 Hello, everyone, and welcome to the March NASA Night Sky Network member webinar. We're hosting tonight's webinar from the offices of the Astronomical Society of the Pacific in San Francisco, California. We're very excited to present this evening's webinar with Frank Summers from the Space Telescope Science Institute. Also welcome to everyone joining us on the YouTube live stream. We're very happy to have you with us. These webinars are monthly events for members of the Night Sky Network, though we look forward to live streaming these in the future. For more information about the NASA Night Sky Network and the Astronomical Society of the Pacific, check the links in the chat. Before we introduce Frank, here's Dave Prosper with a couple of announcements. Hi everyone. I just wanted to let everyone know that we understand that astronomy outreach is a little bit difficult right now to say the least, as we all deal with COVID-19. Just want to let everyone know that no clubs will be penalized for canceling events during this crisis, like not at all. We do ask that if you cancel an event to not delete it from your listing on the Night Sky Network calendar, but just change its status to canceled. And if you want to remove it from public view, you can also change an event's visibility from public to private as well as you're editing the event. This just helps us in NASA understand how many events were canceled during this time. It also helps keep members of the public from kind of popping into a canceled event and wondering where everyone is. So, congratulations will actually be counted as participation in the program at this time. So, it's all good. And I just want to add, if you've added events and had to cancel them, they'll still count for handouts and our prize contest that we announced a few weeks ago. In fact, we just had our drawing. So we got some great news there. The winner for our event drawing for this year, for this quarter at least, is the Northern Colorado Astronomical Society. I did that right before the webinar started, so I'll get in touch with you all shortly. They will receive a free Sky Quality Meter. Everyone else that posted 10 or more events, you all get in handouts. So, and of course, if anyone else would like any extra help or training with the Night Sky Network program or website, you can please, you can contact Andy Sherwood. She's our awesome trainer and champion and she can help you get up to speed on the NSN site and can be reached at a Sherwood at astrosociety.org. And you can also reach us all at our programs main inbox at night sky info at astrosociety.org or on social media at at night sky network that's on Instagram, Facebook and Twitter and YouTube. So anyway, I'm really here to dive into Hubble's history. This is going to be awesome. So back to your Brian and let's get on with the show. All right, thanks Dave. So for those of you who are on zoom. One of the things you can find is you've got a chat window and a Q&A window at the bottom of your zoom window on your desktop please feel free to greet each other in the chat window, or to the list know if you're having any technical difficulties. You can also send us an email at night sky info at astrosociety.org. Please make sure there's a little blue button down at the bottom. If you select it defaults to just the panelists. But if you want to greet some of your colleagues out there around the country, make sure that you click on that little blue button. And it might say everyone, or it might still say depending if you have an updated it might say all panelists and attendees please select that one. If you have a question for a guest speaker to answer please type it into the Q&A window. If there's a lot of chat going on which is absolutely fantastic but if you put a question in the chat, it's going to get lost tonight and so please put your questions in the Q&A window. It will help us keep track and also let us know whether or not we've answered your questions or not. We'll have a couple of times during the presentation when we'll pause and see if there are any questions that come up. So for people that want to know, we are going to record this and the video will be up on the YouTube channel, probably by the end of the day on Thursday. So I'm going to start recording now. Well, welcome to the March webinar of the NASA night sky network. This month we welcome Frank Summers to our webinar who will share with us some of the history and legacy of the Hubble space telescope. Frank Summers is an outreach astrophysicist who illuminates and elucidates the awesome beauty and intricate wonders of the universe for almost two decades. He has contributed to all aspects of the Hubble Space Telescope press education and outreach through news media websites, educational programs, social media and museums. His specialty is creating accurate and aesthetic scientific visualizations that have appeared in planetariums, documentaries and IMAX films. Please welcome Frank Summers. Thank you very much Brian. Very great to be here tonight. Okay, so I'm going to talk to you about 30 years of discovery. It has been actually next month it will be the 30th anniversary of the launch of the Hubble Space Telescope. And well, I've been around for almost 20 years of this. And it's just amazing to me just how far we've come with this one telescope. So here's my, oops, there we go. Here's my slide of myself. I call myself an astrophysicist, because I'm an astrophysicist who specializes in visualizations. Okay, I'm not going to be able to show you those visualizations on a webinar, but I do have a slide at the end that points you to our YouTube channel, where you can see some of the those those visualizations. So, where did Hubble come from. Okay, well, Hubble took a long time to become a reality. In fact, the first idea, the major idea, initiating instant of the idea came from Lyman Spitzer back in 1946. He was working for the Rand Corporation at the time, and he wrote a white paper on the viability and the utility of a space telescope. He recognized that that was over a decade before in the next image. Sputnik was launched in 1957 for both. It was over a decade before we were first entering into space that the idea was out there. And in, as I said, 1957 Sputnik was launched, which caused the next year in 1958 NASA to be established here in the United States. They now had a space agency. And in 1962, the National Academy of Sciences, in recommending ideas for what we should use the space agency for, they recommended that a large space telescope would be a should be a US national Well, astronomers, of course, were all over this and several different proposals for telescopes in space came about, and different groups came until they sort of coagulated into one group, but it really didn't get political muscle until 1976. And then 1976 was when NASA and ESA, the European Space Agency, combine their proposals, their ideas for putting a large telescope in space. That gave it the political muscle necessary in order to be funded. And in 1997, you, the Congress funded the large space telescope project. Things move relatively quickly after that. The telescope was was designed, built, put together, and in 1985 Hubble was complete and ready to be launched. Unfortunately, in 1986, we had the Challenger disaster, where the space shuttle exploded on launch, and the space shuttle program was put on hiatus for a while. However, in 1990, the space shuttle program was back and operating, and Hubble was finally launched and deployed. So what you should take away from this slide is that a space telescope, a large, great observatory space telescope isn't something that happens overnight. It takes several decades, and in this case, almost 54, 40, what is that, 44 years from Lyman-Spitzer's paper to when Hubble was launched in 1990. And so the new telescopes that you see that are going to be going up, they also have similar decades long stories behind them. So here is the Hubble Space Telescope is a beautiful picture of it in orbit. And along the left hand side, you can see a variety of facts about it. I'm not going to go through all of all these facts, but I really want to just get to a couple of them. And one of them is the orbit height. It's about 340 miles above Earth. Okay, now Earth's atmosphere extends for about 60 miles. And if you look in the back of this image, you can see that blue haze. And that's the haze of Earth's atmosphere. That is what telescopes on the ground have to look through when they're looking at the universe. They look through this haze and that haze actually distorts their views of the universe. There is a limiting resolution that they can have because they're on the ground. So the Hubble Space Telescope has what every real estate agent wants. It's got location, it's got location, and it's got location. Being above Earth's atmosphere, it doesn't have to look through the haze and it gets the clearest view while observing our universe. The other thing I'd point out is the orbit period and that it takes Hubble approximately 95 minutes to complete one orbit around Earth. I'm going to be speaking here for about 45 minutes or so. And so Hubble is going to make half an orbit around the Earth in the time that I'm giving this talk. It's moving at 17,000 miles an hour and still staying locked on a target so it can achieve that incredibly high resolution. And that's just an amazing feat of engineering. I'm an astronomer and I understand all the science and all the cool things, but I have an immense appreciation for all the amazing technology that goes into making this telescope work and work as well as it does. The other thing I really have to mention is the servicing missions. Hubble being in low Earth orbit being put up by the space shuttle has also been serviced by the astronauts. It was designed for this. On the right hand side, you see Hubble in the payload bay of a space shuttle. There's a special bracket in the back of the payload bay that Hubble is latched onto and then the astronomers do their space walks to service Hubble. There's an amazing group of astronomers that astronauts who have, sorry, astronauts who have serviced Hubble, and they've done it five times. They've replaced batteries, they've replaced gyroscopes, they've pulled out old instruments, put in new instruments. They've repaired things that were never meant to be repaired in space. They've done some absolutely amazing things. And I don't have time tonight to really tell you about all those things, so I'm going to leave those alone and there's plenty of other resources for finding out about those. Instead, what I'm going to be talking about are the images from Hubble. This is what the public loves and what really what I know best because it is the expression of the science that Hubble has done. Here, for example, are 30 beautiful images from Hubble, and we're going to go through a variety of these images. I'm going to tell you a bunch of stories about what it has seen. If I didn't exhaustive list of all my favorite things that Hubble has studied, we'd probably be here for about three hours. So I won't be able to get to all of them, and I apologize if I miss out on your favorite object. I'm trying to cover a large swath of things to give you a full feel for all the amazing things that Hubble has studied. So first, let's just start nearby. We ended up with a couple of questions here about the mission itself, and so this might be a good time to pop in here with these. Absolutely. So William asked, what's the current estimate for Hubble's remaining life? Well, that's an unknown question, actually. And it's really good that it's unknown, okay, because the Hubble, you know, its last servicing mission was in 2009. And so we're 11 years after the last servicing mission. And every year, every time we look at it, we say, oh, it'll last another five years. And then after those five years are up, you know, it'll last another five years. And here we are, 30 years in, and I still got to say it'll last another five years. One of the really cool things is that the folks have gotten so good at doing the technical support and the computer support, and really just working through it. And we've got 30 years of experience working with this telescope that they can fix an awful lot of things that they never would have expected they could fix before. So it's still doing quite well. And I will say I always have to give the standard answer another five years, and which is really good. So we'll be up there when James Web Space Telescope launches. And then Dennis asked, when they did the servicing mission, did they have to refuel any of the thrusters on it? Not that I know of in terms of refueling thrusters, maybe I'm not an expert on that. We do. We did, of course, in servicing mission for replace the batteries. The Hubble is powered by solar energy. It has the solar panels, of course. And so those batteries charge and then they expend and they charge and they expend and as you all know, batteries that are charged and then expanded slowly to grade over time. And so we replaced the batteries in 2009. And that really helps to give it a more secure and more stable power. But I don't know anything about the thrusters. Okay, and last question here for this step fast. How did Hubble get its name Hubble got its name from Edwin Hubble, the American astronomer. And Edwin Hubble is very famous for his work in cosmology. That's sort of the beginning of cosmology, uncovering that the Andromeda galaxy, what was at that time called the Andromeda nebula is actually the Andromeda galaxy. And then uncovering that the galaxies that we observe appear to be moving away from us, that the universe is actually expanding. So Hubble's understanding of the expanding universe, and even the discovery of that, that there are other galaxies besides our own, made him an important figure, and it was named after Edwin Hubble. All right. Okay, let's move on and talk about some solar system objects. First of all, this is Hubble's picture of Mars. Okay, and it's a fine picture of Mars. It's, you know, the nicest picture of Mars you can get from Earth, but NASA's actually sent a number of probes to emissions to Mars. And Mars Global Surveyor has much, much better images of Mars. What can Hubble provide that those emissions can? Well, this image here shows you that that it can provide time. Hubble has been up for 30 years. And every two years or so, Mars makes an opposition to Earth, and Hubble observes it and Hubble can watch over time to see the changes on Mars, and to catch special events in 2001 that image down at the bottom of it. And that is of the image we took of Mars in 2001 while it was at opposition. And then just a few months later, the dust storm that was brewing in the Hellas Basin on in the lower right of that image became a planet wide dust storm. We were able to catch and watch a planet wide dust storm form on Mars simply because we have such an incredible resolution and can sit and watch it over time. So for the solar system sometimes I refer to Hubble as being interplanetary weather channel for things. We also had the advantage of time on Jupiter. This image here shows prominently Jupiter's great red spot. This is a storm on Jupiter that has been raging for centuries. We have continuous observations back to the early 1800s. And it may have been actually around since 1670. There's a paper written by Giovanni Cassini in which he draws Jupiter and I swear it looks like the great red spot is there on Jupiter. We have continuous observations to say that it was there but this storm has been raging for 200 years. But while Hubble has been watching, it's actually been shrinking. On the right hand side, you can see the images of it from 1995 2009 and 2014. The images are scaled so that you can see that the great red spot has been shrinking. Not exactly sure why. We do know that the great red spot is a place where energy is coming out of Jupiter. We've also seen a little less energy and we've also seen the formation of red spot junior and such. So there are changes going on inside Jupiter and we can monitor them over years. Now when looking at Saturn, Hubble utilizes another one of its special capabilities and that its ability to look in ultraviolet light. But everyone thinks, oh no, we'll go outside and the ultraviolet light is going to give you a sunburn and everything. But really not much ultraviolet light makes it down through Earth's atmosphere. To do ultraviolet astronomy, you absolutely need a space telescope. And what you see here on Saturn, these are composite images of a visible light image of Saturn with ultraviolet light images of the aurora on Saturn. And these observations were actually kind of surprising because Saturn is 10 times further away from the sun than Earth is. So the solar wind which produces the aurora, it was going to be one 100th the density that it is here on Earth. So what was surprising about this was that the aurora was so strong on Saturn. And then if you know that these images were taken two days apart, and they look very, very different. The surprising thing was the variability that we see in Saturn's aurora. So by utilizing its ultraviolet capability, we're able to study these amazing aurora and the variety of the aurora on Saturn. Now the last thing in the solar system I want to talk about is the Pluto, Pluto, Karen and its system. And I've got three images here for you that cover the span of Hubble's observations of Pluto. The top left is an image from 1990 of Pluto and Karen, and you can see them clearly separated. Now, if you remember when Hubble was launched, there was a flaw in the mirror. It was ground to a very exact shape, but it was just slightly wrong, okay, the measuring instrument that told him what was the right shape was actually incorrect. And so even with the flaw in the mirror, Hubble had better view of being able to resolve Pluto and Karen than we could get from the ground. I just want to make sure everyone knows that during its first three years, Hubble was not useless. Hubble was actually doing science. It could see better, but not all the science that it was intended to do. So we can see the Pluto Karen system in 1990. And then the center image is a map of Pluto that was done in the early 2000s. I think this was 2002. And this is not an image. This is actually a computer generated map taken from many images of Pluto. And then using computer processing to interpolate to get higher resolution than Hubble could actually get. Hubble can't see Pluto at that kind of resolution, but when you use computer processing to combine many, many images, then you can tween out details and interpolate details that you otherwise couldn't see. And on the right in the lower right is a 2012 image of not just Pluto and Karen, but also the four moons that Hubble discovered around it. And if you remember, in 2005, the New Horizons mission was launched to go to the Pluto system. And Hubble was the only telescope available to be able to see the details in the Pluto system that could identify if there are any going to be any problems for the New Horizons mission. Nobody really expected to find much, but turns out we found in 2005, Nix and Hydra, and in 2012, the two smaller moons, Styx and Kerberos. So the Pluto system became tremendously more interesting because not just Pluto and Karen orbiting around each other, but also four moons, Nix, Hydra, Styx and Kerberos orbiting around it. And Hubble's resolution was able to find that. Okay, now we get to stars and nebula and let's see, are there any more questions in the Q&A? Yeah, we've got a couple of good questions here. I think that people are interested in some of the nuts and bolts about how we do this. So Chris and let's see. So Michael and Rosemary actually have kind of a similar question. They're wondering about how are targets chosen and how do you know what the next one is going to be? All right, so that's two actually two really good questions. One, the targets are chosen by a large group of astronomers that gets together and evaluates proposals. And the telescope assignment committee, the TAC, gets together and all the astronomers from around the world submit their proposals and they are evaluated. And generally over the course of Hubble, it's been seven to one or ten to one, the number of proposals received to the number of proposals that are approved. So if you have a good idea of what to observe on Hubble, you've got a one in seven, one in ten chance of actually getting it done. So only the best science that really needs Hubble gets done and that's where the chargers are chosen. And then when you choose what is the next one, well, we have a amazing group of people that do the telescope scheduling. And originally the schedule was put up like two months in advance, 60 days in advance, and then they shortened it to 45 days, and then they shortened it to 30 days. And they've got it down to less than two weeks in terms of being able to schedule efficiently Hubble's moving from target to target slowly across the sky because that's actually what you don't want to lose a lot of time in. You don't want to lose a lot of time slewing across the sky. So you want to get your targets in and so they're nearby in the sky and Hubble moves very slowly across across the sky to slew. So it's a very difficult problem of scheduling these things, but they've optimized it such that it's down to like 10 days or 11 days in terms of the scheduling and they do an amazing job. All right, Barbara's got a good question and then John has a similar one. Barbara asked is Hubble definitely going to be de-orbited when James Webb Space Telescope goes live, or are they both going to run concurrently if Hubble's still in good health? And John had the similar one about the re-entry de-orbiting into Earth's atmosphere. Okay, so first of all, as long as Hubble is doing cutting-edge science and science that no other telescope can do, can't be duplicated, I expect if Hubble is still in good health, Hubble will still operate. The James Webb Space Telescope is not a replacement for Hubble. It is a complement to Hubble. James Webb Space Telescope operates primarily in infrared light. Hubble operates primarily in visible light. The two are complementary. And we actually look forward to several really great years when the two are looking at the same targets and we gain much more information about those targets because we have both telescopes looking at it. The other question about the de-orbiting, I cannot speak for NASA on this because I don't work in this part of it, but the plan as far as I know has been that there is a soft capture mechanism that was placed on Hubble in servicing mission four. And when Hubble is no longer useful, we cannot allow it to just randomly enter Earth's atmosphere. If it de-orbits, it cannot randomly enter. It needs to be guided on a re-entry so that it will not hit any populated areas. It needs to be able to be taken down into the ocean safely. The plans for how that will occur are not known to me, but we do not have any, we don't have the space shuttle anymore. We can't get up and service it. We can't do things like that. So that is the current plan. But as I will say, others know more about that than I do. All right. Well, we've got lots of other questions, but I think we need to move on. Okay. Now we get to the fun stuff, the stars and nebulae. This is the stuff that most people know. I'm going to start with a relatively boring image. This is a star. Oh, kind of boring. It's just a spot of light. But you got to recognize this is a really cool image of a star because stars are so small and so far away that they are basically dots of points of light, unresolved points of light. This is a resolved point of light. This is not just any star. This is Betelgeuse, the shoulder of Orion, and it is a red super giant star. It is huge. It's 700 times, its radius is 700 times the radius of our sun. It is so big that this is the size of Jupiter's orbit in comparison. If Betelgeuse were in the center of our solar system, Mercury, Venus, Earth, Mars, the asteroid belt, and Jupiter would all be orbiting inside of Betelgeuse. That's how huge this star is and it's close enough that Hubble was able to resolve it into more than just a point of light. And that was a tremendous achievement in the 1990s to be able to resolve a star into something more than just a point of light. So Hubble's resolution using the faint object camera was able to actually resolve at least a huge star. Now a normal star, hey, that's still a little bit too far away. That's a lot more to do. But at least a few of the largest stars can be resolved into more than just a point of light. But if you want to see a lot of stars, well, this is a piece of the globular cluster Omega Centauri. And it's a really colorful image going from the blues and into the yellows and then on to the reds. This actually was a calibration image for at the end of service mission four to test out wide field camera three. And what is special about this image is besides the fact that it's just a cool panoply of stars is that it is in ultraviolet, visible and infrared. Hubble, as I said, operates mainly in visible light, but it goes some into the ultraviolet and it goes some into the infrared. This image demonstrates the pan chromatic nature of wide field camera three. And besides being a gorgeous image, it really showcases that Hubble can do ultraviolet optical and infrared astronomy and compare the different wavelengths altogether. But if you really want to look at globular clusters Hubble really is your is your instrument. And for example, is the globular cluster Messier 80. And globular clusters are just amazing dynamic laboratories because they consist of 10,000 100,000 a million and in some cases even maybe 10 million stars, all orbiting around each other. I mean, this is an amazing test of gravity you're seeing just stars swinging around each other. And the problem is, is that when you look at their centers, they're very, very dense with stars. And you need Hubble's resolution to be able to look deep into the course of these globular clusters, follow some of the star motions or track the track of track a bit of the star motions over time, and see the details of the structure of these of these globular clusters. It's an amazing dynamic laboratory for looking at gravity and its effects and Hubble is you want to do it. Yeah, Hubble is is is your telescope for for looking at that. Now stars don't exist on their own they of course exist inside nebulae. And one of the most amazing nebula in the nearby universe is the Orion nebula. And this is Hubble's image from 1995. And I will say that Hubble has an even better image from 2000 and 2006. But I'm going to use this image because it shows off some of the amazing detail that Hubble was able to get. These are stars that have just been born. They are about two to five million years old. And right in the core, you have these four bright stars called the trapezium they're really big honking bright stars. And these stars are the stars that emit the high energy radiation that heats the gas and causes the gas to glow in Orion. They also emit strong stellar winds and if you look close at this image, you can find evidence of this. And the lower left one you see something that looks sort of like a wind sock. And that's exactly what's going on here. The wind from the biggest star theta Orionis one C is blowing across the nebula. It hits the gas around a star that's still forming material that's collapsing onto the star, and it blows it back into this wind sock. That's the stellar wind from theta one C blowing across another baby star. That star might be trying to form planets and such around it, but the intense radiation from theta one C might be interrupting it. How do we know that stuff is forming? Well, if you look at the other image in the lower right, you can see a newborn star, and then a dark disc of material around it. That is a baby star. And around that baby star is a disc of material. And inside that disc of material is where planets are forming. In 1995, we got a look into the Orion Nebula with unprecedented detail to be able to see star and planet formation going on. This is only two million years old. I know two million years sounds like a long time, but our sun is four and a half billion years old. So these are really baby stars and baby solar systems that we're able to see in the Orion Nebula. Another amazing star formation region is the Pillars of Creation, the Eagle Nebula, also called M16. And here we have three images of the Pillars of Creation. On the left is the original 1995 image that sort of was the watershed for Hubble in terms of getting the public's attention like, oh my God, this is just amazingly beautiful stuff. But it also was really cool because it has scientific, a lot of scientific detail in there as well. And in the center image is a revisiting of the Pillars that we did in 2015. And at the left hand pillar is about one light year in height, a full light year. The nearest star to the sun is about four light years away. So this is a really long pillar. And then the very top are where stars are forming. The radiation from a cluster of stars that's way off up the top of the screen is blowing down across and these dense regions where the stars are forming block that wind and create these Pillars behind them. And the Pillars may appear as if they are solid Pillars, but they're not. If you look in the right hand image, you can see the infrared view from 2015. And you can see that the Pillars in there, and some of the trunks of the Pillars fade away. The tops stay because they are actual dense regions, and that the Pillars really are the shadows of these dense regions due to the wind. And you'll see the incredible number of stars that you see behind the Pillars because the infrared radiation is longer wavelength and passes through a lot of gas and dust to see more and beyond. So this is a great example of being able to look in the optical and look in the infrared and get two views complimentary views of the same object and learn an awful lot more about what's really going on. The star forming region I'd like to talk about is the Karina Nebula, and this is an amazing 300 million pixel mosaic of Karina. Just awesome image here, it's just full. And the star cluster on the right hand side in the middle is called Trumpler 14 and there are actually several, you know, really bright clumps of stars that have evacuated this big cavity. Down below those star clusters, you can see some Pillars and such, but I'd actually like to highlight what's happening right up and to the right of that star cluster in something, a region that we called Mystic Mountain. These are Pillars, they're like the Pillars in the Eagle Nebula. But one of the things is, is that you see at the top of the pillar, you see a jet spewing out. The star forms. It often has material spewing on to coming from that disk onto the star, and the magnetic fields then spew that can spew that material out into oppositely directed jets. You see it not only at the top pillar, but also that pillar on the left, you can see these jets spewing out, indicating the star is forming in there. You can see all these jets, you know, the birth announcements of stars. And you get this amazing view of that in the Karina Nebula. Also in the Karina Nebula on the left hand side is the doomed star, Edakar and A. Edakar is an amazing star that was really bright in the 1840s and then faded away and didn't really know until Hubble was able to see. And you can see these huge bubbles that have been emitted by the star, these bubbles of gas spewing away from from the star. This star is thought to be 100 to 150 times more massive than our sun. It will definitely go supernova and explode sometime in the next few million years. We sometimes think of this as perhaps this is what's going on in a pre supernova star. It has these major outbursts and just incredible detail that we can see in this outburst of the star in the Karina Nebula. The Karina, the Edakar will will die by a supernova, but not all stars will die by supernova. Some of them die by what's called planetary nebula. And one of the most beautiful planetary nebula is this one that is actually called the bug nebula. In the Hubble press release we said resemble the butterfly and everybody stuck with that name. And so we accidentally renamed this nebula via press release from the bug nebula to the butterfly nebula. And so here is the butterfly nebula. And you can see that it's sort of like a hourglass shape that is cinched at the waist. Now there is a disk of material blocking the outflow at that cinch point. And instead everything blows off in two directions forming these hourglass lobes. This is actually the material of the star, the outer atmosphere star being blown away as the star dies. It runs out of the fuel for its nuclear fusion. It goes through an instability phase and blows off these outer layers. You're exposing the core of the star. This star I'm told is 200,000 degrees. It's so amazingly hot. It heats that gas, it glows, and Hubble was able to capture this amazing view of it. That's a planetary nebula. That is sort of stars going gentle into that good night. The stars that do not go gentle into that good night are those that do the supernova. And this one is the crab nebula, perhaps the most famous supernova remnant. And this one is just tremendous detail of the guts of a star blown out into space. And originally when I learned about the crab nebula, it was like, okay, this is a supernova explosion. This is the blowout from a star that has exploded. And you see all these interesting tendrils. But it's so much more than that, actually, because there is the crab pulsar at the center. And the pulsar at the core of the crab nebula is emitting tremendous amounts of energy. And that energy is what is heating a lot of almost all of this gas and causing it to glow. This is not a standard blast wave supernova remnant. This one is actually a pulsar wind nebula. And so one astronomer said to me that if the crab pulsar didn't exist, we might not see anything in the crab nebula. Because the energy that drives the radiation that we see here in visible light actually derives from the pulsar and not directly from the supernova explosion. But it's just a tremendous detail and structure of all these outflows and all the energy outflows interacting with it that create the crab nebula. And that ends our star's nebula section. And so let me ask a couple of questions here and I'm just going to kind of throw them all out there and let you kind of have at them. And so Stuart was wondering about the camera resolution for the wide field camera. So we have a technical one and then cook was wondering about the average exposure time, or how much how long it takes to actually gather enough light to produce the images. And then if you could maybe make a comment about the colors in the Hubble palette. We always get that question. Alright, so what was the first one resolution. Alright, Hubble's resolution is about 120th of an arc second. Alright, let's explain that I there are 360 degrees in a circle. There are 60 arc minutes in a degree. There are 60 arc seconds in an arc minute. And Hubble's resolution is 120th of an arc second. So that's a really, really small angular size on the sky. So that Hubble has incredible resolution, but it also limits its field of view that it only is looking at a few arc minutes across, even in its 4k by 4k images, the detectors on with C3 are 4000 by 4000 pixels. What was the second question how long the exposures are okay so when you are awarded time on Hubble. Orbit in terms of orbits, you get, you know, one orbit or five orbits or 10 orbits. The largest proposal that ever happened was this really long proposal over three years that got like 900 orbits, okay. So getting 12 orbits you're doing incredibly well. Alright, and each orbit is, as I said about 95 minutes. Depending upon where your object is in the sky you may only get half of that orbit usable earth might block part of your part of your orbit so you can actually schedule Hubble to take several exposures during an orbit. So, you know, for bright objects like Jupiter, you don't need that long of a thing for if you're looking at a distant galaxy, you need quite a long exposure and you'll take many orbits and you'll add co add them together. The deep field that I'll talk about in a minute was about a million seconds worth of co added time put together. The second question was about the, the colors, and the colors in Hubble images are derived from the filters that we use. Now, Hubble is not a your, your, your cell phone camera in space Hubble doesn't take the standard right red green and blue filters that human sees. It takes filters that it does have those broadband red green and blue filters for certain for when the science demands it, but often the science demands very narrow band filters that just get the emission from hydrogen or just gets the emission from nitrogen or oxygen or silicon things that are diagnostic and tell us about the physics that are going on in each object. And when we have a image that's composed of all these narrow band and broadband filters, we assign colors to each filter. Is it what the human eye would see. No, it's not what it's a scientific instrument it's supposed to go well beyond what the human eye can see. And so the colors are the the photons are real, they're all from the data, but the colors that are assigned are there to illustrate what is going on in the different filters that we use to observe the different objects. All right. Okay, moving on galaxies and the universe are a third section here. All right. So I was only allowed to choose one galaxy image for this and it sort of tore me up. But I have to say if I have to choose a galaxy, I'm going to choose the whirlpool galaxy. This is a almost 100 million pixel image of the detail of what's going on in the whirlpool galaxy and what I love so much about it is beyond the fact that it's an absolutely gorgeous spiral structure. And what you can see is you can see those dark dust lanes. These is the dark dense gas where stars are going to form from this is the dark dense gas, and then you've got those red dots along it those other star forming regions, each one of those red dots. That's another Orion nebula or larger. Okay, thousands upon thousands of stars are forming in each one of those red dots. And after those, those star forming regions blow away their gas they high energy radiation and the winds and even some supernovae from those those high those massive stars blow away the gas they leave behind those bright blue star clusters the hottest brightest stars that only live for 10s of millions of years or so. They, they appear as the bright blue star cluster so if you look along the spiral arms in the whirlpool galaxy. You can see those dust clouds, you can see the star for regions in red, and then you can see the resulting star clusters in blue and it's an amazing illustration of the formation of the progress over time of forming stars here in the whirlpool galaxy. Another of my favorite things to look at a galaxies is galaxy collisions. Now, stars are so far apart and so small that they almost never collide. Okay, sometimes they colliding in globular clusters, but galaxies are not that far apart compared to their diameters, and they can collide. But still not, still not often but they can collide. And in 2008 we released a press release that had 59 images of galaxies interacting. And you can see an amazing panoply of all these galaxy interactions here from things that are look like they're just about to approach to things that are starting to just pass through each other, and things that are ripping each other apart and distorting their, their shapes. And it's amazing to think about what we've learned about the role galaxy collisions play in the building of galaxies since I was a graduate student, you know, around the time Hubble was launched. And the galaxies, these mergers and these interactions actually build up larger and larger galaxies. And it is now currently accepted the idea that elliptical galaxies, the giant elliptical galaxies that we see at the cores of clusters are actually formed through these galaxy collisions and mergers, and that they are the result of many mergers of many smaller galaxies together. The thing we find out in galaxy collisions is illustrated here in the antennae. On the left you see a ground based image with a sort of an overlay of the Hubble image on it. And you can see why it has the name the antennae, because of that, the long thin spokes pointing up and pointing down to get the name the antennae. When Hubble looks at that core that center on the right, you see an amazing amount of star formation going on. Again, as in the Whirlpool galaxy, those red regions are the places where stars are forming. And in the antennae we discovered something that we hadn't seen before, something that called super star clusters. A cluster of stars of 100 stars and such, that's a normal star cluster. And then you've got these globular clusters with hundreds of thousands of them. And then you have these in between things that are formed in these mergers, where you excite an incredible amount of star formation, and you get these super star clusters forming there incredibly dense, incredibly bright, and have many more stars than your normal star formation regions would get. So not only do galaxy collisions build up larger and larger galaxies, they also slam those gas clouds together and induce rampant amount of star formation. galaxies also are found in these vast clusters. And this is one particular vast cluster, one of the actually largest clusters in the universe called a bell 370. And you can see at the very center, one of those giant elliptical galaxies that I was talking about having been built up in these clusters, you get the mergers and you build up the giant elliptical galaxy. But this image illustrates one of the things from Einstein's general relativity. And if you haven't taken your general relativity course, I'm going to teach it to you in three words. Mass warps space. Okay, that's all you really need to know about general relativity. The presence of mass warps the space around it. And in these giant clusters of galaxies, the space is so warped that it actually bends light. They're gravitationally lensing clusters, the light of galaxies behind them that passes through stretches warps and deforms. And let me show you a huge example called let's nickname the dragon. This is on the left edge of this sort of dragon shaped objects or the dragons head on on the left is a galaxy. And the dragon's body is actually several other views of that exactly same galaxy. The light this galaxies on the far side of this cluster, and the light passes through this cluster and warps and stretch and changes direction, so that we see the galaxy along several lines of site through this cluster. The gravitational lensing is so great that I believe there's one, two, three, four images of this galaxy that make up the dragon. It's really hard to tell because it's so stretched out along most of the dragon's body. So you are seeing what I like to call visual proof of general relativity. Newton's gravity can't make this image. Einstein's gravity general relativity is required to get this gravitational lensing and Hubble has actually been the premier telescope because of its high resolution for seeing all these gravitationally lensed arcs in these of these massive clusters. Furthermore, these massive clusters because they act like a lens can allow us to see even more distant galaxies than Hubble otherwise could. So what we have done we've done several projects where we're looking through these massive clusters using them as a lens to magnify the light of a very distant galaxy and see galaxies 1112 and almost 13 billion light years in to into space. So we can utilize the lens of this gravitational lens to see to help Hubble see just a little bit further into the universe. And when we're talking about seeing deep into the universe. We have to of course talk about the Hubble ultra deep field. Hubble has since 1995 has a legacy of looking at very deep looking at one spot in the universe for a really, really long time. In 1995, it was actually a huge, huge risk, because we had no idea what we would see no other telescope could make this observation. And the director was going to put an entire week of Hubble time to one observation looking at one spot in the sky. And he saw 3000 galaxies. And then we did the Hubble ultra deep field in 2003. And we saw about 10,000 galaxies in a tiny region of sky. And what's amazing in years for light to travel a billion light years across the universe. So when we look at these galaxies, some of them like this this yellow galaxy in the lower right that's about five billion light years away. So we're seeing it as it was five billion years ago. The light has taken five billion years to traverse space before we see it. And some of them are eight, nine, 10, 12 billion light years away. We're seeing a core sample through the universe. What's even more important is that, you know, galaxies don't change much on a million years, or even 100 million years, you know, our, our sun takes 200 million years to orbit around our galaxy, 200 million years, not much for a galaxy. But a billion years, then you're talking about some time. We see galaxies that are 10 billion years light years away, seeing them as they were 10 billion years ago. We're starting to see, you know, if today's galaxies are adult galaxies, we can start to see the teenage galaxies. We can start to see the elementary school galaxies. We start to see the toddler galaxies. We're seeing galaxies as they're developing over time. And that's shown in this image where the lower one are galaxies out to about three billion light years, and they look pretty much like normal galaxies, like galaxies we see in our local universe. Then you go three to seven billion light years away three to seven billion years ago, and you can see the structures there but not really develop not really fully developed. And if you go seven to 10 billion light years away, seven to 10 billion years ago, you can see that the structure is is just beginning. You've got the core, you've got a bit of a disk forming around to create these spirals, but you can see the development of spiral galaxies over time by looking through all of these deep fields and examining the galaxies and the galaxy development over time. So that is a exploration through these amazing suite of images from planets to stars to nebulae to galaxies and out to the edge of the universe. And do we want to stop for questions here. Yeah, I think so and we're right at the top of the hour and so we want to make sure that we're, you know, I have one more point to make after this. Yeah. So yeah, let's we've got a couple of good questions here. Let's see we ended up with a lot of questions and we apologize right off the bat that we're not going to get to all of the questions that were posed. So, so David asked, did, did Hubble image the recent changes to beetle juice? Hubble has not as far as I know, I'm looked at battle juice. It can be done from the ground. So there is as far as I know, no major impetus to be doing it with Hubble. If it can be done from the ground. It's not going to happen. Okay, and then we had a good question. Andy asked, do the publicly released images correspond to the most useful ones to scientists, or are they just the prettiest ones are there other scientifically useful versions of the same image that the public doesn't necessarily see. So the ones that get released to the public are have two major reasons for the being released. One is there's a good scientific story. Our press releases are there to tell the science stories the discoveries made by Hubble. And if it's a pretty image, it can also get a press release just for being a pretty image. But generally it's got to have a science story behind it. And I got to say some of the press release images aren't all these gorgeous pretty ones I've shown you here. Some of them are not terribly not terribly beautiful, but they're scientifically important and that's really what we want to get across is that Hubble is a science instrument and it's being used for science, and that's the main value of Hubble is in the science. There are tremendous number of more images in the archive, the Mikulski archive for space telescopes massed, and there are some amazing image processors that raid the mass, pull up things and turn them into gorgeous images. We release a number of the other of the gorgeous images, but we can't release them all. Okay, then going back to the images, a couple of questions suje asked, so was the crab nebula picture taking completely in the visible. The crab nebula image was done in visible light. It was done in narrow band filters. And you can. Yeah, on on Hubble site, you can find the filters that it was actually that it was done in. And Dennis asked again about the images some of them are composite images of multiple images or the mosaic so how many images did it take to make the mosaic picture of the pillars. The pillars. Let's see the pillars was about 67 million pixels. So I'm going to say that was probably a two by two pointing. So four pointings of Hubble that were then mosaic together to create that full image that 2015 pillars image. All right.