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  • When you look up at the night sky, you're only seeing a tiny fraction of the estimated

  • septillion stars out there in the universeand honestly it's not your fault. Even astronomers

  • have a hard time. But now the James Webb Space Telescope may

  • just make things a lot easier and push the very limits of infrared light observation

  • to travel back over 13 billion years ago for a glimpse of our universe's first light.

  • So first, what exactly is infrared light? Well, we can't see it, but we can feel it

  • as heat. On the electromagnetic spectrum, Infrared

  • lies right outside of the visible light section, as longer, redder wavelengths. You've probably

  • seen infrared light used in remote controls and even temperature guns commonly found during

  • the COVID-19 pandemic. But for astronomy, infrared light seems to

  • excel in revealing the unseen. Since the beginning of the universe, physical

  • space has been in a constant state of expansion. Although stars and galaxies both keep their

  • size, the shape and space between them continues to expand.

  • And as light travels through the ever growing reaches of space, it is stretched to longer

  • and longer wavelengths. So some of these wavelengths we as humans can actually see,

  • as long as it falls along the visible light region, in what's known as ourwindow

  • of visibility”. Any wavelength extended beyond or falling

  • short of that region is effectively invisible to us.

  • And because of the estimated age of the universe, most of the light from our oldest stars actually

  • lies beyond the visible region since it has been constantly expanding for billions of

  • years. This is known as Cosmological Redshift. Infrared technology allows us to look back

  • to these oldest stars, all thanks to the unique ability of longer wavelengths to pass through

  • dense clouds of cosmic dust. Shorter wavelengths are usually blocked by these clouds, hindering

  • astronomers' studies of the universe. And this new technology exposed infinite possibilities

  • of study. Even encouraging the launch of the first infrared observatory in 1983, the Infrared

  • Astronomical Satellite, which completed a full infrared survey of the sky. And by 1998

  • had helped usher in the identification of hundreds of thousands of new objects which

  • were previously unseen. This led to other infrared discoveries like the largest ring

  • around Saturn and identifying one of the furthest supermassive black holes ever discovered.

  • Now astronomers and engineers are pushing this science to the limit once again with

  • the highly anticipated Webb telescope. The observatory hosts four scientific instruments

  • and two detectors on board, allowing it to study near-infrared and mid-infrared wavelengths.

  • The Near-infrared camera hosts on-board coronagraphs

  • that can hone in on very faint objects even if they

  • are near extremely bright lights, similar to how you would hold your hand up in front

  • of the sun to see another object. Then there's the Near-Infrared Spectrograph, which has

  • a unique technology to analyze the spectrum of an object using a micro-shutter array.

  • This contains 100 microshutter cells, measuring as wide as a human hair. This technology reveals

  • physical properties of a target including chemical composition, mass, and temperature.

  • Next up is the Mid-Infrared Instrument which will use its on board cameras and you guessed

  • it, mid-infrared light to provide amazing imagery, even more impressive than that of

  • the Hubble Space Telescope. And finally the Fine Guidance Sensor/Near InfraRed Imager

  • and Slitless Spectrograph will accurately find targets, investigate exoplanets, and

  • detect first light within star systems. Using these instruments, Webb's goal is to observe

  • early light in the universe over 13 billion years ago, essentially peering back in time

  • to help piece together how the universe shifted from a state of helium and hydrogen to the

  • complex worlds we see today. And what's really cool is that it's a

  • huge international collaboration between NASA, European Space Agency and the Canadian Space

  • Agency. This next generation observatory is a nod

  • to our endless curiosity as human beings to know more about how it all began. So now the

  • fun part begins and I can't wait to see how our hard work has paid off when we get

  • those first images back... So what are some of your biggest questions

  • about the Webb telescope? Let us know in the comments below and make sure to subscribe. Thanks for

  • watching Seeker and I'll see you next time.

When you look up at the night sky, you're only seeing a tiny fraction of the estimated

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Why James Webb’s Infrared Vision is a Gamechanger

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    Summer posted on 2021/10/13
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