The James Webb Space Telescope: Staring at the edge of space itself | TORSTEN BÖKER | TEDxLimassol

foreign [Music] [Applause] it was last Christmas that my fellow astronomers and I and in fact everyone around the world who has an interest in learning about the universe we all got the most amazing and wonderful Christmas present you can imagine let me take you back and show you what happened on Christmas morning last year immunity thumbs up from Jean-Luc Voyer all systems are go we're inside a minute now T-minus 30 seconds and counting standing by for terminal count uh final this nurse with set sis thank God Unity top and we have engine star s liftoff from a tropical rainforest to the Edge of Time itself James Webb begins a voyage back to the birth of the universe punching a hole through the clouds 20 seconds into the flight good pitch program reported [Music] [Applause] what you just saw was an Ariane 5 rocket launched from the European Spaceport in Kuru French Guyana which is on the North coast of South America it carried with it the James Webb Space Telescope and Observatory designed to unravel the mysteries of the early Universe with capabilities so Advanced and so powerful that it truly represents a Quantum Leap for astronomy I was among those happy people that you saw there at the end of the video cheering the rocket on as it descended ascended through the clouds we had every reason to be happy because the launch was Flawless all the way through the powered Flight of the rocket and including the picture-perfect separation from the upper stage that you see in this beautiful farewell pictures the last images we saw of web before it disappeared we were giddy with joy excitement and chia adrenaline especially when we saw the solar array unfold which you can see here which was a very important first milestone for the mission so what exactly is the James Webb Space Telescope it is without the doubt the biggest boldest and most challenging telescope Humanity has ever built it took almost 30 years and the teamwork of three separate space agencies to put it together NASA the European space agency and the Canadian space agency at a cost of almost 10 billion dollars you may ask why why spend so much time effort and money on an undertaking that is so challenging and so difficult and so risky my very personal answer to this is we do it because we're human and humans are very curious species by Nature we cannot stop asking difficult questions and neither should we because it defines us as what we are and it's the only way for us to evolve and make progress and Webb promises to answer some of the most fundamental questions we have what when and how did the universe and everything in it form what exactly is everything how do galaxies grow the massive black holes that occupy their centers and other planets like Earth around other stars and can we maybe just maybe find signs of biological activity in their atmospheres all these questions and more could not be answered with the instruments we had before web not with a Hubble Space Telescope and not with even the biggest telescopes on Earth so let me tell you why web is such a game changer the one thing we know about the universe is that it is expanding and because of that expansion light that travels through space over vast distances and billions of years it gets stretched along the way so that it arrives here today with the wavelength longer than what it started with you may have heard the term redshift that's exactly what this is the transformation of light to longer and redder wavelengths the further an object is from us the more its light gets redshifted and in turn if we can measure the red shift we know how far a galaxy is from us and from this we have learned that the most distant galaxies in the universe are 13 billion light years away that means that their light has traveled to us for 13 billion years before it reached us just think about this for a minute the earliest ancestors of modern man evolved maybe 300 000 years ago we didn't really know how to write things down we invented scripture only maybe 5 000 years ago and we only learned to use electricity 300 years ago but with web we can now capture light that is 13 billion years old and we can use it to learn about the universe and how it looked like at a time when the Earth and the Sun didn't even exist yet web is such a powerful tool because it can detect the faint redshifted Starlight from distant galaxies that has traveled over such long distances to us it can do so because web is extremely good at detecting these signals these infrared signals and when I say infrared you should know that this is just a fancy term that scientists use to describe heat web is extremely good at detecting heat it's a heat detection machine and just to give you an idea of how good I mean if you were as good as web as a detecting heat you could spot a single bumblebee on the surface of the Moon just by sensing its body heat I find that pretty amazing and the reason that web is so good is that we had built it in a way that's completely different from any other telescope before it in almost every way web breaks the limits of what has been tried before let's start with a large segmented mirror with its 18 hexagons it is six and a half meters across which doesn't sound too impressive until you stand right next to it it doesn't just look golden it's actually covered with a with pure gold which is extremely important because goat is very very good at reflecting heat without getting warm itself that helps the sensitivity of the telescope but in case you're wondering that's not the reason why web costs 10 billion dollars in fact the layer of gold is so thin that only two or three wedding bands worth of gold are enough to cover the entire surface what's more important for web is that we need the telescope and the instruments to be super cold in order to detect those faint traces of heat which means that we have to protect them from the warming glow of the Sun and the Earth at all times and that's the reason we had to build a huge sun shield to protect the mirror but you can see it is roughly the size of a tennis court and it's made from five layers of super thin coated foil that work together to reflect all heat back to where it came from so that in its shadow the telescope can reach these very cold temperatures it's about minus 230 degrees that we need to reach it's not your average freezer temperature in order for the sunshield to do that we need to send web very far away from Earth in fact we have to send it about one and a half million kilometers away to the so-called second Lagos point or L2 for short as you can see here it's about four times the distance to the Moon far beyond Earth orbiting telescopes such as the Hubble for example the advantage of L2 is that here web can rotate can Circle the sun together with the Earth so that at all times Earth Sun and Moon on the same side of the sun shield as you can see in this little animation that's really the secret why we reach those super cold temperatures and why web is so amazingly sensitive the downside of course is that L2 is too far away for astronauts to reach it and make any repairs if should something break on on the web okay so we need a huge golden mirror to capture faint traces of heat and even bigger sun shield to keep it all cold and we have to send it far away from Earth okay sounds sounds like a plan right so let's launch it the issue with this is that there is no rocket large enough to carry a telescope as big as web so we had to find ingenious ways to fold web up like a piece of origami paper to make it fit into the rocket this and then of course after launch and in space we had to find ways to safely unfold it and or rather have it unfold itself safely and reliably that's an incredibly challenging engineering task and it took us a long time to figure it out the way we gain confidence we can do this is by testing and re-testing and testing again because this was this is a really risky undertaking and in many of these tests we had to replicate the conditions in Space the vacuum and the supercode operating temperatures of web so here's an example of one of those tests it shows the web telescope being put into the biggest vacuum chamber we have on Earth it's at the Johnson space flight Center in Houston and you can perhaps spot the people in this picture to give you a sense of the scale in those tests we did indeed find a few issues and problems that needed fixing and solving and then retesting it again until we finally were sure that we can pull this off so in the summer of 2021 we finally had convinced ourselves that we were ready to ship Webb from Isla last test facility in California to the launch site in Peru this trip involved a giant customized container very slow travel over the Los Angeles highways to a boat which then took web on a 16-day trip from the Pacific to the Atlantic and through the Panama Canal until it finally arrived safe and sound in Peru it was only then that after so many years of preparation I dared to believe that this might really be happening so when launch day arrived it was a big deal indeed we had lots and lots of media attention and very many very nervous people luckily as you saw at the beginning everything went well and we had that perfect launch but that perfect launch was really only the beginning for us because as soon as the cameras Switched Off and everybody went back to celebrating Christmas our team began the Nerf wrecking sequence of unfolding weapon space I say nerve-wracking because it involved more than 300 critical mechanisms so-called single point failures as the name implies each and every one of those had it not worked exactly as planned could have cost us the mission that's why those first few weeks were named the 30 days of Terror for the web mission but as you may have guessed from the fact that I'm here today talking to you about it it all worked just fine we then I vividly remember the day we got the first test image from the fully aligned telescope we had pointed web at just a simple star to make sure we understood the performance of the telescope and that we did everything right the image that came back to us blew us all away I show it here it is the very first image of the telescope and it shows that bright star in an amazing sharpness much sharper than we had even hoped for in addition we saw all these bright spots in the background and when we realized that these were faint distant galaxies that you know some of them the size of the Milky Way and some of which we didn't even know existed after only a few minutes of integration time we saw all this detail that's when we knew we had built ourselves a really revolutionary new Observatory so let me finish with showing you some of the results that web has produced since that early commissioning phase let's start with something nearby the planets of our own solar system this is Jupiter with its intricate Cloud patterns and stunning auroras at the pole a little bit further away we have Uranus with its wispy rings and moons that we never really before saw it infrared wavelengths we young star-forming regions in the Milky Way and nearby galaxies where young clusters of stars blow away their cocoon of dust and gas in which they formed now Illuminating that same gas in the variety of colors and temperatures under the right conditions that gas can be compressed again and collapsed again and form a new generation of stars like here in the famous Pillars of Creation where with web we can really go deep into the dust and see for the first time what's happening in there nearby spiral galaxies and their intricate patterns of clouds and dust and spiral arms that feed the very center where often a black massive black hole is lurking these galaxies can form clusters and groups and merge and Collide setting off spectacular fireworks like you see in this image here and finally we come to the countless galaxies at the edge of the universe whose light has traveled to us over billions of years just to give you an idea of the scales this the area that this image shows you can cover it with just a single grain of sand between your fingertips if you hold it at arm's length that's how many galaxies are in that tiny area but these images they are not just beautiful they contain truly new information that nobody has ever seen before because we've never before been able to study the universe at these wavelengths with this sensitivity and in this detail everywhere we look we scientists we find new things that we need to digest and understand the title of today's event is living on the edge and I think web very much fits the bill because it has pushed the boundaries of our engineering capabilities it has already and will continue to expand the limits of a scientific knowledge in some sense Webb is staring at the edge the edge of space and time itself so when Christmas comes around again this year maybe you will all join me in raising a glass to celebrate the first anniversary of a new amazing Eye in the Sky the web Space Telescope thank you so much [Applause]

Channel: TEDx Talks

Views: 1,989

Keywords: English, Exploration, Science, Space, TEDxTalks, [TEDxEID:49484]

Id: sCxfnmrvcws

Length: 16min 57sec (1017 seconds)

Published: Tue Jan 10 2023