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| James Webb Space Telescope |
Intro
Humans have always been strangely curious. Literally about everything! Curiosity keeps us motivated, and enables us to do incredible things. We are born curious: we are explorers. We always want to know more about the place we live and who we really are. This is how Columbus found America. This is how Neil Armstrong was able to walk on the moon. That's how we were able to conceive, design and ultimately launch the James Webb Space Telescope, the most incredible space telescope ever built. We created it because we want to know what came before us.
Because we want to know what happens next. And because we're insanely curious about what's going on right now, while we're alive here, on this apparently normal planet called Earth, and nowhere else. This telescope is already history. And it will become a fundamental piece of the puzzle of humanity. But is it really this basic? What are its characteristics? What has it discovered so far? And what can we expect from it? And there's a reason for that. First of all, our scriptwriters are excited to talk about this amazing engineering miracle; second, seem to be very responsive whenever we talk about Webb.
This is really cool. James Webb has summoned us here to enjoy another video. Webb was first designed and conceived in the 1990s, and the original project estimated it to cost something like a billion dollars. It's a lot amount of money, isn't it? But it is actually nothing compared to the final cost. Let me tell you. If everything worked out well, James Webb was expected to launch in 2007. The thing is, building a telescope from scratch is no picnic, and numerous delays and setbacks haunted the project: it was like James Webb was a cursed telescope! But in December 2021, 13 years later than expected, it finally launched. Now it is operational, and it is orbiting around a point in space, called the L2 lagrangian point of the Sun-Earth system.
In order to be operative, this huge 6500 kg monster, had to spend some months unpacking itself; testing some hardware, and checking that everything was working properly. NASA had some problems on the way, but still, James Webb is working better than expected: it is an undoubted success for NASA and the whole world.
People all over the world have at least heard of JWST and its incredible power. But what can it actually do? James Webb is equipped with a sun shield whose 14x21m dimensions are around the size of a tennis court, in order to keep vital parts of the instrument cold. And its mirror for capturing light is 6 times larger by area than Hubble’s primary mirror.
Without a mirror, a telescope can’t function. And the wider the mirror, the more light the telescope is able to collect. In technical terms, a wider mirror allows the telescope to pick up more photons from further away to create beautiful and accurate images.
James Webb was equipped with a lot of cameras and ultimate generation scientific instruments, in order to boost its performance in the infrared spectrum of light. Basically, James Webb doesn’t see the universe the same way we do. With its characteristic instrumentation, it can explore the universe in more detail, searching for something unusual, unexpected, and maybe never seen before.
Scientists wanted Webb to be sensitive to infrared light and they had a handful of reasons to do that. For instance, we know from physics that due to the expansion of the universe. But this is not the only reason to go for infrared light.
Another one is that the long wavelength part of the light spectrum doesn’t get absorbed so much by the clouds in the universe, while the optical part does. If we were looking through clouds of gas and dust in the optical domain, we wouldn’t be able to see most of what’s behind them. This is because optical light gets blocked by clouds. Nevertheless, the infrared part is free to move through them. Therefore, if we are able to build an instrument that detects infrared light, we can unveil what lies behind these giant clouds. Basically, infrared is better at punching through clouds and other debris. Here’s what James Webb can actually do.
Here's What James Webb Can Actually Do..
Let’s start with our own galaxy. The first object to talk about is a place known as the cosmic cliffs. This landscape of "valleys" and "mountains" is dotted by bright stars that are actually a star—the edge of a young, forming and nearby region called the Carina Nebula NGC 3324. What’s amazing about this image is that it reveals for the first time previously invisible areas of star birth. The tallest "horns" in this image are about 7 light-years high.
The cavernous region has been carved out of the nebula by intense ultraviolet radiation and stellar wind from the very massive, hot, young star at the center of the bubble. Those are newborn stars! This image was already taken by Hubble, but Webb reveals emerging stellar nurseries and individual stars that are completely hidden in visible-light pictures.
Southern Ring Nebula
And now, let’s look a tiny bit closer to home at NGC 3132, also known as the Southern Ring Nebula. This is actually a hot, dense white dwarf star. As it transformed into a white dwarf, the star periodically ejected mass and, as if on repeat, it contracted, heated up, and then, pulsated. The bluer star at the right helps stir up the ejected material. The disc around the stars is wobbling, shooting out spirals of gas and dust over long periods of time.
Webb captured this scene in mid-infrared light — most of which cannot be observed from the ground with a normal telescope. The image on the left was taken by JWST’s Near Infrared Camera (NIRCam), while the one on the right was taken again by Once again, compare this with Hubble’s image and take a moment to appreciate the increasing detail Webb offers us. Are you ready now? We are about to leave our galaxy behind. Take a moment to stare into thousands of never-before-seen young stars in the Tarantula Nebula, 161.000 light years away from us.
Tarantula Nebula
The James Webb Space Telescope reveals details of the structure and composition of nebulae, as well as dozens of background galaxies. Stellar Nursery 30 Doradas got the nickname Tarantula Nebula from its long, dusty filaments. Located in the Large Magellanic Cloud galaxy, it is the largest and brightest star-forming region near our own galaxy, also home to the hottest, most massive stars.
In the longer wavelengths of light captured by its Mid-Infrared Instrument (MIRI), Webb focused on the region around the central star cluster and revealed a different view of the Tarantula Nebula. In this light, the cluster's young, hot stars fade in brightness, and the burning gas and dust rushes forth. Why is this nebula interesting to astronomers? Unlike our Milky Way, the Tarantula Nebula is forming new stars at a tremendous rate.
Although closer to us, it resembles a massive star-forming region since the universe was only a few billion years old, and star formation was at its peak—a period known as the "cosmic noon." Because tarantulas are so close to us, they are easy to study in detail to help us learn more about the universe's past. Hey, if you enjoy this video why don't you subscribe and click the notification bell? Thank you! But hold your breath now, because I'm going to show you something that will blow your mind.
The first deep domain of the web
This fantastic image is the size of a grain of sand held at about arm's length, a tiny sliver of the vast universe. It's really very small, but if you look carefully you can basically see a bunch of galaxies. And if it is a grain of sand, imagine how many countless galaxies there are, and how many stars, how many planets, and how many Earths there are. It's incredible if you think about it, even for a second.
The combined mass of these galaxy clusters acts as a gravitational lens, magnifying more distant galaxies, some of which were seen when the universe was less than a billion years old. This is the so-called "web's first deep field" taken by the web's near-infrared camera (NIRCam). It's actually a composite made from images from different wavelengths, totaling 12.5 hours - reaching depths in infrared wavelengths beyond the Hubble Space Telescope's deepest fields, which takes weeks.
What you notice in this image is the galaxy cluster SMACS 0723 because it appeared 4.6 billion years ago, with many other galaxies in front and behind the cluster. It took billions of years for the light from this galaxy to reach us. It is one of the most distant images of our universe. It's basically looking at a picture of the cosmos when it was younger.
That's the beauty of astronomy: we can observe the past from the present. Unprecedented! This distant light was amplified by the expanding universe at infrared wavelengths that the web was designed to observe. But why the arcade in this field? As we said earlier, the strong gravitational field of a galaxy cluster bends light rays from more distant galaxies behind it, just as a magnifying glass bends images.
Pictures like this give me goosebumps. Among other things, James Webb will search exoplanets for signs of life and help understand both an old galaxy like ours and young galaxies formed just after the Big Bang when the universe contained only hydrogen, helium and lithium. New incredible discoveries are just around the corner. We just have to wait a while. The web will do the rest.
What do you think about James Webb? Let us know in the comments below!