 Okay, I'm going to start the I'm going to click the go live. Yeah, we got a battle here and then we'll get started. Yeah, the classic automatic except you have to push this button setting, which you can actually adjust that setting so it is just pure automatic but always where I'm going to accidentally stream the wrong stream to the wrong YouTube channel if I do that. And Dave, I don't know whether you meant to put the live stream link just for the just for us because because some of my click it and accidentally get a weird echo. Yeah, we don't want that. No, I'm not. Yeah. Well, they don't need to see the live stream. So, exactly. Yeah, we wanted to send something to Colby's family so they could check him out too. Well, let's go ahead and get started here and so hello everyone and welcome to the April NASA night sky network member webinar we're hosting tonight's webinar from the astronomical society at the Pacific in San Francisco, California. We're very excited to present this webinar with our guest speaker Colby Osberg from the University of California at Riverside. Welcome to everyone joining us on the live stream on YouTube we're very happy to have you with us. These webinars are monthly events for members of the night sky network. And for more information about the night sky network and the astronomical society the Pacific and just a moment we'll put a couple of links in the chat. But before we introduce Colby here's Dave prosper with just a couple of announcements. Okay, hi folks. Right off, I just want to thank you all for joining us today. And my apologies if you're watching this on a recording that you did not get my reminder email spent most of today trying to get our system to send everyone a reminder and obviously it didn't work in time. But thankfully it's a bug that only affects super users like myself and coordinators you're fine club members you're fine. And my apologies again, let me fix. And more fun news, we're going to be at the ncrl vision 2022 the convention for the north central regional astronomical leagues convention convention, this May 13 and 14. So if you knew the port Washington, Wisconsin area, and for those of you not near that area it's also near the greater Milwaukee area. So stop on by and say hi. There's going to be a ton of great speakers and great company there and I'm going to put the link in the chat. And I've been calling it ncrl. I don't know if that's correct. I'll find out soon enough. It's also global astronomy month organized by the good folks at us at astronomers without borders. They have tons of different events that have gone on already and there's even a few more going on as April's astronomy month comes to a close. So if you want to find events on their site at astronomers without borders.org and the link will also of course be in the chat. Now, this is related the globe at night's light pollution measurement campaign is on this week. So take a look at Leo and use their charts to determine the quality of skies where you're at, and report back to globe at night if you have their pop and details around their website which is globe at night.org and that link is in the chat and also extremely related to the previous two it's also dark international dark sky week from the International Dark Sky Association, and you can find out more about light pollution in ways we can mitigate or eliminate it all together on their site and for their events are also having this week. If you've never seen a sky from a dark site, especially the Milky Way from a dark sky park, it's worth it if you get there. And for more info, go to ID SW dot dark sky dot org and where is that link and also be the chat. And that's pretty much it but I just have to add, if you wake up early tomorrow, you got a clear view of the eastern skies and there's that line of planets going on. Looks great. It's going to be a special guest the crescent moon. It's hanging low below Venus tonight's subject. So, yeah. So I'm Saturn somewhere off to the side there, a little ways away from Mars, and that is courtesy Earth Sky and John Goss so I just thought of Venus, check it out. That's it for me. Thanks, Dave. I also want to mention that it's never too early to start planning for total solar eclipses we are under two years from the 2024 total eclipse and about a year and a half from the annual eclipse and I hope Vivian might give a little mention about the program that we're doing and hopefully she can find the link for you can sign up to get more information at some point. So Vivian, do you got anything to say? Oh, a little teaser. We're really excited. We just got funded to lead a project called Eclipse Ambassadors off the path. So if you are from somewhere that's not on the path of totality or annularity coming up, or even if you are and might not be there for the eclipses we encourage you will you'll get plenty of information from us soon to sign up to become an eclipse ambassador I'll stick that in the chat in just a minute. We'll partner amateur astronomers and undergraduate students to prepare their communities in advance of the eclipses. We're really really excited to have you participate and we'll get you plenty of information in no time flat. Thank you Vivian. So for those of you on zoom you can find the chat window and the Q&A window, generally at the bottom edge of the zoom window on your desktop, please feel free to greet each other in the chat window or to let us know if you're having any technical difficulties please send us an email at night sky info at astro society.org. If you have a question you would like our guest speaker to answer, please type it into the Q&A window, and we'll keep the chat for just chatting, and also speaking of the chat, make sure that you select everyone, and because of defaults to just host and panelists. I'm going to hit the record here for the welcome to the April webinar of the NASA night sky network this month we welcome Kobe Osberg to our webinar. Kobe is currently a fourth year PhD student at the University of California Riverside. He received his BS in physics at San Francisco State University before joining Dr. Stephen Cain at UCR. Since his arrival there he's been immersed in studying all things Venus. They published a paper in 2019 which predicted the number of potential exovenuses that the trust your exoplanet survey satellite, otherwise known as tests would discover. Since then he's focused his attention on the transmission spectra of exovenuses which will allow the opportunity to estimate the atmospheric composition of these planets. Please welcome Kobe Osberg. Thank you for that wonderful introduction. I guess I can go ahead and share my screen. Cool. Looks great. Awesome. And let me just get set up with the presenter of you. Okay. So, again, thank you for having me here to preach the Venus gospel. I'm very excited. I have been studying Venus for quite a while now. And I love being able to, you know, tell people how cool it is because it is typically portrayed as not being cool at all. So, let's just go ahead and get into it. Of course, before I start a little bit about me, you already mentioned some of this, but I'm a fourth year PhD student at Riverside. And I did my undergrad at SF State, which is pretty close to where your community is based. So that is awesome. I'm in San Francisco and I miss it there. It's definitely not as cool down here in Riverside. Not really much going on just a lot of deserts and sweltering heat, which is soon coming as we are near the summer. But yeah, so I did my undergrad in physics and I definitely enjoyed it. But I just came to the understanding that the amount of math that you had to do to actually have a career in physics was just too much for me. I was talking to a lot of graduate students who were doing like their masters at SF State while I was there and just seeing the things that they had to do for their masters in physics. It just sounded awful. And Stephen Cain, which is my current advisor, was actually a professor at SF State and I took an exoplanets course with him. After taking that course, I realized that exoplanets are amazing and I decided to pursue it. That's why I'm here now. So I'm very lucky that he was there at SF State. And so since I've gotten here, I've pretty much been doing all things Venus. As Brian mentioned, I published a paper with Stephen Cain and it was either 2020 or 2019. I honestly do not remember. But that paper just focused on predicting the amount of exovenus exovenuses that the test mission would be discovering throughout its lifetime. And I did a little stint with Sue Smirkar at JPL and she is amazing. She is the, I think the deputy PI on the Mars insight mission and I think the lead PI on one of the new Venus missions, Veritas. And so when I was with her at JPL, we were doing a lot of Venus geology. And I'll talk a little bit more about that later. So I've been doing, you know, exovenuses and also Venus here and the geology aspect of it. So I've been really just trying to round out my skill set and the things that I know about Venus. Since the paper that I put out, I've been focusing mainly on transmission spectrum, which is basically the main tool that we will have for determining the composition of the atmospheres of exoplanets. And I'll go into more detail about that as well. For those that are not aware, let me just go over some of the cool facts about Venus. So Venus is extremely hot. And this is one of the reasons that people tend to ignore it's just because, you know, oh, it's way too hot for life to exist on the surface, therefore, we should not care about it for that is wrong. We should definitely care about it. And so one cool fact about the surface temperature is that if you were to take a frozen pizza out while you were on the surface of Venus, the pizza would cook in 10 seconds, because it is that hot. So if you ever need to quickly cook a pizza because of an emergency, then the best thing to do is to take your pizza to Venus. Besides the extremely hot temperatures, it only gets worse. There's also an extremely high amount of surface pressure, which is mainly due to the extremely thick atmosphere. And so just to. So the surface pressure is 92 bars and just to put that into perspective, you know, here on earth, we are at one bar at the surface. So 92 bars would be the equivalent of going almost a kilometer deep into the ocean. So the weight of the ocean and the atmosphere on top of you, when you're 900 meters deep is the same as being on the surface of Venus. So that doesn't sound like a good time. Venus is completely covered in clouds. So you know here on earth clouds are variable and you know they're never covering the entire planet at once on a Venus that is not the case. And so this is why Venus is able to stay so hot because of the greenhouse effect that occurs. And so those clouds are composed of mainly sulfuric acid and water. And so not only would you be crushed by the atmosphere and pretty much melted by the high temperatures you would also be dissolved by the acid that consists or that is in the atmosphere. So it's just not not a good time on the surface of Venus. Venus is also kind of weird just because it is rotating in the opposite direction of all the other planets other than Uranus, of course, which is on its axis, and it rotates very very slowly. The rotation is almost the same as its orbital period, so it is almost will be called tidally locked. And yeah, so this is weird and there's some speculation as to this speculation that this rotation rate is responsible for the environments that we see today. So weird thing is that, or I guess not weird, but in the past when we couldn't see through the atmosphere or know what's going on in the surface of Venus, we believed that it was actually a swamp planet. And there is a bunch of old science fiction movies that are pretty terrible, but cool nonetheless, that depicts going to Venus and seeing like dinosaurs walking on its surface and things like that. But once we were able to actually, you know, see the temperature of the atmosphere and down to the surface then we realized that okay well it's not a troubled planet. And so why should you care about Venus as I explained it is pretty terrible, not for us, but it is a very very interesting planets. One of the reasons that it is particularly interesting is that work has been done recently that showed that Venus could have had a extended period of having temperate surface temperatures. And if anyone's interested the paper is by Michael way and 2020 and basically with the with the right starting conditions when the planet forms. It could have, you know, sustained a livable climate for up to a billion years ago. And of course there's factors, a bunch of factors that, you know, could affect whether it would have had water in the beginning to help sustain that temperature or not, but the model that Michael way ran show that it is possible. Not know for sure and it'll be very difficult to actually determine that it was habitable but the possibility of it is very very intriguing. Another thing that people tend to forget is that Venus is the most physically similar planets are Mars is the one that gets all the attention by NASA and other agencies it gets all rovers all latest technology and Venus doesn't get squat. But it shouldn't just get squat because it is extremely similar to Earth. It has 90% radius that is 90% that of the Earth's radius, and its mass is about 85% that of Earth, whereas Mars is very very small. And so the fact they're so similar makes it even more intriguing as to why are they so different now. This is why Venus is very important in the search for life in the universe and understanding how planets become habitable is because you know what what happened to it. If it was similar or since it is similar to Earth. You know what exactly was the tipping point that caused it to diverge from Earth's evolution so drastically. And these are things that are currently being looked into and things that the new missions, which I mentioned down below will really help us investigate. And so the new missions that have are being planted or they have been accepted by NASA are the Da Vinci and Veritas missions. And there's also a sequel to the venera spacecrafts that were sent to Venus a long time ago by the Russians and that is called venera D. And there's also a ESA, which is the European Space Agency. They are also sending a mission to Venus. And so Venus is becoming pretty popular, which is fantastic. And these new missions will be, you know, extremely helpful for understanding what happened to it. And of course there's a lot that we still don't know. And I'll get into that, of course. So just a little breakdown of, you know, what we have sent to Venus from Earth. Probably the most famous missions have been the venera missions. And that is primarily because they were able to take pictures of the surface. But there is also, you know, mariner, pioneer Venus, Magellan, which is, which I'm going to decent amounts. And the latest ones were Venus Express and Akatsuki, which is a Japanese Space Agency mission. But since Akatsuki, Venus has received nothing except for loneliness and neglect. And you know, it's quite sad. But with these new missions, we will definitely be spoiling it. And hopefully it'll make up for all the last time that we were not investigating it. So just to go a little bit more in depth about some of the missions that I mentioned. So the venera missions were, I think there was like 12 or 13 of them were spacecraft that were sent to Venus by the Russians. And the venera three was actually the first human object to reach another planet's surface, which was awesome. And it was actually the first to take a picture of another planet's surface from the surface. So a pretty, you know, benchmark mission and honest descent was able to take measurements of the pressure and temperature on Venus, as well as things like wind speeds. There's a funny little anecdote. So I don't remember which of the 12 or 13 venera missions it was. But on one of these spacecrafts, they had a device that was designed to measure the compressibility of Venus' surface. And from those measurements, I think they can determine like the composition of the surface and how dense it is, things like that. And they also had a camera to take pictures. And so the camera needs to be protected as it is descending. And so they have a cap that goes over the camera. And so the cap needs to be ejected and with force because the atmosphere is so thick that it, you know, it takes a lot of force to actually move things. And so it ejected properly, but it happened to land directly under the spot where the device was going to measure the compressibility. And so the device sent back data and it returned the compressibility of the lens cap instead of Venus' surface. I'm sure that was extremely frustrating for people who spent years of their life, you know, deciding this mission, but, you know, it's hard to make sure everything goes correct when you are, you know, having things happen on a different planet. This was a pioneer which was able to measure the composition and temperature of the upper atmosphere, as well as the plasma environment and the ionosphere of Venus. And it consisted of a orbiter and four probes that were able to, again, measure important things like the composition of the clouds and the pressure and temperature deeper into the atmosphere. And it's really cool. I don't know if it was from the same era or not, but it's really cool like poster for pioneer and I really, really love this photo. Now for Magellan, and so I used basically only Magellan data when I was working with Sue Smirkar. And so Magellan was an orbiter that did a fantastic job of taking images of the surface, as well as measuring the topography or just like the height of different geological features on Venus. And to this day, I guess, you may wonder, you know, why am I using this 30 plus year old data to study Venus' surface? Well, it's because that's all we have. There has not been any updates to this data that we got from Magellan. And so, you know, it was a 30 or the mission was 30 plus years ago. And so therefore the devices used to get the data were also 30 plus years old. And so that means the resolution of the measurements that it took was not very good in comparison to today's standards. And so just to put it in perspective, if you were to map Earth's surface with the Magellan orbiter, you would not be able to resolve the San Andreas fault because the resolution is that bad. And that is a important detail to miss because the San Andreas fault is a clear indicator that there are tectonic plates on Earth. And so with the new missions, I believe Veritas is going to be redoing this thing that Magellan did. With the new data, you know, there could be a lot of stuff that we discovered that we just missed out on because of how bad the resolution was. But I know I was hating on it a lot, but we still learned a lot from this mission. There is possible evidence of subduction on Venus's surface. So in that top right figure, we're looking at the topography of a feature called a corona on Venus. So red is indicating higher topography and green is lower topography. And so there is like this trench around this corona and the coronas are just like circular features that are all over Venus's surface. And so the trench on the outside is potentially where a part of the crust went underneath a different part of the crust, which is essentially what subduction is. And so that is really, really, or if that is actually subduction, then that can help us understand a lot about Venus's history because on Earth, subduction is vital for recycling carbon from the atmosphere back into the interior. So subduction allows us to keep our carbon levels, you know, relatively low. And that's why, you know, global warming is or climate change is the thing because we are speeding up that process of putting that CO2 back into the atmosphere. And so the subduction is not quick enough to account for how much we're putting out. I guess, lastly, another thing that Magellan discovered is that there are very few craters on the surface of Venus. And so we use craters or the number of craters on the surface of a planet or moon to date the age of its surface. And so when we dated the age of Venus's surface, the crater showed that the surface is around a billion years old, which doesn't really make too much sense. There isn't really any erosion going on of Venus's surface. And so the hypothesis that was used to account for this is that there was a catastrophic resurfacing event where a billion years ago the entire surface was covered in lava, which then, you know, covered up the craters that we should be seeing to because the crater should, you know, reflect that the planet is four billion years old or whatever. And so the theory is really dramatic. And it is only a, or I guess it would be a hypothesis. It is only a hypothesis. And there are other, you know, different things that have been brought up that could answer the same question, but the catastrophic resurfacing is accepted by some of the community. But it sounds really crazy. It would have been crazy to witness. And lastly, let's talk a little bit about Akatsuki. So this was a Japanese Space Agency mission. And honestly, I don't know too much about the science that they have done. I know that it has a strong emphasis on setting the clouds on Venus. And so this is one of the cooler features that they have found. And so you can see this like bulge in the middle of Venus here. And so that is essentially a gravity wave that is traveling through the atmosphere and creating this crazy bulge that we see here. And the scale of this is crazy. It's like, it's like 6000 miles wide or something. I guess that would be vertically. And so yeah, so it was like really crazy things going on in the atmosphere on Venus that we would not be used to here on Earth. And another thing that Akatsuki has become famous for is it's really amazing photos of Venus. So these aren't in the visible spectrum. So if you were in space looking at Venus, it wouldn't look quite like this. They are using filters to look at different structures of the cloud. So it's either in like the ultraviolet or in infrared that you're seeing this. But these are really, really awesome photos that they have of Venus. So despite all these missions, there are still a ton of things that we just do not know about Venus. So just a list of few. We don't really know what the structure of the interior is, you know, here on Earth. We have, you know, the core mantle and the crust, but we don't know if that's the same on Venus as well as what it is composed of. And the interior is very important because the interior of planets is what generates a magnetic field. On Earth, the magnetic field is very important for deflecting solar wind and protecting our atmosphere. And Venus does not have a magnetic field. So we would like to know if it did in the past. And so learning more about the interior would help with that. Plate tectonics, as I mentioned, super, super important for recycling carbon. In the moment, we say that Venus has a stagnant lid. And so that is basically the crust is one thick or one complete plate. Whereas on Earth, you know, we have plates that are moving tectonic plates. And so the thing the possible signs of subduction kind of hint to, you know, there might be some form of tectonics on Venus, but we really do not know. And also the water loss history, we would like to know whether Venus have water or not. And the D to H so that is D for deuterium and H for hydrogen so it's the deuterium to hydrogen ratio. And basically the ratio of the those two elements in the atmosphere can help us understand how much water did Venus have in the past. We don't really have any good measurements on that because all the measurements of that were taken by the older missions, and the uncertainties are very high so we can't really learn too much from them in the moment. Was Venus habitable in the past, if it was how long was the habitable and what caused it to be completely uninhabitable to life as we know it today. So the ways that we are going about trying to solve these mysteries is either through in situ missions so missions that go to Venus and take data from the planet itself, or which I will be talking mostly about today the study of exoplanets. And so the in situ missions, as I mentioned before there's four new missions that are coming out. And that will ask, they'll help answer you know some of the direct questions about Venus that we have. Whereas the study of exoplanets is kind of like a indirect pathway to to learning about Venus. So we are interested in planets and this is primarily what I have been working on is planets that are in the Venus zone, which I will be defining in a couple slides. And so when we discover a planets that might be Venus like the way we can learn about those planets is by observing their atmospheres through different techniques that again I will define later. So these planets are really important for understanding Venus, even though they may not be exactly like Venus because we want to try and whittle down what were the main causes that made Venus the latest today. And so Venus receives a lot more energy from the sun than we do. So that is one potential factor. And so what we could do is find a rocky planets that receives a similar amount of energy from its star that Venus does, which I think is around two times amount that Earth receives. So we find a planet that's two times amount of flux in the earth. And if we find that, you know, that planet may be able to sustain a habitable atmosphere if we find that it has, you know, water, then, you know, it helps it bodes well for the theory that Venus could have been habitable in the past. And so we can use exoplanets to basically confirm things that we are wondering about Venus here. Alright, so let's get into how exactly we discover exoplanets. So the main method that is used today to discover exoplanets is called the transit method or transit detection. And so with this method, basically what we are doing is looking at a star. And we are basically this have if you don't know that there's a planet there, they'll just point a telescope at a star. And if, while it is looking at the star we see the brightness of that star drop that we know that something is passing in front of it. And based on how much that brightness drops the amount that it drops, we can then determine what the size of the planet is in comparison to the star. And since, you know, there is like a limit on how small of things that we can detect. There is this method is more sensitive towards larger planets, but it also helps with the star is a lot smaller. And so a lot of the missions recently like tests and Kepler, which I hope some of you all have heard about. They have been using this technique and they've been looking at a lot of really small stars and they've been finding a lot of rocky planets, rocky planets, transiting in front of their stars. This method is also more sensitive to planets with shorter orbital periods. So our solar system is very weird because it is very spread out. But when we are looking at a lot of cooler stars, the systems around those stars tend to be a lot more compact and have a lot shorter orbital periods. And the reason that it is more sensitive to these shorter orbital periods is mainly because the chances of actually detecting or seeing the thing the planet pass in front of the stars a lot higher because it passes in front of the star more often. And so if you were to try and look at, let's say like the earth. If we were looking at a completely analogous system to ours, we would only see the earth transit once every 365 days. And so the chances of actually seeing it transits when you are looking at the star is very, very low. So as I mentioned, this method is used primarily by the test mission. And so test stands for Transiting Exoplanet Survey Satellites. And this mission was launched in 2018. And it has basically been surveying the entire sky and seeing if planets are transiting in front of stars. And it has been doing a very, very good job. In particular, it has been finding a lot of planets that are in the Venus zone, which I will explain in the next slide. And one thing that is great about tests is that it is observing stars that are nearby and therefore a lot more are very bright. And the mission that tests was the predecessor, I don't know if predecessor is the right word, the mission that came before tests was called Kepler. And it did a similar thing. It stared at a single point of the sky looking for transiting planets, but the stars it was looking at were very far away and therefore very faint. And it is easier to learn about exoplanets when they are around a brighter star. So it is very good that tests is looking at nearby stars. And yeah, so let me explain the Venus zone. So the Venus zone is basically a first order S or we use it as a first order estimates to determine whether a planet is Venus like. And so this is a very busy plot. So let me just try and explain it. On the y axis is the effective temperature of the star. I believe the sun is around like 57, 5700 degrees Kelvin. So it would be, you know, in the middle and you see Venus Earth and Mars here. And on the x axis is the percentage of star lights that the planet is receiving relative to earth. And this is a log scale on the bottom. And so you can see earth here is at 100% on the x axis and the y axis is the temperature for the for the sun. But these shaded regions here the red is the Venus zone and in the blue is the habitable zone. Essentially the habitable zone is the region around the star where the amount of energy that the planet receives could allow it to sustain liquid water on the surface, given that the planet has sufficient atmosphere pressure. So that's a very vague description. But it is really it's not saying for sure that, you know, if a planet is in the habitable zone that it is for sure habitable. It is pretty much just a selection tool to help us locate planets of interest. And so the Venus zone is similar. The outer boundary saw the blue boundary that is shared with the habitable zone, that is the runaway greenhouse boundary. And at that boundary basically the amount of flux that a planet would receive at the boundary would be enough to prevent it from having liquid surface water on its surface. And so, because just because the energy would receive would make it too hot to sustain liquid water. And the inner boundaries of the boundary on the left the dotted line, that is essentially how hot a Venus like planet could get before it starts losing all of its atmosphere. So with that in mind with those boundaries in mind, planets in the Venus zone should not have any liquid surface water, but should still have sufficient or a prominent atmosphere. And so with this, we basically can determine whether a planet could potentially be an exo Venus. The other thing that is important of course is that the planet is rocky. And so the the limits kind of it's kind of fuzzy but the limits for how big a planet can get before it turns gaseous is around two times the radius of Earth. So we are interested in planets that are in the Venus zone and less than two times the size of Earth. And so, this is a sorry again for another plot, but this is basically the same plot, we have the flux which is just the amount of energy that a planet receives on the x axis here. And on the y axis again is the temperature of the star. The dotted lines are for the inner and the outer Venus own boundaries. And this is showing discovered known planets. And they're just color coded based on their, their radius. And so if you just focus on the red, so those are all planets with radii less than 1.5 times the radius of Earth. There is a lot. There is a lot of planets that are in this Venus zone. And so that is great. You know, we, it is nice that we have a large sample size so that we can, you know, have observations of their atmospheres open into to determine essentially your composition. But in general, there is a lot of planets that potentially be like Venus. And how do we determine, you know, the actual climates or surface conditions of these planets? Well, that's where the James Webb Space Telescope comes into play. You know, this telescope was recently launched. And thank God it launched safely and got to its location or its destination safely because you know it was a long time coming. But the JWC will be able to do a lot of things for a lot of different fields, but in particular for exoplanets, its primary use will be for conducting transmission and emission spectroscopy. And essentially with these techniques, we are determining the composition of the atmosphere of planets. And the, for anyone that's interested, the wavelength range is in the near infrared, which is around one to 25 microns. And so just a little visual on what transmission spectroscopy is. I include this little figure. So this requires a planet to transit, which again is when the planet passes in front of us and the star. And so when the light from the star goes through the atmosphere of the planet, it interacts with the molecules in the atmosphere. And molecules kind of have like a fingerprint where they will absorb light, but at different frequency or different wavelengths for each molecule. And so when that star light passes through the atmosphere and gets to us, we can basically look at all the different wavelengths of light that we are receiving. And if some of that light is missing, then we know that, you know, a molecule, a species in the atmosphere of the planet absorbed or scattered that molecule. And again, based on the wavelength that it was absorbed at, we can determine what kind of molecules are in the atmosphere. And you can also do this when the planet is behind the star, but it's just a little bit different because it is reflecting light instead of the light passing through the atmosphere. But this will be the primary method of us determining the composition of planets. But unfortunately, it will not be easy to actually learn things about exovenuses in particular. We have actually done this before this trans spectroscopy of planets, but primarily with giant planets in other systems. And that is because the planet is bigger, there is more light that is being absorbed because it has a much thicker atmosphere. And when I say giant, I'm talking about like Jupiter like planets just completely gaseous. And so there's a lot more absorption going on there. And so that kind of stuff was actually done with Hubble, but Hubble didn't have the sensitivity needed to do it with terrestrial rocky planets. And James Webb will have the capability, but with menaces that can actually get a little complicated. And so I apologize, this is an extremely busy plot. But this is an example of what's transmission a transmission spectra of a Venus like planet would look like. So the y axis is basically the the opaqueness of the atmosphere. And on the x axis is the wavelength that the atmosphere is opaque. And so as I mentioned before, you know, each molecule has a specific absorption fingerprint. And so CO2, which is the primary molecule in Venus's atmosphere absorbs at these wavelengths here, which is two microns to 174.3. And so with a Venus like planet, we would expect there to be a ton of absorption at these wavelengths because there would be a lot of CO2 and the CO2 would be absorbing the light. And so that's what we're seeing here. So these peaks are all absorption from CO2. But what I also did, and probably did 20 times because it looks more complicated, but I adjusted the height of the clouds in the atmosphere. And so Venus has clouds that go up to 120 kilometers and cover the entire planet. And so clouds are terrible for doing transmission spectra. They basically block all of the lights, whereas, you know, molecules only block certain wavelengths. And so they prevent us from learning a lot about planets. And so let's only just for now focus on this yellow line. So this is the transmission spectrum of the clouds at the highest point of this planet or in the atmosphere of this planet. This is based off of. And so when the clouds are this high, you are basically missing out on all the information that is in the other lines below it. So basically, it shrinks the size of the CO2 features and then any smaller features that the clouds are blocking we also don't get to see at all. And so in general, clouds will prevent us from learning things about exoplanets. And so another thing that's a problem is that Earth has a pretty similar transmission spectrum to Venus. So this is kind of the same thing we're just looking at, but now I threw in Earth's transmission spectrum in the red. And it's pretty puzzling because, you know, Venus has like 100 times as much or more than that. The atmosphere is extremely thick and has 96% CO2. Earth has, I think, like 0.004% CO2, and it's much thinner. So you would expect Venus to have a lot more CO2 absorption. But since the clouds are there, it negates a lot of that absorption, and it actually makes it seem like Earth has more CO2. And so this is another problem that we might encounter when looking at exoplanets that we might not be able to differentiate a Earth from a Venus. I'm going to try and speed through here, because I'm a little behind. And so the next question is, you know, can James Webb actually detect an exo-Venus? And so the simple answer is probably not. This plot here is showing the same spectra in black that we're just looking at, but in red is simulated James Webb data. And pretty much it just doesn't matter how many times we observe a Venus-like plant, just because the features are so small, that we would just never be able to differentiate it from a planet just not having an atmosphere at all. And so this sucks. But, you know, the thing is we don't really know what we will encounter when we are observing exoplanets. This is for an exact Venus analog, but in reality, you know, the atmospheres of planets in the Venus zone could be a lot different than what we see on Venus today. So it is yet to be seen how well we'll be able to determine the atmosphere composition of exoplanets. Okay, so after we get the spectra, the main thing will be determining the climates of the planets from just looking at their atmosphere. And so as we saw, you know, the clouds can prevent us from seeing the molecules in majority of the atmosphere. And so one of the challenges is determining the surface conditions on a planet just from observing the very top of this atmosphere. And that's where in situ missions come into play because we need to determine the climate of an exoplanet we model it using a climate model. And so the information that we put into those climate models will just be the information that we learned from their atmospheres. And so the more that we understand the connection between the surface conditions and what's going on the top of the atmosphere, the better we'd be able to model the climates of exoplanets from our observations. And one of the missions I'll be helping us improve these models is DaVinci was recently accepted, and it's awesome. Its main goals will be to determine whether there was water ever on Venus. And as well as just improving the general data that we have because the data that we currently have for Venus, again, is very old because it's all from those older emissions. And so the uncertainties are a lot higher and with the new data will be able to get a more firm understanding of the structure of this atmosphere. And I'm going to show a quick video just because this video will probably do a better job at explaining it than I will. So enjoy it's only a minute long. On the hottest planet in the solar system, a probe descends through a thick poisonous atmosphere. It is both a time capsule and time machine, unlocking secrets of the ancient past while revealing how a world can turn from possibly habitable to horrible. The location, Venus. Our sister planet has much to tell us about our own and exoplanets helping ignite a scientific renaissance for our universe. The mission brought to you by NASA Goddard and its partners is aptly named DaVinci Plus, the first US probe mission to Venus in over 40 years. With the probe acting as chemistry lab and photographer, other cameras will map and gather additional views of the planet from above, providing a new study of Venus that has scientific implications well beyond our own solar system. DaVinci Plus will give us a new understanding of planetary evolution. Launching in 2029, three years will be spent exploring our celestial neighbor, DaVinci Plus, coming soon to a planet near you. So yeah, I think the video is so cool. So yeah, that is a general idea of DaVinci. It will have, you know, a probe and an orbiter. Unfortunately, I don't have too much time since I spent a little bit too much time in the background stuff that is all good. But the main questions it will answer is, did the interplanets form the same materials? Did Venus have water ever? Did Venus have continents in the past, which is kind of a sign of plate tectonics and things like that? Let me see what else I can fit in here. So yeah, as I mentioned, it will have a probe that will just fall down onto the surface. It will most likely not survive the landing and then does not plan to. But on its way down, it will be taking in measurements of the atmosphere. And just to get an idea of what it will be doing. Missions in the past. Pretty much we're only able to measure the or investigate the top of the atmosphere and a little bit of the middle of the atmosphere you see there with the Vega balloons and pioneer. But DaVinci will be a complete measurement from about 70 kilometers down to the surface and the surface. The atmosphere near the surface we really do not know that much about. So DaVinci will be unveiling what is going on down there. And so, yeah, so help us understand, you know, there could have been two have a little planets in the solar system, which is a game changer, because we all have been, you know, living our lives with understanding that Earth is special and the only one. And I'm just going to wrap it up there. Sorry, I rushed a little bit at the end there. But in summary, Venus is more important than it is given credit for exoplanets will be a, you know, alternative path to understanding Venus and looking into the possibility of it being habitable in the past. And in situ measurements will be complimentary to that of the exoplanet studies, and will help improve our models that we use to model the climates on Venus like planets. And yeah, thank you. I appreciate all for having me and thank you all for listening. All right, thank you, Colby. That's really, really fascinating. And, you know, gosh, it sounds like an exciting mission. And I love the fact that at that, you know, looking beyond can help understand what's here. But, you know, then there's a synergy between the near and the far with this mission and it's great. And what acid question wouldn't Venus's atmosphere cause extensive erosion with all that acid and other things. Yeah, so that's a good question. So there is weathering. I think it's, you know, specifically chemical weathering when the atmosphere interacts with the surface. It is not to the same effect as, you know, erosion from water. Like the, you know, the chemical weathering won't be making a Grand Canyon on Venus. You know, water has a much more potent erosion effects than that. And so that is why we we the chemical weathering wouldn't be responsible for the lack of prayers that we saw. That's why they use that catastrophic resurfacing to explain it. But good question. Okay, and you might go ahead and stop screen share since you just have the last slide. They're great. So Mary asked, will the DaVinci probe and I think you alluded to this and will the DaVinci probe be able to take any images once it lands on the surface if it survives the trip to the surface. So what are the imaging capabilities of the probe all the way down. Yeah, so again, great question. So it will be taking images, but not from the surface. What it will be doing instead is taking images of the surface below as it is descending towards the surface. And the reason that they wanted to do that is because they wanted to see if there are any ties between the surface features or the geology below the atmosphere that they're taking the measurements in. So it will be taking hundreds of images as it falls. But I think once it hits the surface, they aren't planning on doing anything there. Okay, Bill asked or will either inside to or exoplanet investigations look at the effects of magnetospheres, especially on the existence or absence of atmosphere so I guess what's the relationship between atmospheres and magnetic surfaces. So hopefully I got that right Bill so you can correct us if we didn't so. So that is actually a pretty deep rabbit hole, especially as of recently. You know, it is predominantly thought of that magnetic fields are essential for a planet, you know, maintaining an atmosphere, and it does, you know, protect us from the charge stellar winds, which when interacting with our atmosphere can send molecules in our atmosphere flying to space, and over time, you know, we would lose our atmosphere. But Venus does not have an atmosphere does not have a magnetic field. And so the thought of a magnetic field being necessary, kind of doesn't work when it comes to Venus, because Venus has the thickest atmosphere out of all this racial planets. So it is actually unknown, whether magnetic fields help or hurt planets, because at the poles, it actually the magnetic fields actually like funnel stellar wind at the poles and that's why we see your aurora. And so that's in the solar system with exoplanets. Also I know it will be extremely difficult. And at least in the near future it'll probably won't be able to determine the presence of magnetic field on an exoplanet. There are ways hypothesized with viewing aurora on giant planets. But with our current sensitivity is it would be very, very hard. So it makes me think a little bit because I know that that that's was one of the areas of investigation on Mars and that was one of the things that Maven went was to investigate the, the, you know, lack of atmosphere on Mars and a lot of it had to do with the magnetic field but also there were there were some other implications which I don't know whether that would have anything to do with, with Venus, you know, I think it was the solar wind stripping the, the atmosphere away in any, you know, synergy with any findings there does that inform anything. Maven Maven is a great mission. It's hard to directly connect the two just because one of the primary factors of a planet sustaining an atmosphere is its mass. And, you know, more the mass the stronger the gravity, and therefore the stronger its ability, or the stronger it can hold on to the molecules in this atmosphere. So Mars is not very massive at all. And so it loses its atmosphere pretty easily. Whereas Venus is near the mass of earth and so it has an easier time. But another thing is basically when it when molecules escape a planet's atmosphere in the space. The reason they are doing so is because they are energized to where they're fast enough to exceed the escape velocity, which is basically how fast you need to go to leave a planet's gravity, a gravitational pull. And it is easier to accelerate lighter molecules. And so one thing that is a factor for why Venus has been able to keep its atmosphere is it's primarily composed of CO2 which is a heavy molecule in comparison to, you know, hydrogen or nitrogen. And so, since it is composed of mainly heavy molecules it is much harder to speed those up so that I can leave. So hopefully they answer your question. Okay, so, you know, Cliff has a good question. And on the descent of the probe he's wondering about, you know, a parachute or something to slow its descent down or is it just kind of a direct and then hit set, you know, terminal velocity. Yeah, good question. So no parachutes. I believe there's no parachute, but saying that there isn't. They use a technique called arrow breaking, which is where they basically use the friction of the atmosphere to help decelerate the spacecraft. And so this is used in a bunch of missions whether it's an orbiter sometimes they have like the satellite that's orbiting a planet dip into its atmosphere for a minute just to slow it down, just because of the friction that it has. And with Venus is probably actually a lot easier to arrow break just because the atmosphere is so thick. So the terminal velocity on earth is, you know, basically where the the as fast as you can go in and the terminal velocity on Venus would be a lot slower, mainly because it has a thicker atmosphere and less gravity. So no they won't be slowing it down, but it won't be going too fast or they won't be able to take measurements, essentially. So something you just said that was interesting this kind of leads into a question that Stewart asked and it's about, you know, the interior of Venus, which, you know, Da Vinci isn't going to be able to say anything but maybe you might say he says how solid is the surface to the core is consistent in the sense we understand Earth's tectonics, but then I want to come back to something you just said you said that the even that the gravity on Venus is a little bit less. However, it's approximately the same size as earth and so that would seem to indicate that we do know something about the interior of Venus. Yeah. So we do know it's average density, for sure, just using its mass and its radius. But something so the earth produces a magnetic field because it has a liquid outer core and the convection in that liquid outer outer core which is basically just the the the soup of metals in the core moving. So that movement creates a magnetic fields, but over time that liquid outer force solidifies and so when it is no longer a liquid and it can't convict that's when the magnetic field stops being produced and so there's things like that that's just using the average density to learn. And specifically to magnetic fields. There are ways to like check metals or rocks on the surface for like, kind of like a signature of past magnetic fields. Basically like the metals in a rock might be like polarized and the only way they may be polarized is from the presence of a past magnetic field so there are things like that that we can use to determine things like a magnetic field but on. Yeah, we just don't really know too much just from average density. Yeah, we could get down there with some handheld magnetometers or something and determine the polarity just like they use that for the spreading regions in the ocean floor back in the 60s. Okay, we're going to go for one last question here we are a little bit past time and so Jim K kind of brings up one of the more popular things from a couple of years ago is that there was the discovery of something in the atmosphere and and some, you know, implications for the potential of life as a source and so anything about that that you could, you know, comment on. Yeah. Just to be clear, you know, it is not currently a, it is a heavy super heavily debated topic. When that paper first came out about the detection of boss mean. I got a lot of publicity. And it's awesome that means was getting publicity because of it but since then, there's been like, I think like four or five rebuttal papers in response to their their work to try and show why it's not the case. And obviously this is why science works is because you know there is people that like to make sure that people's analysis is correct. But it's, it's something that we really won't know until we go there and this detection was. This detection occurred a good while after the missions were already conceptualized and all the different instruments were created. So I'm not positive as to whether they added instrumentation last minute to these missions to look for a solution. But I guess like personally, I wouldn't. I'm not too confident in it. It is definitely, you know, a little far fetched. I'm not saying it is impossible. I think the best thing about that the whole philosophy is just the added excitement about Venus and the potential that there could be life in the atmosphere and there is life in the atmosphere on earth. So it is definitely not a impossibility, but I just wouldn't bang on it too much. All the more reason to go there and more than once to so that you know let's make it a mission for us. Exactly. Yeah. Well that's all for tonight thank you so much for Colby for joining us this evening this is wonderful and thank you everyone for tuning in. So you can join us for our next webinar on Thursday may 19th, when we welcome back Dr Kelly lepo from the space telescope science Institute, who will share with us what we might expect from the release of the first images and the science return from the web telescope. So you can find an archive of these webinars and the next guy network website and the outreach resources section, each webinars page also features some additional resources and activities and I'll link to Colby's paper. You can also find these webinars on the next guy network YouTube channel. And so keep looking up and we will see you next month and we'll kind of hang here for just a few more minutes though.