Hi, this is Wayne again with a topic “How the James Webb Space Telescope will revolutionize astrophysics”.
Decollage liftoff from a tropical rainforest to the edge of time itself. James webb begins a voyage back to the birth of the universe. Nasa just launched the most advanced space telescope ever created a spacecraft that could fundamentally transform our understanding of the universe. As we know it. It’S the james, webb, space, telescope or jwst for short and while technically it is a telescope, it’s really more like a time machine, one that will allow us to peer back to the dawn of the universe when the first stars and galaxies were just taking shape. The primary science driver was to find the earliest galaxies to find the very first epic of galaxies that were born after the big bay. Amber strawn is an astrophysicist at nasa’s goddard space flight center and she’s been working on jwst for more than a decade.
I really do think that this telescope will will be transformational for astrophysics. I think that we will learn things about the universe that completely surprise us. Jwst is often considered the successor to nasa’s hubble space telescope, a bust-sized observatory. That’S been orbiting the earth for the last three decades. You may recognize some of hubble’s greatest hits with its nearly eight foot long mirror. The telescope has captured some of the most iconic space photographs of galaxies and nebulas ever taken, and it’s also told us a lot about our cosmic home. Hubble is the reason we know that the universe is about 13.8 billion years old. As incredible as hubble has been. You know there are a lot of ways that we have pushed it to its limits, and jbst is specifically designed to sort of go past that boundary and answer some of these big questions that hubble just can’t quite get to. We expect jwst to be roughly about a hundred times more powerful than hubble, but unlike hubble, which sees in the optical wavelengths of light, jwc will see in the infrared. So if you look at the most distant galaxies, we’ve ever seen with hubble you’ll see that there are these teeny tiny, little red dots, they’re so distant, that their light has been stretched by the expansion of space-time all the way into the infrared part of the spectrum. So, in order to have a telescope that would be able to detect these very, very early galaxies, it needed to be infrared, and it also needed to be very. Very big. Infrared is a type of light that we can’t see with our eyes, but we can feel it in the form of heat, any object that has a temperature above absolute zero emits infrared radiation and the hotter. The object is the brighter it glows with infrared light. That’S one of the great tricks of infrared light, as it sort of allows us to peer through dust to see the sights of star formation. This new telescope sports, a giant mirror more than 21 feet across that will gather even more light than hubble’s, and also the size of the mirror helps us to see finer detail in the cosmos in this wavelength range. So thinking about.
If there was a bumblebee on the moon from the earth, we would be able to see that the heat of that bumble bee and in terms of sharpness, we would be able to see details the size of a penny from 24 miles away. James webb’s mirror is coated in an unthinkably thin layer of gold about 200 times thinner than the average human hair gold it turns out is really the best material for reflecting infrared light and a lot of the wavelengths that we care about. It can be as reflective as 98 of all light that hits it lee feinberg is the optical telescope element manager for the james webb space telescope. We also needed a structure large composite structure designed to work at the very cold temperatures of jwst. So that’s minus 400 degrees fahrenheit, but that is incredibly stable. Nasa plans to send jwst into a super distant orbit of roughly a million miles away, which is about four times farther out than the moon, combined with the telescope’s massive mirror.
This means we can peer into the deepest recesses of space and time. Jwst will be able to study objects that are 10 billion times fainter than the stars that we can see without using a telescope, but even more enticing is that jwst will be able to gather light from stars and galaxies located up to 13.6 billion light years away. From earth and that’s what makes the telescope a window into the past, the light from those objects will have taken 13.6 billion years to reach the telescope’s mirror. That means these objects were around just 100 to 250 million years after the big bang. At that time, the universe was just at one or two percent of its current age.
It’Ll be our first time in history, seeing what the earliest galaxies in the universe look like in their infancy. Now right now, um the farthest back in time that hubble can see. Just barely as like, when the universe was 400 million years old, so um, that’s a really exciting aspect of of what jwst can do and that’s just going to uncover things about the universe and about you know, astrophysics that we that we can’t even imagine at this Point scientists first conceived of jwc in 1989. and back in those early days, they underestimated just how much it would cost and how long it would take to build and many of the technologies that were needed to make the telescope a reality like those impressive gold mirrors For instance, just didn’t exist when the spacecraft was first dreamed up. Let’S see we had to invent 10 technologies just to be able to build it.
You know we actually had to make the mirrors, for example, on jwst 10 times lighter per unit area than the hubble primary mirror, just to be able to have the the rocket be able to carry that much mass up so so in just about every way. Jwst is really pushing the envelope. It’S it’s. It’S really nothing like we’ve ever done before. There were plenty of road bumps along the way when it came to piecing the spacecraft together decades later, its total development cost is at 9.7 billion dollars. Meanwhile, as jwst struggled to get off the ground, the field of astronomy continued to blossom and to diversify one emerging field. The study of exoplanets or planets outside our solar system grew into a thriving new discipline. We didn’t even know that exoplanets existed before the 1990s.
Now we’ve discovered thousands of these far-off worlds and hope to discover many thousands, more jwst’s ability to detect super faint light, also means it will be able to catch glimmers from the atmospheres of distant planets and perhaps tell researchers whether those atmospheres contain signs of life. All of this means that thousands of scientists are thirsty to get just a few hours of precious time with the telescope when it’s operational, unsurprisingly, jwst’s first year of science, is jam-packed full of scheduled observations. If all goes well, researchers will have at least five and a half years with webb, with the possibility of extending its mission beyond 10 years. Ultimately, its life is limited by the finite fuel it has on board and how much its components degrade over time. But even though jwst is in space now, everyone is still holding their breath. This telescope isn’t out of the danger zone yet in order to fit on top of the aryan 5 rocket that launched it into space, jwc had to ride completely folded up from the very early stage.
We knew we had to figure out a way to unfold. The primary mirror – and that meant making it segmented in some way, so that kind of drove that and then likewise we knew that we needed a way to cool that mirror and the multi-layer sunshield seemed to be the right way to go. But it needs to be very large so that, as the telescope slows around, we keep the sunlight and really moon and earth light off of the telescope, and so that made this sunshield about the size of a tennis court and we use a very light kapton material. It’S like almost as light as aluminum foil. If you will, we actually can fold it all up and we control it in a very special way and it’s a lot like origami, where it sort of unfolds in different sections and actually, when we’re all done unfolding, it we’ll actually tension it during the unfurling. There are 344 single points of failure.
That means those steps and those mechanisms must work perfectly, or else they could jeopardize the entire system. A lot of the large deployments happen during the first two two weeks or a little more than that. You know most of the team, i think feels like that’s really.
You know they’ll rest after that, but for me personally, actually that’s really kind of when i get started, because that’s only when we start deploying the mirrors which each have these six actuators that push them forward and then we start all the alignments of the telescope. So i won’t actually rest until the telescope is aligned to the primary mirror is what we call phased up as though it’s a single mirror, but if the telescope does unfurl as planned, then the last big test comes 29 days after launch when the spacecraft burns its Thrusters putting it on its orbit 1 million miles out from earth, it’s a lot of moving parts, but it’s all necessary for jwst to work and, unlike hubble jwst, can’t be fixed. There’S no current way to send humans out to the spacecraft to give it a tune-up.
If it’s broken, but if everything goes smoothly, we’ll get the very first images and data from jwst by summer of 2022. That will be when a new era of astrophysics begins, one where we can see into the farthest reaches of the universe, as we know it. If you enjoy this video and want more space coverage, check out, theverge.com and like and subscribe to our youtube channel, .