The world's largest space telescope is about to blow our minds and hearts! James Webb's space telescope will be 100 times more powerful than Hubble's. It will alter our perception of the universe by exposing us to strange new worlds. It will trace the universe's origins and explore the galaxy in search of life. This is not the plot of a new science fiction film, but rather the mission objectives of the James Webb Space Telescope, the Hubble's long-awaited successor.
NASA launched the Webb from French Guiana on Christmas Day 2021, in collaboration with the European Space Agency and the Canadian Space Agency. The telescope must perform a difficult mechanical manoeuvre during its journey: self-assembly. Due to the telescope's size, it had to be launched folded inside a rocket. It must unfold its various components over several weeks, from its sunshield to its mirrors. According to NASA, the mission could be jeopardized by more than 300 potential technical issues, or "single point failures."
However, scientists believe that once fully deployed in space, the Webb will usher in a new era of astronomy and reveal to humanity things it has never seen before. "The Webb is the culmination of decades, if not centuries, of astronomy," says Sara Seager, an Massachusetts Institute of Technology astrophysicist and planetary scientist. "This has been a long time coming."
Going Beyond Hubble Telescope
Even before the Hubble Space Telescope launched in 1990, scientists considered a follow-up. After more than three decades in space, it is unknown how long this boundary-pushing satellite will be able to scan and photograph the universe.
The Webb was originally scheduled to debut in 2010 at a cost of approximately $1 billion. Its cost has risen to $10 billion, and it is long overdue. However, the wait will be worthwhile, according to scientists who anticipate new and illuminating glimpses of our universe.
"With Webb, we're going all the way to the edge of the observable universe," Caitlin Casey, an assistant professor of astronomy at the University of Texas at Austin, explains. "And, yes, we're looking forward to seeing what's there."
The Webb will outperform the Hubble in a number of ways. It will enable astronomers to look not only farther into space, but also further back in time: it will look for the universe's very first stars and galaxies. It will enable scientists to conduct in-depth studies of a large number of exoplanets — planets orbiting stars other than our sun — and even conduct a search for signs of life on them.
The Webb is a complex machine designed to answer unanswered questions about the universe and to explore areas previously unexplored. The Webb's golden mirror represents a quantum leap forward for telescopes of this type.
The Hubble Space Telescope, named after renowned American astronomer Edwin Hubble (1889-1953), was launched on April 24, 1990, marking a watershed moment in astronomy. On Earth, astronomers seek out remote mountaintops and deserts to construct large telescopes in order to observe a dark sky free of pollution and bright lights. However, their view is still obscured by the Earth's atmosphere's slight haze and luminescence. NASA describes space as the "ultimate mountaintop." There is no better view of space than from within it.
For astronomers, Hubble has meant so much over the course of its 30-year existence. For one thing, it has provided us with incomparably beautiful images such as those of the Lagoon Nebula and the Pillars of Creation.
Additionally, it has taught us about the universe's age, what happens when stars explode, and about black holes. It aided in the establishment of a good deal of the boundaries that the Webb hopes to push. Most significantly, its observations have led scientists to believe that the universe is expanding at an accelerating rate, propelled by an unknown force dubbed "dark energy."
The Webb is controversially named after the NASA administrator, James Edwin Webb (1906-1992) during the decade preceding the moon landing. NASA's latest telescope has undisputed technological accomplishments. It is expected to build on the Hubble's success.
"What we're going to get is a telescope about 100 times more powerful than Hubble," says Amber Straughn, a Webb astrophysicist at NASA. The Webb outperforms Hubble in two critical ways.
Larger Size
The first is simply its size: Hubble was roughly the size of a school bus, whereas Webb is more akin to a tennis court in size. "This is a monstrous thing," Straughn observes. "By far the largest telescope NASA has ever attempted to launch into space is Webb."
However, it is not solely the size of the contraption that matters. When it comes to reflecting telescopes, the curved mirror's size is critical. "You could consider a telescope mirror to be similar to a light bucket," Straughn says. The more light you collect in this bucket, the fainter and farther-flung objects in the universe become visible.
Hubble's mirror had an impressive diameter of 7.8 feet. Webb's stunning, gold-hued mirrors combine to form a 21.3-foot-diameter circle. That is more than six times the light-collecting area in total.
In practice, what does this mean? Consider the Deep Field, one of Hubble's most famous images. In 1995, scientists programmed the Hubble to focus on a teeny-tiny patch of sky (about the size of the head of a pin, held at arm's length from the viewer) and gather as much light as possible from that single point.
The image that was returned was astonishing. Hubble discovered thousands of galaxies in this minuscule patch of sky, allowing us to refine our estimate of the number of galaxies in the universe.
Additionally, this photograph revealed Hubble's greater potential — as a time machine. In astronomy, the further something is from us, the older it is (because light from faraway places takes a very long time to travel to Earth). As a result, the Hubble Deep Field contains not only a snapshot of spacetime, but also the history of our universe. In this image, galaxies appear to us as they did billions of years ago.
"What Webb will do is expand that field," Casey of the University of Texas at Austin explains. "So the tiny specks of light in the Hubble Deep Field will brighten and become more detailed; we'll be able to see spiral arms and structure, and then we'll see more specks of light even further in the past. With Webb, we're seeing further back in time."
Astronomers like Casey will be able to see so far back with Webb that they may be able to observe the very first stars and galaxies. Hubble has detected light that originated approximately 400 million years after the Big Bang and travelled approximately 13.3 billion years to reach us.
"That is quite a distance!" However, Webb is capable of transporting us 250 million years after the Big Bang," explains Casey, who has been granted permission to work with the Webb Space Telescope. "It may not seem like a significant difference. What's a few hundred million years in the grand scheme of things between friends? Indeed, it is the difference between witnessing the first stars to ever shine and arriving a little late following the funeral."
Astronomers refer to this time period as the "cosmic dawn," because it was during this time period that the universe's first starlight shone. The Webb will provide humanity with its first glimpse of it.
Beyond that, there are barriers that even the Webb cannot see through. The universe was shrouded in a "dense, obscuring fog of primordial gas" prior to the birth of stars, as the National Science Foundation explains. There is no light reaching our telescopes during this period, dubbed the cosmic dark ages.
The Hubble Space Telescope, named after eminent astronomer Edwin Hubble, was launched on April 24, 1990, and marked a watershed moment in the history of astronomy. On Earth, astronomers seek out remote mountaintops and deserts to build large telescopes in order to observe a dark sky free of pollution and artificial light. However, their view is obstructed by the Earth's atmosphere's slight haze and luminescence. As NASA puts it, space is the "ultimate summit." There is no better vantage point from which to view space than from within it.
Hubble has meant so much to so many people over the course of its three-decade existence. For one thing, it has gifted us with incomparably beautiful images such as those of the Lagoon Nebula and the Pillars of Creation.
Additionally, it has taught us about the universe's age, how stars explode, and about black holes. It played a significant role in establishing a number of the boundaries that the Webb hopes to push. Most significantly, its observations have led scientists to believe that the universe is expanding at an accelerating rate, propelled by an unfathomable force known as "dark energy."
Infrared Telescope
The Webb’s other advantage is the infrared light it collects. Light comes in a wide variety of colors. Although the human eye can perceive only a narrow band of light called visible light, the universe contains an abundance of light outside this range, including higher-frequency, higher-energy forms such as ultraviolet and gamma rays. Then there's light with a lower energy and longer wavelengths: infrared, microwaves, and radio.
Hubble collects visible light, ultraviolet light, and a small amount of infrared light. The Webb is primarily an infrared telescope, which means that it detects light with a longer wavelength than our eyes can detect. This may appear nerdy and technical, but it is what enables Webb to peer further back in time than Hubble.
Due to a phenomenon called redshift, infrared light is frequently very old light. When a light source moves away from a viewer, it is stretched out, morphing into a longer and longer wavelength and becoming increasingly reddened. (The converse is also true: As a light source approaches, the wavelengths shorten, becoming bluer.) It's comparable to what occurs when a siren sounds: As the siren approaches, the pitch increases, then decreases as it fades away.
Due to the constant expansion of space, the universe's most distant objects are moving away from us. "And as light from those distant galaxies travels through space, it is literally stretched by the expansion of space," Straughn explains.
Consider a very distant star. Although the light from that star originates in the visible spectrum, it is stretched on its way to us. It becomes increasingly red. "So when we look at distant galaxies with Hubble, we see these tiny red nuggets," Straughn explains. Eventually, these extremely distant, ancient galaxies become red enough to fall into the infrared spectrum. Webb is able to perceive this ancient light that has become imperceptible to the naked eye.
Conveniently, infrared light has additional applications. It's an excellent type of light for studying exoplanets. For example, if you were on a planet orbiting another star and desired to see Earth, visible light would be insufficient.
"The Earth's peak is in the infrared," says astronomer Kevin Stevenson of the Johns Hopkins Applied Physics Laboratory, who plans to use the Webb in his research. Therefore, if we want to study a planet similar to Earth in another solar system, "what we really want to do is observe at infrared wavelengths, because that is where the Earth's light is emitted."
Scientists studying exoplanets, such as Stevenson, will use the Webb to analyze the atmospheres of these worlds: The Webb is capable of determining the chemical composition of some of the gases in their atmospheres. "We can detect water, carbon monoxide, carbon dioxide, and methane," Stevenson explains. While these are not conclusive signs of life on their own, they raise intriguing questions: What caused the methane and carbon dioxide to be produced? Could it have been a moment of life?
"Don't we all want to discover another Earth?" According to Stevenson. "The prospect of answering the question 'are we alone?' has occupied our minds for centuries. And I believe that with James Webb, we will have our first opportunity to truly address that question." This $10 billion gadget hopefully will not break
Challenging Tasks
Scientists were clearly eager to get started, but the Webb revolution has taken time due to the Webb's complexity. "Because it is so large, no rocket is large enough to launch it fully deployed," Straughn explains. That is why the telescope was required to be folded in order to fit inside a rocket. "Therefore, the entire process of constructing a deployable telescope in space is the source of a great deal of engineering difficulty."
The fact that, while Hubble was launched approximately 340 miles above the Earth, Webb will be nearly a million miles away — four times the distance between the Earth and the moon — raises the stakes.
This means that if Webb breaks, it will be rendered unusable by human hands. That is frightening, given the Hubble's history. Soon after the Hubble was launched in 1990, engineers discovered a problem with the telescope's mirror; the telescope's initial images were fuzzy, necessitating the launch of a space shuttle to repair it. With the Webb, this will not be possible. It must simply work.
It will be remote for a reason. Due to the fact that Webb is an infrared telescope, it must be kept cold. The Earth is naturally warm and glows in the infrared spectrum. "Anything that is warm emits infrared light," Straughn explains. "If the telescope were warm, it would glow and see its own image."
The Webb will revolve around a point known as a Lagrange point. This is a point in space where the telescope can maintain a constant temperature while also remaining aligned with the Earth as both orbit the sun.
Surprisingly, any scientist in the world can apply to use the Webb Space Telescope, provided they submit a peer-reviewed proposal. It's a fairly competitive field. In 2020, the Space Telescope Science Institute, based at John Hopkins University in Maryland, will solicit proposals for Webb's first observing run. Approximately a quarter of the proposals received acceptance.
"It feels as though a piece of me is still stunned," says Lisa Dang, a McGill University physics PhD student who was one of the fortunate few to use the Webb. “And the other part is having this imposter syndrome — like, these data better be really amazing.”
Dang will investigate one of the most extreme planets ever discovered: K2-141 b, a planet 202 light-years from Earth and so close to its host star that its surface is believed to be covered in a lava ocean. If there are clouds, they are almost certainly made of vaporized rock, which could precipitate out as "rock rain." Although little is known about this lava world, Dang intends to use the Webb to study its atmosphere and determine what is possible on this extreme world.
Winning the project proposal "for the first time made me feel like an astronomer," Dang says. "However, it also brings K2-141 b into sharp focus."
This is the capability of a telescope on a scale never seen before, such as the Webb. It will aid astronomers like Dang in filling in the cosmos's blank spaces.
"It's incredible, when you stop to consider it, that we can piece together the history of what occurred before the Earth or the sun even existed," Casey says.
The Inner Journey
Technological marvels have made the Webb Telescope possible, which will help us answer so many puzzles regarding the origin of the universe, nature of reality, dark matter and existence of life outside the earth. It is a miracle.
Equally miraculous is the inner space that we all possess. We do have today the capacity to explore the inner space, psychologically, neurologically and philosophically. Though this inner spaces are different from the technological outer space, there are as significant of more than the outer space that Webb Telescope is exploring.
Unless we earnestly try to understand the inner space, including love, truth, beauty and evil, we will be at a terrible disadvantage. Unless we know ourselves and understand the inner workings of ourselves to cope with our own anxieties and hopes, Einstein will prove right. “All of our exalted technological progress, civilization for that matter, is comparable to an axe in the hand of a pathological criminal.” That will have terrible consequences. Unless we also grow in inner wisdom and understanding along with our awareness of the outer world, we will be at a loss.
So, we are called to admire both the miracle of the world outside and inside. Just as we understand the outer world, we need to understand the inner world too. Religion, psychology, theology and philosophy will help us for the latter! So Immanuel Kant is right. “Two things fill the mind with ever new and increasing admiration and awe, the more often and steadily we reflect upon them: the starry heavens above me [outer space] and the moral law [inner space] within me.”
Click here to read other articles of the author