The True Scale of the Cosmos Beyond Our Earth Free Documentary Space

Five years after opening its eye to the cosmos, the Hubble Space Telescope set its sights upon a seemingly empty patch of sky near the constellation Ursa Major. Staring into the void for ten days, the telescope captured 342 images in ultraviolet, visible and infrared light. The compilation revealed a sea of galaxies stretching across time, back to their very origins. Humanity glimpsed the true scale of the cosmos. The invention of the telescope revealed our universe and repositioned the Earth within it. That cosmic perspective shifted dramatically. The universe suddenly became this vast place, populated by galaxies like our own Milky Way. In the 20th century, our telescopes escaped the limitations of Earth's atmosphere. Once we had sent the first satellites into Earth orbit, we had the possibility of sending observatories out into space. The electromagnetic spectrum unlocked a realm of invisible light. Every time we do a new survey at a new wavelength, we always find major discoveries. We're looking right through the dust, and we can see how the stars are being assembled, how they are growing. With next-generation optics, we hope to define our place within the cosmos. Every discovery we have made has changed the way we see ourselves. We should be proud that we can have cosmic humility. For thousands of years, humanity looked to the night sky in wonder. But with only the human eye to observe it, our perception of the heavens was flawed. When the ancient people looked into the night sky, they saw that the stars were arranged in a fixed pattern, and it just rotated around the observer. Aristotle emerged as perhaps the most prominent voice of Greek philosophy, and he coined that phrase of the immutable heavens where nothing would ever, ever change. Many of the ancients pictured a geocentric universe, our Earth at the centre and the celestial bodies in orbit. But not all. Early thinkers in ancient Greece, Aristarchus, had suggested that perhaps the Earth might not be at the centre of the universe and that maybe the Sun might be at the centre. In the 2nd century CE, Hellenistic astronomers devised a model to explain the complex movements of the planets the eye could observe. Occasionally, but regularly, each wanderer's path would briefly appear to move backwards. With Earth fixed as the centre of reality, these retrograde motions were explained by adding epicycles to the planets' orbits. All of astronomy was fixated on the concept that a circle is a perfect geometric figure. And in order to keep circles as the fundamental way that things moved in the universe, they had to put little circles orbiting around bigger circles. Several astronomers would question the paradigm over the centuries. Then, in the 1500s, a Polish canon founded the heliocentric revolution. Nicolaus Copernicus realised that the motions of the planets that we could see in the sky would be much more elegantly explained if they were all moving around the Sun instead of around the Earth. Copernicus was able to simplify Ptolemy's picture and remove many of the epicycles. It turns out, in the end, his circular orbits weren't exactly the solution. At the turn of the 17th century, German astronomer Johannes Kepler did away with circular orbits and epicycles, allowing each planet to orbit in an imperfect ellipse around the Sun. You now had a very simple, direct and clean model for how the solar system worked that mapped with reality. Just a few years later, humanity acquired clear scientific evidence that Earth was not the centre of the universe, thanks to pieces of precisely shaped glass. Astronomy is only as good as the instruments you have. The invention of the telescope in 1608 revealed the heavens. Before the first telescopes were developed, human beings could only see about 3,000 stars. When people first started looking at the sky through telescopes, it was the first time a human sense had been extended. It's a really simple invention, really. Suddenly, you could collect more light and still direct it into a human eye. It uses a couple of lenses. You put them together and you can magnify the objects that you're looking at. You could suddenly stop building astronomy around just points of light in the sky, which is what it had been all about before that. Galileo Galilei was the first person on record to point his telescope skyward. He was able to make out the cratered surface of the Moon and illustrate its phases in detail. Galileo then trained his sights on Venus and discovered that it too went through phases. He showed that the Milky Way was basically made up of stars rather than some sort of coagulated milk. He showed that there were mountains on the Moon and craters on the Moon. But perhaps his greatest discovery came as he observed the planet Jupiter. He was looking through his telescope and he saw what he thought were four stars around Jupiter. He kept watching the stars over the course of a few days and he saw those stars rotating. And so he published his discovery as the moons of Jupiter. It changed the concept in the minds of astronomers that the Earth needed to be at the centre of the universe. Telescopic sight had revealed a distant world with its own satellites. However, the telescope's ability to open up our universe had only just begun. A clear night reveals that the stars are not randomly sprinkled across our sky. Most collect in a long, dense trail sweeping through the heavens. This milky path that stretches across the sky, which the Romans have called Via Lactea, the path of milk, and we call it today the Milky Way. It's an amazing sight, but you can't distinguish all of the individual stars. The Milky Way is really a collection of many billion stars which are individually too small to be seen. While Galileo's telescope revealed the individual stars, the Milky Way's significance would not become clear until the late 18th century. The brother and sister team of William and Caroline Herschel constructed some of the largest telescopes in the world. There are different types of telescopes. Either you can use lenses which are made of glass, and you pass the light through the glass. These are called refractive telescopes. There was a natural limit to how large you could make these telescopes based on lenses. When you make a lens larger and larger, it becomes pretty heavy. That piece of glass bends under its own weight, and it loses the perfect shape to which it has been manufactured. In 1789, the Herschels completed the world's biggest telescope, 12 meters in length. The great 40-foot telescope captured light not with glass but with polished metal. Mirrors you could make much larger without structural problems because you could put a piece of steel underneath that would hold them in place and that was structurally much stiffer than a lens would ever be. Also, they don't suffer from some of the problems or what we call in the business aberrations that the glass lenses do. In the 1780s, Herschel and his sister embarked on a project to map the Milky Way. Conceptually, it's quite difficult these days to think about just what an endeavor this was. These were two people looking out with a very large telescope that they'd built themselves, mapping a forest from being within the forest. You don't really know what it looks like from outside. They measured the distances to what they called nebulae at the time, and what they found was that these nebulae were actually usually clusters of stars. And Herschel assumed that every star would have the same sort of true brightness, the same amount of light it emits. So he figured if I just look into all directions in the sky and I count how many stars I see there, I could work out the structure of the Milky Way, that overall distribution of stars. It wasn't a correct assumption, but it wasn't a bad one either, because scientists in the face of a lack of knowledge, a lack of understanding, have to start somewhere. Knowing the exact point at which their telescope was pointed, and calculating a star's distance based on how dim it appeared, the Herschels slowly mapped the structure of the Milky Way. They discovered that the Milky Way is like a flattened disk shape, and the stars were not distributed uniformly across the whole of the sky. In spite of their hard work, the Herschels incorrectly concluded that our solar system was near the centre of the Milky Way. Their sample of stars was too limited. The Milky Way consists of much more than just stars. There are heaps of dust clouds, and they are so dense that they obscure the light from the stars. The Herschels were limited by the most nearby dust clouds surrounding us, and that's how far they could see. It would take over a century to reposition our home. As the 20th century dawned, the next record-setting telescope was completed. 22 tonnes of moving parts, supported by a pool of liquid mercury, to turn a gigantic mirror toward its targets. The power of the 60-inch telescope in Southern California allowed astronomer Harlow Shapley to embark on his study of globular clusters. Bound collections of stars that evolved from the same gas cloud. You might think about it like a gigantic ball containing tens of thousands or even hundreds of thousands of stars. Crucially, they are not in the plane of the Milky Way, but a sphere all around the centre. You can see these clusters above the plane of the Milky Way, below the plane of the Milky Way, where there is no dust in the way that blocks your view. Shapley employed a certain breed of star within these clusters to determine their distance from Earth. It's really hard to measure distance in space because we can't just get a ruler and place it between the stars. But it's a really important part of what we do. One of the best ways to discover how far away things are is to look at a type of star called a Cepheid variable. Like cosmic clockwork, Cepheids vary their brightness over time. And it's a stable pulsation where each pulsation might last for a week or up to a month. Shapley knew that he could time those pulsations and derive the distance. So you can take the Cepheid variable star, put it far away, and the light gets dimmer. But we know what the brightness is because we know how it's pulsating. The dimness tells us the distance. Calculating the distance of Cepheid variables, Shapley revealed that just as our Earth is not the centre of our solar system, our solar system is not at the centre of the Milky Way. We now know, in fact, that the Earth and the solar system are closer to the edge of our galaxy than to the centre. About 25,000 light-years from the centre of the galaxy. In 1917, the 60-inch telescope at Mount Wilson was surpassed by a new device at the same site. Weighing over four tonnes, the 100-inch Hooker telescope's mirror was forged from wine bottle glass, coated in reflective silver. American astronomer Edwin Hubble was offered a staff position at the observatory and soon set to work studying spiral nebulae. There was a big debate about the nature of the nebulae. One party said, they are just glowing gas clouds. And the other side said, we think that some of them might be whole Milky Ways or whole island universes. To settle the debate, Hubble measured their distances from Earth. He thought they were outside the galaxy, but other astronomers thought they were within the galaxy. In October 1923, while comparing separate photographs of the Andromeda Nebula, Hubble identified a Cepheid variable star. His calculations showed that it was 900,000 light-years away, far beyond where Shapley placed the edge of the Milky Way. It meant that Andromeda couldn't possibly be part of our own Milky Way galaxy. It had to be a separate galaxy, a separate island universe. This was the moment when the Andromeda Nebula became the Andromeda Galaxy. We were no longer the centre of everything. The universe suddenly became this vast place, populated by galaxies like our own Milky Way. Hubble's follow-up discoveries swiftly convinced the great majority of astronomers that the universe contained a myriad of galaxies, perhaps as many as 100 billion. The universe was far bigger than we could possibly have imagined. Every discovery we have made has changed the way we see ourselves in relation to this universe. We become a smaller part of it. We become a less privileged part of it. We're on a tiny rock that's orbiting a very average star. And that star is one of 200 billion or so orbiting a pretty ordinary spiral galaxy. And that's in a group of about 50 galaxies within a supercluster of probably millions in a universe that is unimaginably big and possibly completely infinite. But to truly explore the universe, we had to see the invisible. Before the 19th century, humanity's view of the world was restricted to the visible spectrum. Then, in 1800, William Herschel, the same man who attempted to position our Sun within the cosmos, exposed sunlight's secret. Herschel knew that Newton had split the light of the Sun into the rainbow of colours. He then wondered what would happen beyond that rainbow of colours. He was interested in what temperatures the different colours of the rainbow might have. But then, out of interest, he moved one of his thermometers beyond the red edge of the spectrum and discovered that the temperature there was higher even than the hot red end of the spectrum. And that told him that there was some form of radiation which may have been similar to the radiation of light, but it carried with it heat. And that was actually the discovery of infrared radiation. He went on to be able to show that these infrared rays were the same kinds of rays as the visible light. They were reflected and refracted. These rays of energy traverse and disperse across the vacuum of space. But they are merely two sections of a continuous spectrum from radio waves at the lowest energy to gamma rays at the greatest. And that really set the stage for a detailed understanding of the broader electromagnetic spectrum. Astronomers were slow to adopt technology capable of detecting these rays. But following technological developments spurred on by the Second World War, the field of infrared astronomy blossomed. Infrared light, we can't see it with our eyes, but our detectors, our cameras at the telescopes can actually capture that light. Infrared astronomy was a massive breakthrough because it allowed us to see through dust. The star-forming regions where young stars are just forming are engulfed in dust. When we use infrared light, we're looking right through the dust, which is transparent to infrared, and we can see how the stars are being assembled, how they are growing. We've never been able to watch true infant stars before the advent of infrared imaging. The entire electromagnetic spectrum eventually became accessible, with each band revealing different secrets of the universe. Our eyes are evolved to detect visible light, but that's really only a fraction of the whole electromagnetic spectrum. When we're looking at the UV, we're actually looking at the stars and the hot gas. When we're looking at the radio, we're looking at the cold gas in the universe. Each band of electromagnetic radiation is uniquely challenging to study, even visible light, as our ground telescopes are hindered by the very air humanity needs to survive. On Earth, we're very, very fortunate to have an atmosphere. For astronomers, that's not so good. As light comes from a star, it's travelling in a straight line, but then it gets perturbed through our atmosphere. This is why stars twinkle. If you take an image of that, it just comes out blurred. In order to limit the volume of atmosphere that we need to peer through, the largest optical telescopes in the world tend to be built on the tallest mountains. Today, astronomers and engineers combat atmospheric distortion with technology known as adaptive optics. Adaptive optics is a technique that was proposed back in 1953. At that time, the technology wasn't there to actually implement this idea, but in the late 70s, early 80s, people started thinking about how they could do that. To counteract distortion, astronomers shoot powerful lasers into the sky. We use a technique called laser guide stars. What you do is you propagate a laser beam into the night sky and you create an artificial star with it. The laser hits sodium atoms on the edge of the atmosphere, causing them to glow. The light travels down through the turbulent air and a telescope receives its point of reference. Computers analyse the distorted artificial star and create an inverse pattern. That pattern is sent to a deformable mirror, which uses magnets to bend it into shape. And we push and pull on the surface with little actuators in the back. It's like a bed of nails, and they're like fingers, which can move and distort it in a way which compensates for the errors introduced by the atmosphere. Because particles in the atmosphere are constantly shifting, these adaptive mirrors have to adjust in real time, up to a thousand movements per second. The distortion is cancelled out, revealing how the heavens appear before entering Earth's air. And sometimes you can't even tell the difference between images that have been captured on Earth with adaptive optics and those that have been captured in space above the atmosphere entirely. In 1995, the technology enabled the discovery of the very first brown dwarf, the missing link between the largest planets and the smallest stars. By resolving individual stars and tracking their motions at the heart of the Milky Way, adaptive optics was also employed to identify the presence of a supermassive black hole. But to truly unlock the heavens, we would have to journey to them. Our atmosphere not only distorts images, it also prevents some light from ever reaching our eyes. We do some amazing observations of the universe from the ground where we can, but really the Earth's atmosphere blocks critical wavelengths. Very high energy gamma rays, infrared, ultraviolet, the whole range. The view from Earth's surface is insufficient if we truly hope to understand the universe. It's kind of like if a doctor was trying to diagnose you and he only looked at one part of your body instead of your whole health. The solution would be difficult, but necessary. We needed to deliver a telescope to space. The more than two tonne OAO spacecraft is this country's heaviest unmanned satellite. It will carry nine telescopes. Once we had sent the first satellites into Earth orbit, we had the possibility of escaping that atmosphere and sending observatories and instruments out into space to gather data without having to go through the Earth's atmosphere. On December 7th, 1968, just three weeks before the first crewed flight around the Moon, an Atlas Centaur rocket carried the first successful space telescope into orbit. Orbiting Astronomical Observatory No. 2 earned the moniker Stargazer. It was put up by NASA and it was a UV telescope. What Stargazer did was it looked at many, many, many stars and it actually told us that stars are hotter than the models had been saying they were. Astronomers have long believed that new stars are formed by the condensation of interstellar gas and dust. With the OAO, we may be able to better understand the process of star formation. The observatory also confirmed that comets are surrounded by vast clouds of hydrogen. But most importantly, Stargazer proved the viability of an observatory in orbit. With each subsequent decade, new telescopes were carried to the heavens, opening up the electromagnetic spectrum. Everything on Earth emits infrared radiation. Our bodies do, the Earth does, the atmosphere does, because it's all being heated by the sun's rays. And so we often have to get our infrared telescopes out into space. The Infrared Astronomical Satellite, a joint project between the US, UK and the Netherlands, launched in 1983. It is a new window into astronomical observations and opportunity to learn new things about the stars. Every time we do a new survey at a new wavelength, we always find major discoveries. And those discoveries are almost never what we intended to find in the first place. IRAS mapped 96% of the sky over its 10-month mission. It pierced the dust of stars that had just erupted. And revealed the Magellanic Clouds, satellite galaxies of the Milky Way, located about 190,000 light-years away. But humanity's longest-serving infrared space telescope is NASA's Spitzer. Launched in August 2003, Spitzer entered service as the year came to a close. Spitzer was the first telescope placed in an Earth-trailing orbit, circling the Sun at the same distance as Earth, slowly drifting away from the planet over time. This allows it to stay much colder, because it doesn't have to deal with the glow emanating from Earth itself. And by keeping the instrument colder, you really reduce the background noise and you can see much fainter signals. Peering through dust, Spitzer revealed Saturn's outermost ring, Phoebe, which starts about 6 million kilometres beyond the planet. Hidden cradles of newborn stars. And some of the most distant black holes in the Universe. Even when its liquid helium coolant ran out in 2009, its mission continued. The Spitzer team turned around and said, no, we can still operate at some of the wavelengths. It's OK, we don't need the coolant for that. And some of the most amazing stuff that Spitzer has done in those latter years were never predicted in the beginning of its mission. It was so productive right up until the very end. Spitzer was officially decommissioned in January 2020, 16 years after it first opened its infrared eye. However, the juggernaut of space public relations, outreach and monument to humanity's exploration continues to operate. The Hubble Space Telescope. Hubble really capitalized on some of the earlier developments. With the Space Telescope, we'll be able to look to much greater distances and therefore much further back into time, much closer to the creation of the Universe itself. On April 24th, 1990, the Space Shuttle Discovery carried Hubble to its home in Earth orbit. One month later, Hubble was ready to begin its mission. But when the first images were downloaded, something was wrong. Everyone was really surprised and shocked. The image quality wasn't what they were expecting. They were fuzzed out and blurred in a way that really had not been anticipated. Somewhere during the telescope's construction, an error had been introduced. When you build a telescope, whether it's with mirrors or lenses, you first have to take close attention to the shape. The surface has to be polished exquisitely well. Hubble's mirror had been polished a little too flat. The curvature was off by one-fiftieth the width of a human hair. In 1993, after extensive testing and simulations of the repair, the shuttle Endeavour was sent to modify the telescope. Astronauts performed five spacewalks over ten days. It was too difficult to replace the mirror, but because they knew how exactly wrong it was, they were able to counteract that. The analogy I like is put a pair of eyeglasses on all the instruments to compensate for the error. On January 13th, 1994, NASA announced that the new optics were working. Once the Hubble Space Telescope was fixed, then it started to deliver amazing science. The images that Hubble started returning were just striking. We were able to see detail in these distant galaxies that had never before been possible. Layers of atmosphere that stars had expelled maybe 10,000 years ago and that now form very intricate shapes. Hubble also showed us visions of objects in our own solar system that had only been possible previously with space probes like the Voyagers. We were able to see for the first time the changing effect of seasons on Mars, the way that the polar ice caps grew and shrank. Just seeing these scenes made the universe to me more Earth-like. It became like landscape photography. Over its lifetime, Hubble produced some of our most spectacular and iconic images of the cosmos. From the pillars of creation to the sharpest ever view of the Andromeda galaxy and perhaps the most important photograph in astronomical history. On December 18th, 1995, the Space Telescope began a 10-day mission known as the Hubble Deep Field, staring at an apparent void near Ursa Major. It was taking the most powerful telescope of the time and allowing it to stare at what was otherwise an apparently empty patch of sky for as long as we possibly could. Whereas most astronomical surveys were concerned with capturing the full breadth of the sky, Hubble focused on a single location that would not be obstructed as the telescope circled the Earth. The Hubble Deep Field is about the size of a coin. So if you hold up a coin to the sky, that's about the size of the Hubble Deep Field. And what was there was astounding. The resulting image revealed almost 3,000 galaxies. Sharp images of galaxies you could only dream to have seen on a photograph and it revealed just a plethora of different sizes, shapes, colours, ages. We do see other spiral galaxies like our Milky Way, but we also see these giant red elliptical galaxies. We also see galaxies that are in the middle of colliding. It's not just a pretty picture. It reveals things that astronomers just didn't know about the nature of the Universe. Each galaxy in the Hubble Deep Field resides at a different point in time. When we observe galaxies at further and further distances from us, what we're seeing is light that left those galaxies millions or indeed billions of years ago. The most distant are shown as they were over 12 billion years in the past. Hubble provided us a time capsule in a single compiled image. We turned Hubble from a potential failure to what is today the most incredible instrument that humanity has known to this time. The Hubble Space Telescope had a few instruments initially that did a really good job, but then as the technology evolved we were able to retrofit the telescope with even better instruments. Hubble embarked on further deep field missions, peering even farther into the cosmos with updated cameras, providing surveys in both ultraviolet and infrared light. With an almost infinite sea of galaxies, scientists hope that somewhere lies a world like our own. In the 16th century, an Italian friar named Giordano Bruno expanded the Copernican notion of the cosmos. Giordano thought that stars were really far away solar systems of their own. Stars like the Sun that would be orbited by their own planets on which there might possibly be life. Bruno was deemed a heretic and burned at the stake by the Roman Inquisition. But the notion of exoplanets and life upon them did not die with him. One of the most important questions to answer of course is whether we are alone in the universe and that's why astronomers are actively looking for exoplanets. In 1992, astronomers used the Arecibo radio telescope in Puerto Rico to observe a pulsar over 2,000 light years from Earth. A pulsar is a really weird type of a star. It's really the remnants of an old star that's gone supernova and its core has collapsed down into a very, very small, very dense star and it's spinning around very, very rapidly, sometimes more than a thousand times a second and beaming out kind of a lighthouse of radiation. But their particular cosmic lighthouse had some mysterious irregularities. Some object was close enough to regularly exert a gravitational effect on its timing. It turned out it wasn't just one planet but as many as three planets that were orbiting the pulsar and their orbital periods were able to be inferred from those timing measurements. The first worlds beyond our solar system had been found. In 1995, a pair of Swiss astronomers were watching not the core of a dead star but a star very similar to our own. 51 Pegasi, located just over 50 light years from Earth. Its light was periodically getting redder, then bluer. It was also wobbling in space, the movement caused by a smaller body in orbit. While we might not be able to detect the presence of the planet directly, we can detect their gravitational influence on their parent star. The planet was about half the mass of Jupiter but orbited so close to its star that its year lasted less than five Earth days. Many of the solar systems we find have got these hot Jupiters, large planets which orbit very close to their parent stars. They're the easiest ones to find, they have the biggest effect on their parent star and so they tend to be the ones you find first. As the new millennium dawned, a fresh field in astronomy flourished. There have been some amazing discoveries of extrasolar planets, including huge solar systems. And a lot of the planets that we're finding are very big and very close to the stars. So these are enormous sort of Jupiter plus planets, but within the orbit of Mercury. They come in all different shapes and sizes. They're planets that don't bear any resemblance to the distribution of our own solar system necessarily. We're finding exoplanets around binary star systems and we're also finding different sizes of planets around stars. We've even discovered orphan planets, planets that do not have a star to orbit. Where did these come from? Are they things that have been shot out of a solar system by gravity or are they things that formed in space? Some we've even seen directly through infrared telescopes, picking up their heat sources as they dance around their star. But despite all these observations, the Earth remains special. It's easy to say we're unique, you know. We're the blue planet, we've got all this water. We have the most complex life that we're aware of so far. But we don't really know. Our sample of the other planets is actually pretty tiny. The Universe is a largely inhospitable place. The Holy Grail for many planet hunters is the discovery of another world with the potential to support life as we know it. Astronomers are really excited about the idea of finding other Earths in the Universe. We believe they exist. Habitable zones are distances from a given star where liquid water, a key ingredient to life as we know it, can exist upon the surface of an Earth-like world. Joining the quest in 2009, NASA's Kepler Space Telescope led the charge to discover Earth-sized exoplanets in the habitable zone around their stars. If we are to find life anywhere else in the Universe apart from the Earth, having liquid water is probably a good place to start looking. But the habitable zone is not the same for every star. The more massive the star, the brighter and hotter it burns, so the planet must orbit farther away in order to retain water. Kepler's sole scientific instrument was a photometer that continually monitored the brightness of approximately 150,000 main-sequence stars. Incredibly tiny but periodic drops in brightness indicate that a planet is momentarily blocking a small portion of the star's light. Kepler-186f was the first Earth-sized planet found within the habitable zone, over 500 light-years from Earth, in the constellation Cygnus. The rocky world orbits a red dwarf star. If we're looking for planets that might harbour life, we really want them to be around a stable star like our Sun. A lot of the planets that have been found are around red dwarf stars. Now they're very unstable, they're very faint most of the time, but then they have huge eruptions of radiation which would probably kill any life forms on the surface. As of 2020, there are over 4,000 confirmed exoplanets. Over half of those were discovered in Kepler's data. We have discovered thousands upon thousands of planets around stars in the region around our Sun. But this is only a drop in the cosmic ocean. There's no rule that says planets have to be orbiting in the same plane that we are. If Kepler is able to, by chance, detect thousands of exoplanets which just happen to be passing in front of a star, we can then step back and go, wow. There are likely to be tens if not hundreds of trillions of planets just in the Milky Way galaxy. And then if you think of all the trillions of other galaxies in the universe, there would just be an unimaginable number of planets out there with an incredible array of possibilities. Kepler ended its mission in November 2018. But the baton has passed to other observatories, both around the world and in space. So I think as we discover more about the cosmos, we become smaller and less significant. But our significance remains for an important reason. And that is because we are still the only lifeforms known in the universe right here on planet Earth. Humanity's suite of telescopes, from the ground to in orbit, have opened up the cosmic history books. Hubble brought us close to our universe's inception. But to go ever further back, humanity continues to advance our telescope technology. Hubble's successor is the most complex and largest space telescope to date, named after the man who headed NASA in the 1960s, James Webb. It's the biggest telescope we've ever put into space. And it has an unprecedented capability to look into the early universe and look with great resolution at what the galaxies look like in the early universe. Its 18 gold-plated mirrors combine to stretch 6.5 metres across. So it's a significant increase in collecting aperture and it's going to be able to look much deeper and further in the universe. At the height of Hubble's power, it could look back to a tenth of the universe's total age, but not far enough to witness the births of the very first galaxies. James Webb aims to look at the very first galaxies in the universe. We don't know what they're going to look like. We don't know what type of gas they're forming from. Unlike Hubble, which originally studied visible light, James Webb performs mostly infrared observations. It will also see how massive black holes in the universe accrete matter and grow. We know that we have black holes one billion years after the Big Bang, which already have the mass of 20 or 30 billion suns. We don't know how to make them in such a short time. The James Webb Space Telescope operates outside of Earth's orbit, 1.5 million kilometres from the planet, four times the distance of the Moon. There are some very interesting points in space called Lagrange points. Lagrange points are balance between the gravitational forces of multiple space objects. Webb orbits the Sun, but remains in a fixed spot in relation to the Earth. It's possible to locate spacecraft there so that they are always sitting at the same location relative to the Earth and the Sun. It's never going to see Earth. It's never going to see the Sun directly. It's always going to be looking out. It's going to be scanning different areas of the sky. It's looking exactly where we want to, away from the stuff we know, and out into the universe. There, its five-layer solar shield, the size of a tennis court, blocks the light from the Sun, Earth and Moon, as well as heat from the spacecraft itself, enabling Webb to obtain the deepest observations to date. Looking forward, we should prepare for more surprises. In ten years, we'll have a completely different take on how big the universe is, and it just keeps getting bigger and bigger out there. Manipulating light, we have revealed the heavens. The invention of the telescope and then its subsequent improvements absolutely turned our understanding of the natural world on its head. Humanity continues the search for our exact place in the cosmos. Twenty years ago, we only knew of one solar system that had planets. Now, we know of thousands. It's amazing. Centuries of discovery have challenged our preconceptions. The wonderful thing about science, and particularly studying the cosmos, is that our perception is continually changing. Our new generation of telescopes will reveal even more. It's important that we keep pushing the boundaries so that we never become complacent, that we never stagnate. We are constantly challenged by the things we discover and the things we attempt.