So just wondering, as Brad said, why do the stars twinkle? Well, they twinkle because we look at them from the Earth and our eyes and our telescopes are surrounded by the atmosphere. So the light coming from the stars is perturbed by the atmospheric turbulence, and that's why we see it twinkling. So this affects our astronomical observations. And instead of seeing sharp and nice-resolved objects, we see blurred things like this. Or we cannot really resolve objects that are really close because they are really bright and the atmosphere makes them blur. But this not only affects astronomy, but also affects space applications. All of the ones related to sending or receiving light from a satellite or from an object in space. So this is the case of optical communications. Optical communications consist of sending or receiving information using a laser from the Earth to a satellite or from the satellite to the Earth. So because this laser will have to travel through the atmosphere in the same way the light coming from the stars, this atmosphere is going to perturb the laser light and we're going to lose some information. Also when we try to observe an object in space like a satellite or as a piece of a space junk, we are not going to be able to see what we are looking at. We are going to see this kind of blur thing. But what if we could actually change this and remove this negative effect? Well, in that case, we could see like much better objects like this one or we could actually resolve the center of the galaxy out of the galaxy, sorry, that we see in this animation. Or actually we could even look at the satellite and identify which one it is the one that we are looking at. So in order to do that, we need what we call adaptive optics systems. Sorry, this has to stop. Okay, sorry, yes. Okay, there, adaptive optics systems, sorry. So these are systems that measure and correct the atmospheric turbulence and remove the negative effect on the light. So how do they work? Well, we have our telescope capturing light from a reference object in the sky. This light will have to travel through the atmosphere and will get perturbed by this atmospheric turbulence. We'll go all the way to here, to our sensor or what we call wavefront sensor. This sensor will measure the atmospheric turbulence. We'll send this information to a computer and this computer will send some commands to a corrector element or the formable mirror. This element will change the shape to adapt to the perturbation that we are measuring. So it will be something like this. So we have our formable mirror, the light coming from the object with the atmosphere will be like this kind of blue thin but then we are going to measure it by the wavefront sensor, send information to the formable mirror and this will change the shape and get a much nicer image on our science detector. So in order to do this, our wavefront sensor needs a reference object in the sky to measure this light. This reference object can be the object that we are observing but usually this object is not bright enough. So we need to put another object close to that or we need to use another object close to that whose light we will be able of using with the wavefront sensor. So the reference object needs to be closer to the object of interest because otherwise the light will pass through a different amount of atmosphere. So as a reference object, we could use a natural star but believe it or not, there are not enough bright stars in the sky. And yeah, I also say like, nah, that's not true, but yeah, yeah, it is true. There are not enough bright stars. So, but why worryin' about this? If we can actually create our own stars. So let's generate some stars up there, wherever we want. And this is what we use laser bright stars to create a reference on the sky to measure the atmospheric turbulence with our wavefront sensor in the adaptive optic systems and correct for this atmospheric turbulence. So by looking at this image, how many colors or which colors do you think we use in these lasers to generate these stars? Exactly, green and orange. So we are going to continue our journey by explaining now the two different types of laser-guided stars that we can create. So let's start by the green one. We have our telescope here, we have the atmosphere with all the turbulence and these circles represent the dust particles in the atmosphere that are flying up there. So, okay, we have everything ready. We have set up our system. We press the bottom and boom! Well, hopefully it won't explode if we have done everything properly. And we will see just the green laser beam coming out of the telescope, something like this. But why do we actually see this? Well, because the laser is reflecting on each of the dust particles in the atmosphere. That's why we will see the green laser beam from the exit of the telescope to the upper part of the atmosphere, which is going to be around 20 kilometers above the Earth's surface. Below that 20 kilometers, we won't see the laser anymore because there are not going to be any more dust particles in which the laser will reflect. So this reflection on the dust particles are called the Ray-Lay return. But, okay, wait a minute. We need an artificial star or something with a star shape. Now we have a line or a cone of light. So we have to tell our wavefront sensor, our camera, to only capture a certain area of that cone of light. Otherwise, we won't have the star. So we need to tell the wavefront sensor, okay, we have our Ray-Lay laser by the star is what we call it here or here or maybe here. So where we could put our Ray-Lay laser by the star? We actually wanted to put it here. So the upper, the higher in the atmosphere as possible because we are going to use that light from that small area to measure the turbulence. So that light will travel downwards from that illuminated area to our telescope. So if we select the area in the middle of the light cone, we are going to miss on the turbulence information above that area. So we wanted to have our Ray-Lay laser by the star as high as possible. Okay, so this was our first type, the one that we call Ray-Lay laser by the star. Let's go now to the second one, the one that we use an orange laser for this. So again, we have our telescope, our atmosphere, and now we have a third element, the sodium layer. So this is a layer full of sodium atoms at approximately 90 kilometers above the Earth's surface. So again, we set up our feast system, we have everything ready, push the bottom, and what we get is the same as before. We are going to get the Ray-Lay return first because we are going to launch our laser, our orange laser now, and this laser is going to be reflected on the dust particles of the atmosphere. So we are going to see this Ray-Lay light coming out of the telescope. Then after that, once the atmosphere is over, at around 20 kilometers, we are not going to see any more of the laser, but something will happen up higher in above the Earth because the laser will keep traveling up and then it will reach the sodium layer. So at this point, the laser will excite the atoms in the sodium layer, and those atoms will glow, generating our nice sodium laser guide star at 90 kilometers above the Earth in such a way that we will be able of measuring the whole atmosphere volume below this 90-kilometer sodium layer. So this will look like this, and this is a real image taken in Chile in 2016. So we first could see the Ray-Lay illumination of the dust particles in the atmosphere by this orange laser. Then we will see the dark area a bit up where we don't have atmosphere anymore, and then we have our tiny, cute laser guide star up there. And then we also see Saturn here. So in this scenario, we will have our telescope like here, and then we will be measuring the whole atmospheric turbulence from our telescope to the sodium laser guide star. So our telescope is going to be observing Saturn and with information extracted from the sodium laser guide star, we can correct for the atmospheric effect and get a much nicer picture of Saturn. It's not that cool. Okay, so this is our second type, what we call the sodium laser guide star. So basically, laser guide stars are used as a reference for the adaptive optic systems. They measure and correct the atmospheric effect on the light. There are two different types. The Ray-Lay laser guide star that we can generate using a green laser and the sodium laser guide star that we need to use an orange laser. So anyone can guess which is going to be the next color of laser guide star. Maybe a multicolor one. This is actually not far from reality. So maybe you need to stay tuned for the future talks about laser guide stars and find out about this. So this is what like maybe the next generation of laser guide star is going to look like. But how is going to be the next generation of laser guide star creators? Right now, we are a group of people from all around the world, here in Australia, overseas, people from different nationalities, different languages, different backgrounds. We all work together to have our own stars up there on the sky. So if you want to have your own star too, you just need to know that you have to study science. Okay, so this is all for now. I'm happy to take any question that you have. I would like to first thank everyone for attending this talk. Thank you all to Brad and Brittany, who you don't see her, but she's in the background doing a lot of work. Thank you also to the Auslan interpreter and to all these amazing women that have sent me all these pictures for me to include in this slide. Okay, so let's go with the questions now. Okay, how does this correct the image? Okay, so we are measuring the atmospheric turbulence, right? And then the deformable mirror will change. So in a first iteration, let's say, the light comes to the telescope. The deformable mirror is flat. So we are going to get at the form light on the wave front sensor. This will allow us to measure the turbulence. We'll send the information to the deformable mirror. And the deformable mirror will change the shape to make the opposite shape of the turbulence. So we are going to subtract the turbulence information from the light. And then we're going to get instead of this blur image, a much nicer image. Okay, does this laser affect any airplanes flying by? Yes, it does. Actually, these are lasers that are usually with power higher than 20 watts. So just for your reference, one can burn a piece of paper with one watt. So if you just propagate 20 watts plus to the sky and there are airplanes flying by, we are not going to make the airplane explode. But we could get, I don't know, we would get the pilot blind, for instance, blind in the sense of like, it could like lose the vision in a really moment, in a specific moment, and that could cause some damage. But so in order to do that, we need to ask for permissions to propagate all these lasers. So there is, like, depending on the country, there is a standard that we need to use and an authority that we need to ask for permission for. Okay, so would a yellow laser light also be effective? Along with orange and green, it's in a similar wavelength range. Okay, so one could argue that the laser that we're going to use is orange or yellow. The important part is that the laser has the sodium wavelength, which is 589 nanometers. So we need to actually be at the exact sodium wavelength to be able to excite in these atoms. Any variation in the wavelength would imply that we are not going to excite at all any atom and then we cannot get this nice spot on the solving layer. Okay, so you point the guy, the star at where, I'm sorry, at where you want to observe, but does that affect what is observed? Well, you have to point the star out of your field of view of observation. So usually these big telescopes, so we are talking here about telescopes that are maybe two meters, five meters in diameter. So they are really big telescopes. So we usually point the laser in such a way that the field of view in which we are observing the interesting object, the science object is not affected by the laser light because otherwise it would introduce some information that we don't want on our science image. Why are the colors different? The colors are different because they have different wavelengths. So if we look at the spectrum of the light, there are different, every wavelength has a different color. So that's why they are different. So green has a 532 nanometers and orange or yellow, depending on who, look at that has the 589 nanometers, which is exactly the sodium layer wavelength. And that's why they have different colors. What is the absolute farthest distance you can shine a laser? Well, this depends on if you want to see it. So if you want to see the laser, then the farthest distance to which you can shine it is this 20 kilometers around 20 kilometers that the atmosphere lasts. Because below, above that, you cannot see it anymore. In terms of if you want to shine a laser to a satellite, for instance, you can. So you just need to have the proper receiver on the other side to be able of getting that laser. But yeah, you can. It will be bigger because the light will like grow, like will expand the diameter as soon as it goes up. But yeah, you can definitely do it. And it will be less intense. That's also because it will lose, it will lose power as in the meantime it's going up. Okay. Why orange and green? Yeah, so those are the colors that are most effective. So in this case, green is the most effective one. In the case of like seeing the Rayleigh, this reflection on the dust particles. In the case of orange is because it's a sodium wavelength. So we really need that one. But there were people investigating other colors. So there was some research using blue lasers. But in terms, because they were like looking at the different return that they could get with the Rayleigh. But so far, those two are the most common ones, okay. So you can actually change the surface of the mirror. What is it made of? Okay, so the mirror has a metallic coating like any mirror. But the key point is that this surface of the mirror has some actuators on the back. So the mirror, the mirror surface is really thin. So these actuators can move the surface of the mirror by a certain amount and that will change the surface. So it's not actually visible with the eyes because the amount is really, really small. But yeah, this really thin layer could be moved with actuators on the other side, okay. How do you make the lasers different colors? Well, there are different techniques of making lasers. It depends on the cell that we are going to use to shine that light. So this is a bit like a complicated to explain, but either really different, like a bunch of different techniques to make lasers. So from semiconductor materials to Raman fibers. Now, for instance, in Macquarie University, they are explaining the possibility, they are exploiting the possibility of using diamond to like generate this laser. Whose invention is this? I actually don't know whose invention is this? I know this has been around since the 90s. At the beginning it was military research groups who did this first. And then once they released the results to the broader community, astronomy started to use in it. How do you make a multicolor laser? Well, so the multicolor laser would be, it would be not the multicolor laser. The glow would be multicolor. So we will have a laser with a certain color, but that would excite different areas on the sodium layer and that would produce different fluorescence of these sodium atoms. Okay. Okay, I don't know if you have any other question. Okay. So if not, okay. Maybe we can wait just a bit in case we have more than any other question. And then if not, thank you again for attending this talk and I hope you like it. So now I think Brad is going to do another stair casing. Thank you. Yeah, thank you very much. And yeah, thanks for everyone loves giant space lasers. Actually, real quick, you are a new ailer. We, you know, on Mount Stromlo, there actually is a facility that tracks space debris and there are some previous talks on that, that you have one of these lasers. In fact, there will soon potentially be a newer one that you can see from the nearby area. And in fact, if you're on Mount Stromlo when it's nice and dark, you can see a green laser on there. So it's something, you know, we can see here in Canberra, which is amazing. Now, we're going to do a little bit of a continuing our stargazing session. And there is lots of cool things to see, obviously. Now we focus a bit on the planets in the beginning, but now we want to turn to some of the other objects in the sky. And in fact, this is a photo I just took and this is not even with a telescope. This is just with a mobile phone. And a lot of you may have mobile phones that have nice nighttime settings. This is really just taking use of a mobile phone, pointing at it in its night mode and taking image for three seconds. And what do you see? Well, we can see that we have the Southern Cross. We have the nice Southern Cross here. So there's five stars that we can normally make up or see of the Southern Cross. Now, one of the more interesting things I always think is next to the Southern Cross we have Alpha Centauri and Beta Centauri. Now these are called the pointers because they point to the Southern Cross but they are called Alpha and Beta Centauri. Now Alpha Centauri is I think quite interesting because it is the nearest star to us besides our sun. This is the nearest star to our solar system. And it's actually three stars. There's Alpha Centauri A and B and Proxima Centauri. Now Proxima Centauri technically is the closest one of those three, but it's also pretty small. Now what ends up being cool about this is Alpha Centauri A and B because they're close. We can actually make them out as two dots next to each other. Now this looks weird because it is. Instead of being one circle, it actually looks like it's almost a car with its headlights, two lights coming at us. And when we go back and look at that little star there and we zoom in, we can start to see those two stars separate. And that's what we call the two binary stars. And in fact, lots of stars in the nighttime sky are stars in multiple star systems, binary or trinary three or sometimes even more. And Alpha Centauri is cool because it is the closest star to us again besides our sun. It's 4.2 light years away. Meaning if you go outside right now and look at Alpha Centauri, it takes 4.2 years for that light to reach us. So if we're looking at it right now, that light left in May 2018. So it's taken that long, 2016 rather, May 2016. It's taken that long to reach us from that. So thinking back to May 2016, it seems like a lot simpler time, I know, given how 2020 is going. But it's a really remarkable thing that it's taken that long to reach us here on Earth. And in fact, when we look at it through the telescope, you can see that in fact, it is not one star but two stars. But near Alpha Centauri, so again, here is the Southern Cross. We have Alpha Centauri A and B. These are their kind of other names or technical names. Above it, if you look in the nighttime sky, there appears, it may look to you as a normal star or may just look as a dot or you may not even see it. But it's this smudge here. And it's smudgy because it's not a star at all. It's what we call Omega Centauri. Now Omega Centauri, so firstly just for these names, Alpha Centauri, the brightest object in a constellation is called Alpha. So that's Alpha Crux, the brightest in Crux, that's Alpha Centauri. And then we have Beta and then Delta, Gamma, so on. So Omega, thinking about the Greek letters, would be that fainter object compared to Alpha Centauri or Beta Centauri. And so this is one of the interesting things that we see is that it's this faint thing. And just because it's more relevant to what I asked, someone just asked, what size of telescope are we using to see some of these? So this is what we call, come from an eight inch telescope. So the telescope, all that matters is the size of the mirror. That's what determines really what you can see. The bigger the mirror, the better. But really at eight inches, you can see the detail of Saturn as I showed you. And this is also with a camera. In fact, it's better with your eye. Your eye is allowed to see a little bit more detail than it, than the camera I had set up. So you can see the rings even better. You can see the features of Jupiter even better. You can see these even clearer. And when we look at Omega Centauri through one of these telescopes, that's what we see. So this is an image taken through it. And so that little faint thing in the sky through this telescope, is this cluster of stars. It's this huge ball of stars. And there's literally millions of stars in Omega Centauri. It's a remarkable thing. And the thing is, it's what we call a globular cluster. So we have stars, we have galaxies. We have clusters of stars. And globular clusters are groups of older stars in these balls. In fact, we think Omega Centauri, this has been something that astronomers at Mount Stromlob have been studying for 50 years over that, is that we think that it could be the remnants of a dwarf galaxy. So we know that our Milky Way swallows in galaxies. In fact, right now it's nice and dark. If you look towards the south near the pointers, you will see that not too far from it, near the Southern Cross and the pointers, these two faint fuzzy things. You may be able to make it out. And sometimes if you're looking at it, your peripheral vision helps because you get to see more detail. And what these are are dwarf galaxies. These are called the large and small Magellanic Cloud. And we know our Milky Way pulls in these galaxies and they pull in these things. And so we think Omega Centauri may have been a dwarf galaxy that our Milky Way pulled in and ripped apart. And so this is kind of the remnant of our leftover bit of that galaxy. And so it's cool. We get to see all of this detail. We get to see millions of stars, millions of potential solar systems in this ball. One of the more interesting discoveries I think is that it appears that planets do not go or orbit around stars in globular clusters. And that is that there's something that hints at its age and how it's formed. And someone just asked, is it really a ball? Yeah, it is a spherical thing. It's not just a ring. It is a three-dimensional shape. It is a grouping of stars. And unlike some of the other stars we've seen this guy, these are kind of contained. These are near each other. Gravity's holding them around, spinning them around. And so people have mapped and kind of studied where the positions of these stars are relative to their depth, the way from us, how contained they are and to see it. And that's kind of what gives us this clue that Omega Centauri maybe was an old dwarf galaxy. Someone just asked, and I think that's a great point to point out is, I didn't talk about this, but we can use Alpha Centauri and the Southern Cross to find the South Celestial Pole. And there's two cool ways I'd like to show it. Firstly, is if we take the Southern Cross, we take the long part of the cross and we go one, two, three. That point there is what we call the South Celestial Pole. That is the point our Earth is rotating. In fact, if you look behind my head, all these stars are swirling around at that point. That is the South Celestial Pole. Our Earth is rotating at that point and spinning around. And so we can actually then say, all right, if that's the South Celestial Pole, straight down from there is South. The other way is if you draw a line through this part of the cross, you draw a line through the two pointers, that intersection is South. In fact, if you check, we have a previous video that I made on YouTube, you can check it out on Facebook to actually show how to find South. And it's a really cool way of seeing our Earth rotating, the exact point our Earth is rotating there. You can use it to find South. Once you know the South Celestial Pole, you can find South as well. And someone also asked, and this is related, does, do any of these stars have planets around it? We're finding lots of planets in our galaxy. We're finding lots of planets around other stars. Now Alpha Centauri, because it is close, has been something that's been interesting because if it's close, that means there's a better chance of studying it in more detail, could be brighter, easier to look at different wavelengths or different combinations of telescopes. And in fact, Proxima Centauri, that nearest star of the three, does have at least one planet, potentially a second. It has a planet that we know is about 1.18 times the mass of our Earth. So it's Earth-ish, not quite. The star is a little bit different, so it's not just saying it's like Earth, but it's a small planet. It has a very quick orbit a year. There's only, I think, a few days, maybe 18 days. And so it is a bit different than, say, the planets in our own solar system, but it, too, also has a planet. Now, besides Omega Centauri, there are some other things to see in our skies. Now, right now, we can't see this, but if you stay up till this morning, so let's say you're gonna be really dedicated this morning, now I mentioned earlier that if you stay up this morning and you look towards the west, or maybe you go to sleep and wake up at six a.m., you can do that as well. And if you look towards the west, you'll see Jupiter and Saturn. So right now, Jupiter and Saturn are in the east. You go outside right now, and if you wait till they move all across the sky, they'll go in the west. Well, if you're up at six a.m. as well, you will also notice a few things in the eastern sky. Firstly, we have Venus. So if you're waking up anywhere from 4.30, five o'clock, in the morning, maybe you're outside going for a walk, taking the dog for a walk, or something like that, hopefully you don't have to go to work that early. Maybe you do, there's a reward for you. And that is that bright object in the sky is Venus. So Venus sometimes has the name of the morning or evening star. In this case, it's the morning star because it appears in the morning before sunrise. And so Venus is super bright. Now, if you have a pair of binoculars or a small telescope like the ones we've been seeing, you can actually see that Venus has phases. So just as the moon, the moon has phases, sometimes a quarter moon or crescent moon, sometimes half, sometimes full. Right now, it's about two days from new moon. You can also see that with Venus. And we talked about both Adam and I that Galileo used the moons of Jupiter and actually showed that the sun, not the earth, was the center of the solar system. He also used Venus because Venus has phases that shows that it's orbiting around the sun rather than the earth, and therefore was a very critical part of evidence to show that the earth was not the center of the solar system. And so have a look, and Venus will be out for quite a few weeks in the morning sky, but right now we can also see Mercury. Mercury is a lot smaller down there, but it is visible. Now, Mercury, you won't be able to see probably too much detail on it other than seeing that it's a nice point of light. But if we're looking near Venus and Mercury, and I'll explain about the moon in a minute, you'll also notice the constellation Orion. Orion is just rising in the morning, and there's a few cool things in Orion that I love. There's Betelgeuse. Betelgeuse was kind of in the news a while ago that it was acting funny and maybe it was exploding. Now, Betelgeuse is due to blow up any day. I work on exploding stars. I love stars that blow up. It makes me happy. Luckily, our sun will not blow up, so that makes me even safer. But Betelgeuse will blow up at some point, maybe 10, 20,000 years, but this year was not gonna be it. I know in retrospect, maybe it could have been, but Betelgeuse is also what we call a red supergiant, so it has dust and other things around it that sometimes block our light. But what I really wanted to pay attention to is if you look in the Orion's belt, those three stars, now, sometimes in the Southern Hemisphere, we call this the saucepan, the handle going down to the pan. Well, the middle part of the handle is actually Orion's nebula. And this, again, is a photo to the telescope of Orion's nebula. You can see all of this gas, and so the colors actually relate to different elements, different gas, and that is evidence of what left that star, the gas that's left that star. And you can see that it has this fuzzy, milky way. And even though when we look at Orion, it just kind of looks like a dot. That handle is like a dot. When we use it through a telescope, we can see a whole nother world going on in Orion's nebula. So that's something else to check out in the early morning. And the reason I wanted to point out the early morning is there's something really unique happening on Sunday morning. Sunday morning, about 6 a.m. Again, this is all viewed from the Southern Hemisphere, but all the planets are visible in the Northern Hemisphere as well. So for the next three weeks, we'll be able to see five planets in the sky as we described, Jupiter, Saturn, in the West, Mars, trying to straight above you, and rising in the East, Venus, and Mercury. Now, as I said, we can't see that for a few weeks. Now, what's kind of cool is that's the most planets we can see with our eyes. Now, we have eight planets. We cannot see Uranus and Neptune with the naked eye. It is just too faint. Now, you could say we can see six planets because we can see the Earth, but we kind of ignore that one. Not that it's not special, but it's never... We always can see it in our skies. So of the five planets that we can see with our eye, all five are visible in July. Now, you can see Jupiter and Saturn all throughout the night, as I said, Mars after evening and midnight. But if you wake up around 6 a.m., 5.30, you can see Jupiter, Saturn, Mars, Venus, and Mercury. And if you wake up Sunday morning, 6 a.m. in particular, you'll also have the moon. So you'll have Mercury, the moon, Venus, Mars, Saturn, and Jupiter. It doesn't really get much better in terms of stargazing than that. So if you can spare waking up a bit early on your Sunday morning, it will definitely be worth the while to go out and see these things. You can see all of them at the same time in our nighttime sky, which is a really special thing to be able to see. And we don't see the planets all five of them all the time. And if you remember, we were talking about opposition. We need all of those planets to kind of be on the same side of the solar system. The last time that happened was in 2018. So it's not super rare, but it doesn't happen every year. And so it's definitely a great chance to go outside and take a look. And while we want to connect with the stars, as Noeli said, and we all can connect with the stars, we can all connect with the planets as well. And I think, so don't miss out on it. Take the chance of seeing it. And as I said, you can see some of that. Those moons of Jupiter, the rings of Saturn, Mars. Mars looks like a red dot. I'm not going to try and lie. Mars looks like a really bright red dot, but it's still cool. It's the planet Mars. Venus, you can check out the phases and you can see Mercury, which is usually hard to see. So there's a question, is the moon still around with Monday morning? No, the new moon will happen Monday. So we won't see it in the morning sky. So if you want to see the moon plus the five planets, it is this Sunday morning and you pretty much need to do it at six a.m. This is a graphic of how it'll look exactly at six a.m. So you'll see Mercury kind of right next to the moon, Venus, Mars, Saturn and Jupiter. If you wait till Monday, it will be too late unfortunately, but you'll still be able to see five planets. That's still fine. That's still good. And you'll be able to see those five planets for the next few weeks. Now there's something else I just wanted to note before we do a few more questions and end for the night. And that is Comet Neowise. Comet Neowise is kind of making the rounds is a really big story. Now, if you've heard of Haley's Comet, maybe you saw Haley's Comet or maybe you're waiting another 78 years or till 2078 to see Haley's Comet again. I am. There's another bright comet visible with the naked eye. Now this is the photo of it, but people all across the Northern Hemisphere are reporting images or photos of comet Neowise. Now just for, it's always nice to explain, the way we get these comets named is the official name is C, 2020, so that's the year it's discovered, F. So we kind of divide that each planet is half a letter. So or each month is half a letter rather, sorry. So A is the first half of January, B second half, C, D, February, E, F, March. So this was discovered in March and it's the number three. And as it's been discovered, this name Neowise, that was the satellite discovered. So the cool thing is, if you discover a comet, it has to be named after you. And so most of these projects, because it's a survey and a group and a collaboration of people, it's named after the project Neowise. Now, Neowise is lighting up the skies, as I said, in the Northern Hemisphere. And I think this photo is super amazing because you see two tails. Now there's two tails for a very important reason. The first tail, this is the gas melting off the comet. As the sun's going around, the comet's melting it and the solar wind as it's called is blowing that comet and we're seeing that beautiful tail. The blue one is what we call the iron tail. These are things being spat off or pushed off from the magnetism of the sun blown off into space. And you notice it's in a direct, they're in two different directions. And that is one is following the direction of the comet. One is relative also to the position of the sun. So it's really unique chance to see both of these tails. Now, you may be asking, hey, I live in the Southern Hemisphere, when do I get to see this? I know I'm asking that question. And I know lots of people, even Adam was asking this question, where can we see it? Or when do we, can we see it? Now, as Adam knows, we can't quite see it yet. It is not visible in the Southern Hemisphere. It is only visible in the Northern Hemisphere. But fear not, that may change. If the comet survives for another couple of weeks, so right now this is kind of its progress through the solar system. It's moving through the stars. Now we can't see the Big Dipper. These are in the Northern Hemisphere. But you notice it's approaching and it's kind of going towards the south. In fact, you may know the constellation Leo. We can't see Leo at times here. And in fact, potentially by the 30th of July, it may be far enough south, and it should be far enough south, that we can see it in the early evening, around 6 p.m. here in the Australian skies. Now there's a couple caveats to that. Comets are like cats. You never know what they're really gonna do. They do have tails, but you know sometimes they just don't like you. And with this comet in particular, we don't really know if it's gonna survive its trip around the sun. It may start to go around the sun. It may melt too fast and break apart and disintegrate. Too much of it may melt, and it made me too faint to see with the naked eye. There's lots of things that are hard to predict about this comet. But if it goes according to plan, as best as we can hope, and if it continues at the way that it's going, we may be able to see it with the naked eye in the southern sky. So kind of we need to wait about two weeks until we know if we can see comet Neo-wise here in the south. And if we can, it will be spectacular. If you live in the northern hemisphere, go outside and see it. What are you doing? No, seriously, but go outside and see it. You can see it in the early evening, right in the early morning, rather in the northern hemisphere all across. I've seen photos of it from New York, so you can see it. And you know, we don't get comets visible with the naked eye all that often. So definitely take a chance at seeing it. And you know, you may be able to see something very special. Now we'll take a few comments or a few questions before we end. Again, we are sorry about all the spam links that were posted in the event. We will never ask you for your critical details. We are sorry for, you know, it was very disruptive, we know for all of it. Thank you for bearing with us. We've made a few changes to the comments, so we know that may have locked out some of your comments and questions. We apologize. If you do have a comment or question that we haven't been able to answer, send us a message, either Mount Strom or Facebook page, Dr. Brad Tucker in the events, whatever, and we'll try and answer it, you know, tonight or tomorrow so you don't miss out. We do apologize that it, you know, what it did. You know, unfortunately, we know that some people have nothing better to do. But we know there's things in the sky that are much better to deal with. And someone has actually asked, what kind of telescope is best to see the moon and stars? And this is a great question. You know, you're enjoying these nights, what can you do to see it? And as he said, it's all about the size of the mirror. Now, my favorite telescope is called a Dobsonian. That's the type of telescope. It's a long tube. And in fact, that's the one I've used for a lot of these photos and videos. And so it's a long tube and it's pretty portable. It's also kid-hardy, so it's hard to break. You can break it, it's just hard to. And they come in four and six and eight inch in sizes and they're relatively modest and cheap. Now, the negative of a Dobsonian is it doesn't move with the sky automatically. So you have to keep moving it. But the cost is always with moving things in the sky. So if you want a nice, simple to use telescope with your family to go outside and see all the amazing things we've talked about and more, go a Dobsonian. It tells you how to point things in the sky, how to use it, and they're also quite affordable. My advice is always to buy online. A, for sometimes obvious reasons, if you can't go into the shops as much right now, but online you'll get a better deal and there's great companies, especially in Australia that are willing to help you, give you advice and answer all your questions as well. So a Dobsonian is a very great chance to do it. And so someone asked, and I said, I'd like to do exploding stars. It's exploding stars, but it's commonly known as a falling star. No, an exploding star is what we call a supernova. These are just stars that explode. Supernovas are really bright stars that release all of their energy and explosion. Now the cool thing about exploding stars is stars explode, 50 stars explode every second. So we're about to end in a few minutes and our public night would be an hour and a half. So that means 240,000 stars have exploded since we started this night. 240,000 solar systems have exploded. Now a falling star, sometimes called a shooting star, is actually a meteorite. So this is a bit of rock from an asteroid or something like that that has broken off and burning in our sky. Some people may have seen in around Sydney, New South Wales, we saw it even in Canberra earlier this week of bright fireball passing over the skies, that was a meteorite. So they're not really related to stars even though we say they're stars, they're just giant chunks of rock burning in the sky. Now there was a few other previous questions before, will a storm on Jupiter ever stop? We think it may stop. The first measurement of the Great Red Spot in Jupiter was about in 1880s and it was estimated to be about five times the width of the earth. Now it's a little bit less than three times the width of earth and there's some predictions that eventually it will stop and then go away and disappear. And one of the cool things is Neptune, Neptune had the great dark spot and the great dark spot was a storm system we think like the Great Red Spot of Jupiter and that's actually been confirmed to have disappeared that we actually saw it disappear. Someone's asked a great question, what would happen if an asteroid hit Jupiter? We actually saw in 1994 Comet Shoemaker-Levy-9 smash into Jupiter. So there were some telescopes and images taken from sighting spring observatory our dark facility in Northern New South Wales in Cunabariburon, which is one of the world's best places for astronomy. We have it here in Australia. That saw a comet slam into Jupiter and when it did it created a hole 12,000 kilometers wide. That's about the size of the earth. That's a pretty big hole. And so that's kind of a really interesting impact that we saw early times with the comet impacting Jupiter. So we kind of know potentially what would happen. We do think that it may stop at some point, but it's kind of a cool thing that kind of cool thing that these things do happen in real times. We don't necessarily think that they happen, but they do happen at the same time. They do happen in real times. So here's another great question that's important. Why don't we see the same things in the Northern sky as the Southern Hemisphere? So I'm just gonna stop sharing here because it may be easier to show with my hands. So we have a, we're a ball, right? Our earth is a ball. And imagine we're standing on the bottom of the ball here. Well, we can look side to side. We can look down, but we can't look up because if we're looking up, we're looking through the earth. So you can see in theory, 180 degrees. If you imagine 360 degrees a circle, we can see 180 degrees at most. It's actually a little bit less than that in practical terms. And so when we look around, we can't kind of see up because the earth is blocking it. So that means we cannot see the stars in the Northern Hemisphere. The people in the Northern Hemisphere can't see the stars in the Southern Hemisphere. But sometimes we can see some of the same stars and that is the ones along the equator, right? We can both see to the equator from the North and the South and we see similar stars. And one of the interesting things about the planets, for instance, our solar system is a giant disk. And that means we can all see that disk because we're all part of it. Just as we can all see the sun, we can all see the moon, we can all see the planet. So we're all seeing the planets at the same time, relatively speaking to where you are. So that's kind of why it's because of that nice big earthy globe that we live on. So someone's asked, I work on supernova, how long will it take till the sun explodes? The sun will not explode. The sun is too small to explode. We know that the sun will eventually puff out. It will swallow or at some point it will swallow up Mercury. That's okay, as Adam said, we don't care. It will start to heat up Venus and then it'll eventually get close to the earth. Now this is not for billions of years. We do not have to worry about it. And it's a great problem we don't have to worry about. But we do know the sun will evolve and change, but just on huge time scales that we really don't have to worry about. I know we're running a couple of, we're getting it. We'll do a couple of last questions. Is there any substance in the headline that the mysterious planet nine is being a black hole? So for those who don't know, there's a theory that says that there is maybe a ninth planet. Again, we're not talking about Pluto. We're talking about another thing on the edge of our solar system where it's so far out one year is 30,000 earth years. There's a couple of theories. One could say that it's a massive planet four to 10 times the massive earth, the super earth, as Adam had talked about a bit ago, could be a bunch of smaller dwarf planets or trans Newtonian objects that make up that mass. We don't know what's causing the things that we're seeing out there. We see orbits of dwarf planets that we can't explain properly. And so there may be something else out there. So some people say, hey, maybe there's a black hole out there. A black hole really doesn't fit the bill. So yes, the black hole through its gravity would change things. It doesn't really explain all of the pieces of evidence that we have in terms of what existed. And it just doesn't make sense that it would exist. So it's one of those things that if we exist all the possibilities and we can determine it's nothing's there or whatever, then you would have to look at other alternatives. But a black hole would also give other signs of existing out there that we don't see. And so it kind of just makes the headline, but it probably isn't the case that there is that that can explain planet nine. So I hope that answers your question. Someone actually has quite an interesting question. How do radio signals reach us in Voyager when we can't even getting a phone signal from the next suburb? That is actually a really great question. And there's two parts of the answer. And that is your receiver and your antenna. Now for Voyager, it has a superpower for antenna way bigger than your phone. So it can broadcast huge signals, but also it's not transmitting as much data. It takes a long time to download the data. So, you know, talk about sometimes you have a slow internet connection and it takes hours to stream it. So I hope no one has too bad of an internet connection watching this video right now. You may have experienced that. Voyager does have that. It takes a long time to download the data. Now, the great thing we though have also about Voyager is the receiver, the antenna is gigantic. Outside of Canberra, just 20 minutes past Mount Strom observatory is the tidbobilla tracking station. And they have a radio receiver 70 meters wide. It's essentially a big bucket to collect radio waves. Just as the bigger telescope allows us to see faint or light and therefore we can see more detail, so does a radio telescope. So if you pointed your mobile phone at it, you would hear lots of signal. In fact, if you go to places like this, they tell you to turn off your phone because that signal in your phone will actually interrupt the very small specific detailed observations they make and can ruin some of the data they're taking from it. Because in fact, you're in radio antenna or your mobile phone antenna is way stronger than that. So sometimes that's always fun, but that's the way it goes. There's also other practical things that sometimes the infrastructure is not good, so I apologize for that. But it also shows the marvel of technology that some of these satellites are built at. As you said, to transmit signals, literally billions of kilometers across the solar system to be picked up and talked about. Thank you everyone for tuning in. Again, we are sorry for the spammers. We will do better next time. We do hope you enjoy your time. We hope you had fun. A couple other things. There is a talk on star clusters. Talked about Omega Centauri on August 6th by Wei Shen. Our next public night will be on the 21st of August. We'll do some different stargazing. We have some different talks planned up that should be fantastic. It's during science week. And if you live in the Northern Territory, the ACT you may have seen, we're doing satellite selfie. Stay tuned, there are more details, but keep your science week free on the 17th of the 21st of August because we have lots of cool things planned. And you can literally take a selfie from a satellite. You've got to watch for more details. Take care.