Seeing Beyond - The James Webb Space Telescope

since the first astronomers pointed telescopes at the heavens they have sought to see more see farther see deeper space astronomy changed on April 24th 1990 with the launch of the space shuttle Discovery carrying aboard it the Hubble Space Telescope a lot of people think we launched Hubble into space to put it closer to the stars but the real reason lies in that old children's song twinkle twinkle little star we all know that song and it describes a very real phenomenon the Earth's atmosphere both distorts and blocks light coming in from space in space beyond the atmosphere the stars don't twinkle they shine steady and that allows you to get the stunning images we've become accustomed to seeing from Hubble but that wasn't Hubble's only benefit it's also one of NASA's Great observatories these are general-purpose telescopes designed to be able to observe anything and everything in the cosmos there are a lot of observatories in space but most of them are designed to answer one or two specific questions Hubble was built to be as inclusive as possible it was supposed to answer as many questions as you could think to ask at least as far as its design allowed and Hubble succeeded splendidly at that we've seen planet-wide dust storms on Mars we've seen the astonishingly strong and surprisingly variable Aurora's of Saturn we've looked deep into dense star clusters containing pins of thousands to millions of stars we've examined the birth of these clusters as they emerge from the interstellar clouds and we've watched stars die some releasing their outer layers gently into space like smoke rings others forming cosmic butterflies some expiring and tremendous explosions that blast their material across the cosmos expanding for tens of thousands of light years until their remnants ultimately fade away we'd explored the varieties of galaxies some with beautiful spiral shapes and some with vast ellipsoidal collections of hundreds of billions of stars and we've seen galaxies in massive clusters of thousands arranged through space and time this is perhaps the most important image of all has ever taken the Hubble ultra-deep field it shows us galaxies stretched all the way across the universe five six ten billion light-years away this is like that's taken billions of years to reach us in our corner of the universe so we see these galaxies not as they are today but as they were when the light left them like getting a postcard in the mail that's been traveling for a very very long time and in the end we see nothing is that because we've reached the end of the universe know what we've reached is the limit of Hubble's vision as amazing as Hubble has been we've come up against the immutable reality that Hubble can't in fact see everything to carry us farther to step beyond Hubble we need the james webb space telescope like Hubble Webb is a general-purpose observatory and like Hubble Webb will orbit in space giving it the clarity that comes from being beyond Earth's atmosphere the Webb telescope sees infrared light which is visible to the human eye though we still perceive it as heat putting an infrared telescope like Webb in space is going to open entirely new regions of the universe to us to understand this you need a little astronomical background you've probably all heard that our universe is expanding but what you may not know is that as it expands the light traveling through the universe also gets stretched so what started out as visible light and ultraviolet light the two types of light the earliest objects in the universe emitted most strongly is changed it's stretched into another wavelength infrared light if we want to see the earliest objects in the universe we have to see that faint infrared glow so why haven't we done this before well we have we launched the spitzer space telescope which isn't as well known as hubble but has made incredible discoveries of its own with the infrared capabilities of all acts but when it comes to resolution Spitzer's images are a lot more like ground images than they are like Hubble images to get Hubble quality images in infrared light you need something more we need a giant mirror Spitzer's mirror is just over two and a half feet across Hubble's mirror is about eight feet across so that's about a bit taller than a human being and Webb's wheel uses 18 hexagonal mirror segments to create a reflective surface more than 21 feet across almost two stories talk clearly that's pretty big how do we get something that size into space obviously we can't ship it like this the answer is origami we're going to fold web up inside the rocket that launches it into orbit once it's in space it starts to unfold the massive mirror opens up it's tennis court sized Sun shield which will protect it from unwanted infrared emissions from the Sun Earth and Moon stretches out and all this happens while it travels approximately a million miles away to a point farther away from our planet than even the moon so what are we going to get for all this effort we are going to be able to see past all these galaxies in the Hubble ultra-deep field we're going to be able to see beyond even the most distant red dots and these images the tiny newly formed galaxies at the very edges of Hubble's vision we are going to see the most distant and earliest galaxies in the universe the first stars and galaxies to form after the Big Bang we call these objects the universe's first light Hubble has been able to observe the adult teenage and child galaxies of the universe Webb will see the toddlers and infants filling in our story of galaxy formation and evolution as surely as adding missing photos into a family album reveals how humans grow and change over time but this isn't the only area where we know Webb will provide breakthroughs this is Hubble's image of the Eagle Nebula the famous pillars of creation photo inside these pillars of gas and dust new stars are forming but we can't see them because the dust blocks visible light but it doesn't block infrared anywhere near as well infrared light can beam through the nebula and if we can see it we can see the newly formed stars within Hubble's view of the Orion Nebula shows hundreds of newborn stars only a couple million years old but if we zoom in on Spitzer's infrared image we see thousands more hidden inside Orion is the place where we get the best view of not just star formation but also of the new solar systems forming around those stars we know that planets new Earth's new Saturn's new Jupiter's are forming inside these dark dust rings what we call interplanetary disks we can't see them they're hidden behind a dust webs infrared vision will allow us to see through these opaque clouds so we can discover how solar systems like our own came into be we will be able to see what our own solar system would have looked like after the Sun had formed but before earth existed and Webb's vision is going to take us even farther than that two individual planets beyond our solar system this isn't one of Hubble's most dazzling images but it is an important one several planets are orbiting around this star but their light is lost in the bright glare of their Sun if we can remove the star's light we can see the planets these bright dots you see here this is an infrared observation planets which don't shine with their own visible light are usually brightest in an infrared the best way to observe planets is with a high-resolution infrared Space Telescope a web will be able to take even that another step further some extrasolar planets from our point of view pass in front of their stars when that happens some of the star's light passes through the planet's atmosphere we can analyze that light and measure things about the atmosphere of that distant world so what does that mean for us well here is the plotted infrared light of three different planets you're seeing the differences in those planets that indicate the presence of carbon dioxide ozone and water these are the telltale differences between Venus Mars and Earth the first signs of life elsewhere in the universe will not be photographs of civilizations or a visit by little green men it will be features in the atmospheric spectrum of an extrasolar planet that show biological activity and that's what web has the potential to give us that tremendously exciting discovery so when is all this going to happen when it is scheduled to launch in 2018 just six years away an enormous amount of the work on the telescope has already been completed all of Webb's 18 mirror segments have been ground polished coated and tested it's cameras and other instruments are nearing completion or in their final stages but since Webb will be located a million miles away it has to be perfect before it launches so we're testing everything the pieces get tested separately then together then as part of the actual telescope they're tested to make sure they work in the extremes of space and that they can survive the violence of launch when it's time to test them as part of the entire telescope they're brought to NASA's largest test chamber this cavern like thermal vacuum chamber at Johnson Space Center which is being beheaded especially for Webb if it looks familiar that's because it's famous for being used to test the Apollo space vehicles it seems fitting that that chamber used to prepare humanity for its first true exposure to the heavens is also where NASA's next great space observatories coming together every decade astronomers conduct a survey to determine the astronomy community's top priorities Webb is their number one priority this is the observatory they want above everything else we've already explored some of the reasons why but not the most important reason if Hubble is any guide Webb's most important contributions to our understanding of universe will probably surprise us because it was designed as a general purpose observatory it is extremely versatile the Webb Space Telescope will be able to answer the questions we have and then move on to questions that we haven't yet thought to ask for example before Hubble we thought the expansion of the universe was slowing down but Hubble made crucial discoveries to confirm that actually it's speeding up and for that to happen there may exist some form of strange dark energy this discovery wanted scientists the Nobel Prize in Physics this year the universe doesn't always work the way we think it does it surprises us again and again we've only begun to chip away at the mysteries that are out there and web because it's designed for this purpose we'll be able to explore confirm or deny these discoveries as they arise and that is the true power of web its potential for unbounded discovery its ability to reveal wonder if we didn't even know existed that capability perhaps more than anything else makes web at future of space is problem you you

Channel: James Webb Space Telescope (JWST)

Views: 628,674

Rating: 4.8214469 out of 5

Keywords: jwst, webb, james webb space telescope, telescope, nasa, hubble, hubble's successor, space

Id: 073GwPbyFxE

Length: 14min 3sec (843 seconds)

Published: Fri Mar 22 2013