Exploring the James Webb Space Telescope
Discover the remarkable James Webb Space Telescope, a game changer for space exploration, unveiling the mysteries of the universe.
Webb was launched on an ArianeSpace Ariane5 rocket on December 25, 2021. Credit: NASA/Chris Gunn
On Christmas Day in 2021, the James Webb Space Telescope (JWST) was launched on an Ariane 5 Rocket from Europe's Spaceport in French Guiana.
Ten days later, on January 4, 2022 the James Webb Space Telescope (JWST) successfully deployed its primary mirror and sunshield. This milestone marked a significant step in the mission, allowing the telescope to begin its complex alignment and calibration processes. It deployed perfectly, marking an incredible achievement for all of us in our quest to better understand the universe and the Laws of Physics.
Then, on January 24, 2022 the JWST, nearly a million miles away from Earth, slips into orbit around a point in space known as the second Lagrange Point, or L2, one of five spots where the pull of Sun and Earth interact to form stable or nearly stable gravitational zones. This orbit enables the JWST to capture light from the first stars and galaxies that formed in the aftermath of the Big Bang.
Some 20,000 people worked on the James West Space Telescope for 25 years. What they accomplished is one of humankind's greatest achievements!
NGC 1365 captured by the James Webb Space Telescope/Credit: ESA
The Need for a New Telescope
To begin, let's explore why scientists built a new telescope, and the extensive effort put into its creation. Hubble's discoveries impacted astronomy, leading to additional research and textbook revisions. Over 30 years, Hubble has sparked our curiosity and imagination, which drives us to seek further knowledge by expanding our vision.
The James Webb Space Telescope is the largest, most technically advanced telescope ever built. Its size and infrared capabilities surpass Hubble's, enabling observations back over 13.5 billion years to witness the birth of stars and galaxies. Comparing early galaxies to modern ones helps us understand galactic evolution over billions of years.
Planning and Design
The James Webb Space Telescope (JWST) is a result of global teamwork in space exploration. It started in 1996 and has taken over 20 years to plan, design, build, and test. NASA, the European Space Agency (ESA), and the Canadian Space Agency (CSA) collaborated to create this incredible telescope. With a cost exceeding 10 billion dollars and 25 years of development, the JWST symbolizes NASA's commitment to advancing scientific knowledge. By investing so much time and money in the project, NASA shows how important the JWST is for expanding our understanding of the universe.
Fifty years ago, engineers heavily relied on physical 'engineering models' or 'breadboards' to test and ensure the robustness of space system development. However, for systems like JWST, newer methods are required due to size and cost constraints.
Design is increasingly reliant on analysis tools, with JWST requiring even more analysis. The design process for JWST included traditional disciplines but focused on coordinating unique trade studies due to its unprecedented architecture. Mass constraints mean trade studies are interconnected at the systems level. Integrated Systems Analyses (IM) and Modeling played key roles in predicting on-orbit performance and verification, managed by the Project Mission Systems Engineering (MSE) Organization.
Well over 70 observatory-level trade studies were conducted prior to the JWST Critical Design Review in April 2010. These trades involve the selection of the orbit parameters, launcher adapters, angular momentum management, command and telemetry formats and data rates, observatory thermal design, propulsion subsystem design, and test facility design.
Capabilities and Technology
Observing in the infrared spectrum
The James Webb Space Telescope has incredible capabilities, including its ability to capture detailed images in the infrared spectrum. Webb cuts through the dust and gas with its infrared vision to observe stars and planetary systems forming. It features a cryogenic 6.6 m aperture and is deployable as an infrared observatory.
The Optical Telescope Element (OTE) with a payload of four science instruments is assembled into an Integrated Science Instrument Module (ISIM) that provide imagery and spectroscopy in the near-infrared band (between 0.6 and 5 μm) and in the mid-infrared band (between 5 and 28.1 μm).
Advanced instruments and sensors
Webb’s unprecedented scientific power results from both the size of its primary mirror and the extreme sensitivity and precision of its four scientific instruments:
Mid-Infrared Instrument (MIRI)
Near-Infrared Camera (NIRCam)
Near-Infrared Spectrograph (NIRSpec)
Near-Infrared Imager and Slitless Spectrograph/Fine Guidance Sensor (NIRISS/FGS)
Each of Webb’s four instruments studies a wide range of objects and phenomena in space, such as planets, stars, galaxies, gas clouds, debris disks, black holes, and dark matter.
What makes each instrument unique is its specific combination of components, observing modes, wavelength range, field of view, and resolution.
While some investigations are conducted with a single instrument, and observing mode, most rely on a combination of instruments and/or observing modes.
Mid-Infrared Instrument (MIRI)
Components: Camera, Coronagraphs, Spectrographs, Integral Field Unit
Wavelength range: 4.9 µm – 27.9 µm (mid-infrared, which is unique to MIRI)
Detectors: Arsenic-doped silicon
Imaging modes: Standard Imaging, Coronographic Imaging, Time-Series Imaging
Spectroscopy modes: Single-Object Slitless Spectroscopy, Slit Spectroscopy, Integral Field Unit Spectroscopy, Time-Series Spectroscopy
Resolution: Medium-resolution imaging; Low- and medium-resolution spectroscopy
MIRI provides imaging and spectroscopy capabilities in the mid-infrared. As the only mid-infrared instrument, astronomers rely on MIRI to study cooler objects like debris disks, which emit most of their light in the mid-infrared, and extremely distant galaxies, whose light has been shifted into the mid-infrared over time.
MIRI was developed through a collaboration between the European Consortium (EC) and the Jet Propulsion Laboratory (JPL).
Near-Infrared Camera (NIRCam)
Components: Camera, Coronagraphs, Spectrographs
Wavelength range: 0.6 µm – 5 µm (red to near-infrared)
Detectors: Mercury cadmium telluride
Imaging modes Standard Imaging, Coronagraphic Imaging, Time-Series Imaging
Spectroscopy modes: Wide-Field Slitless Spectroscopy, Time-Series Spectroscopy
Resolution: High-resolution imaging and spectroscopy
NIRCam is Webb’s primary near-infrared imager, providing high-resolution imaging and spectroscopy for a wide variety of investigations. Because NIRCam is the only near-infrared instrument with coronagraphic and time-series imaging capabilities, it plays a crucial role in many exoplanet studies.
In addition to imaging and spectroscopy, NIRCam also plays a part in Webb’s wavefront sensing and control system, which detects and corrects for slight irregularities in the shape of the primary mirror or misalignment between mirror segments, giving the telescope the ability to focus clearly on objects near and far.
NIRCam was built by a team at the University of Arizona and Lockheed Martin’s Advanced Technology Center.
Near-Infrared Spectrograph (NIRSpec)
Components: Spectrographs, Integral Field Unit, Microshutter Array (Unique to NIRSpec)
Wavelength range: 0.6 µm – 5.3 µm (red to near-infrared)
Detectors: Mercury cadmium telluride
Imaging modes: N/A (with the exception of images collected during Integral Field Unit Spectroscopy)
Spectroscopy modes: Slit Spectroscopy, Multi-Object Spectroscopy (Unique to NIRSpec), Integral Field Unit Spectroscopy, Time-Series Spectroscopy
Resolution: Low-, Medium-, and High-resolution spectroscopy
NIRSpec is one of Webb’s versatile tools for near-infrared spectroscopy. It offers single-slit spectroscopy for specific object spectra, an integral field unit for spatial variations, and a microshutter array capturing dozens of object spectra simultaneously. This efficient design contributes to Webb's suitability for studying distant, faint galaxies.
NIRSpec was built for the European Space Agency by Airbus Industries with the microshutter array (MSA) and detector sub-systems fabricated by NASA.
Near-Infrared Imager and Slitless Spectrograph (NIRISS)/Fine Guidance Sensor (FGS)
Components: Camera, Spectrographs, Aperture Mask
Wavelength range: 0.6 µm – 5 µm (red to near-infrared)
Detectors: Mercury cadmium telluride
Imaging modes: Standard Imaging, Aperture Mask Interferometry (Unique to NIRISS)
Spectroscopy modes: Wide-Field Slitless Spectroscopy, Single-Slit Spectroscopy
Resolution: High-resolution imaging; Low- and Medium-resolution spectroscopy
NIRISS offers near-infrared imaging and spectroscopic capabilities. It is the only instrument capable of aperture mask interferometry, enabling it to capture high-resolution images of bright objects, compared to the other imagers.
Housed in the same assembly as NIRISS is Webb’s Fine Guidance Sensor (FGS). The FGS is a camera system designed to ensure Webb remains stable and points in the right direction during observations. The FGS detects and identifies guide stars and ensures that Webb is locked onto those stars for the entire observation.
NIRISS is a contribution of the Canadian Space Agency. Honeywell International designed and built the instrument in collaboration with a team at the Université de Montréal. Additional technical support was provided by the National Research Council of Canada’s Herzberg Astronomy and Astrophysics Research Centre.
The bright star at the center of NGC 3132, Southern Nebula Ring. NASA, ESA, CSA, STScI
Scientific Goals
Exploring the formation of galaxies
The James Webb Space Telescope represents the pinnacle of space exploration technology, and offers unprecedented insight into the formation and evolution of galaxies. JWST detects faint signals from distant galaxies, capturing elusive cosmic moments.
JWST surpasses its predecessors by utilizing infrared observation, uncovering hidden galaxy formation secrets. With a focus on the early universe, JWST serves as a time machine for astronomers to witness the evolution of galaxies over billions of years.
Through meticulous analysis, JWST delves into gravitational forces, gas dynamics, and stellar feedback that shape galaxy formation. By studying the faint glow of primordial galaxies, JWST sheds light on the cosmos' origins and answers fundamental questions about the structure of the cosmic web.
Revolutionizing Exoplanet Research
The James Webb Space Telescope's ability to study exoplanets and their atmospheres offers a unique opportunity to explore the potential habitability of these distant worlds. Exoplanets orbit stars outside of our solar system. By analyzing atmospheric compositions, scientists may identify conditions conducive to life, pushing the boundaries of astrobiology. JWST possesses the versatility to capture a comprehensive spectrum of exoplanetary signatures, from the subtle nuances of atmospheric gases to the intricate interplay of thermal emissions.
By utilizing infrared observation, JWST surpasses previous telescopes' limitations, allowing it to uncover the mysteries of distant worlds. Focused on exoplanetary transits and occultations, JWST presents new opportunities to analyze alien atmospheres, detecting molecules like water, methane, and carbon dioxide.
Additionally, JWST goes beyond mere detection by offering detailed insights into the dynamic nature of exoplanetary atmospheres. This revolutionary capability allows astronomers to study atmospheric dynamics, climate variations, and potential signs of geological or biological activity, leading to a better comprehension of planetary evolution.
In essence, the James Webb Space Telescope stands as a beacon of innovation in the field of exoplanet research, poised to revolutionize our understanding of planetary systems beyond our solar system. JWST, with its transformative capabilities and insatiable curiosity, beckons us to embark on a journey of exploration, where each observation unveils a new chapter in the ongoing saga of cosmic discovery.
The Search for Dark Matter
The James Webb Space Telescope's advanced instruments and sensitivity make it valuable for studying dark matter, a mysterious component of the universe. By analyzing cosmic structures and phenomena, the telescope could provide insights into the distribution and properties of dark matter.
This addition connects with the content by showcasing how the telescope's capabilities extend to investigating fundamental aspects of the universe, such as dark matter, contributing to broader scientific knowledge. By exploring the formation of galaxies and studying exoplanets, the telescope will provide valuable insights into the presence and role of dark matter.
Launch and Deployment
On July 17, 2022 Ari Shapiro with NPR wrote:
"This week, we got a new view of space. And it was epic."
"Cosmic cliffs of glowing gas, spinning galaxies, dying stars. The James Webb telescope caught those images of ancient history — billions of light years away — showing what the universe looked like when it was just forming after the Big Bang."
"Some 20,000 people worked on the project for almost two decades, including engineer Bill Ochs, who has been the project manager since 2011. Bill Ochs joined All Things Considered to share the journey to this monumental snapshot in time."
This interview has been lightly edited for length and clarity.
Interview Highlights:
On what the project first looked like when he joined
"When I came on board, they had just gone through an external review and it was basically concluded that they weren't going to make their current launch date, which I think at that time was 2013. We didn't have enough money.”
"So when I came on board, I was asked to go ahead and put together a re-plan, which was quite challenging because, you know, you're brand new onto something. To re-plan a mission of this complexity is a pretty steep learning curve. The complexity of this mission and testing it on the ground made us understand we really needed a little bit more time.”
"In all honesty, I don't think I ever got to that point of really feeling like, hey, it's never going to work. I did hit my retirement age at one point [three years ago], and I thought, you know, maybe I should just retire. And then I'm like, no, I got to see this out to the end."
"But that was it. I mean, I tell folks all the time. The type of words I never heard on this project in the 11 1/2 years that I have been here is "give up", "failure" — never heard those words. It was always, "Hey, we got an issue." Whether it was a design complexity issue or, in this case, we did have some mistakes that were made: How do we correct this? How do we make sure this doesn't happen again? And how do we move on?"
On the moment it all came together
"Well, it actually came in steps. So I really wasn't worried about the launch. The launch vehicle team was outstanding. But those first 2 1/2 weeks of deployment, that's probably the highest anxiety level that we had. I'm a pretty laid-back person. I've done operations before, so I'm pretty calm throughout the whole thing. But definitely, the anxiety level was up.”
"Prior to launch, folks talk, we had 344 single-point failures. A single-point failure means if this one thing fails, we could potentially lose the whole mission. And a majority of those single-point failures were going to be retired through that first two weeks or so of deployments. So when you think about it, anything in that first two weeks could have maybe taken us out."
"When we got through the first two weeks, there was a big sigh of relief when we deployed that final mirror wing. Now you go through a period of checking out the rest of the spacecraft itself, and now we get ready to start aligning the mirrors. But there were 155 motors on the backs of these mirrors to make them function properly for us to do the alignments. Every single one of them worked. Every single one of them survived!”
Photo by NASA via Getty Images Handout / Getty Images
Recent Discoveries
Cheers! NASA’s Webb Finds Ethanol, Other Icy Ingredients for Worlds - March 14, 2024
What do margaritas, vinegar, and ant stings have in common? It's their chemical ingredients that NASA’s James Webb Space Telescope has identified surrounding two young protostars, known as IRAS 2A and IRAS 23385. Although planets are not yet forming around those stars, the molecules detected by Webb represent key ingredients for making potentially habitable worlds.
An international team of astronomers used Webb’s MIRI (Mid-Infrared Instrument) to identify a variety of icy compounds made up of complex organic molecules, like ethanol (alcohol), and likely acetic acid (an ingredient in vinegar). This work builds on previous Webb detections of diverse ices in a cold, dark molecular cloud.
“This finding contributes to one of the long-standing questions in astrochemistry,” said team leader Will Rocha of Leiden University in the Netherlands. “What is the origin of complex organic molecules, or COMs, in space? Are they made in the gas phase or in ices? The detection of COMs in ices suggests that solid-phase chemical reactions on the surfaces of cold dust grains can build complex kinds of molecules.”
As several COMs, including those detected in the solid phase in this research, were previously detected in the warm gas phase, they are believed to originate from the sublimation of ices. Sublimation is to change directly from a solid to a gas without becoming a liquid. Therefore, detecting COMs in ices makes astronomers hopeful about improved understanding of the origins of other, even larger molecules in space.
Discovery Alert: A ‘Super-Earth’ in the Habitable Zone - January 31, 2024
A “super-Earth” ripe for further investigation orbits a small, reddish star that, by astronomical standards, is fairly close to us – only 137 light-years away. The same system might also harbor a second, Earth-sized planet.
The bigger planet, dubbed TOI-715 b, is about one and a half times as wide as Earth, and orbits within the “conservative” habitable zone around its parent star. That’s the distance from the star that can give the planet the right temperature for liquid water to form on its surface. Several other factors would have to line up, of course, for surface water to be present, especially having a suitable atmosphere.
However, the conservative habitable zone, which is a narrower and potentially more robust definition than the broader “optimistic” habitable zone, places it in a prime position, at least based on the rough measurements made so far. The smaller planet could be only slightly larger than Earth, and might also dwell just inside the conservative habitable zone.
NASA’s Webb Depicts Staggering Structure in 19 Nearby Spiral Galaxies - January 29, 2024
It’s oh-so-easy to be absolutely mesmerized by these spiral galaxies. Follow their clearly defined arms, which are brimming with stars, to their centers, where there may be old star clusters, and – sometimes – active supermassive black-holes. Only NASA’s James Webb Space Telescope can deliver highly detailed scenes of nearby galaxies in a combination of near-, mid-near-, and mid-infrared light to clarify their structures. NASA publicly released a set of these images today.
Credit: NASA, ESA, CSA, STScI, Janice Lee (STScI), Thomas Williams (Oxford), PHANGS Team, Elizabeth Wheatley (STScI)
These Webb images are part of a large, long-standing project, the Physics at High Angular resolution in Nearby GalaxieS (PHANGS) program, which is supported by more than 150 astronomers worldwide. Before Webb took these images, PHANGS is already brimming with data from NASA’s Hubble Space Telescope, the European Southern Observatory’s Very Large Telescope’s Multi-Unit Spectroscopic Explorer, and the Atacama Large Millimeter/submillimeter Array, including observations in ultraviolet, visible, and radio light. Webb’s near- and mid-infrared contributions have provided several new puzzle pieces.
“Webb’s new images are extraordinary,” said Janice Lee, a project scientist for strategic initiatives at the Space Telescope Science Institute in Baltimore. “They’re mind-blowing even for researchers who have studied these same galaxies for decades. Bubbles and filaments are resolved down to the smallest scales ever observed, and tell a story about the star formation cycle.”
The team rapidly felt excitement as the Webb images flooded in. “I feel like our team lives in a constant state of being overwhelmed – in a positive way – by the amount of detail in these images,” added Thomas Williams, a postdoctoral researcher at the University of Oxford in the United Kingdom.
Webb’s NIRCam (Near-Infrared Camera) captured millions of stars in these images, which sparkle in blue tones. Some stars are spread throughout the spiral arms, but others are clumping tightly together in star clusters.
The telescope’s MIRI (Mid-Infrared Instrument) data highlights glowing dust, showing us where it exists around and between stars. It also spotlights stars that have not yet fully formed – they are still encased in the gas and dust that feed their growth, like bright red seeds at the tips of dusty peaks. “These are where we can find the newest, most massive stars in the galaxies,” said Erik Rosolowsky, a professor of physics at the University of Alberta in Edmonton, Canada.
Something else that amazed astronomers? Webb’s images show large, spherical shells in the gas and dust. “These holes may have been created by one or more stars that exploded, carving out giant holes in the interstellar material” explained Adam Leroy, a professor of astronomy at the Ohio State University in Columbus.
Now, trace the spiral arms to find extended regions of gas that appear red and orange. “These structures tend to follow the same pattern in certain parts of the galaxies,” Rosolowsky added. “We think of these like waves, and their spacing tells us a lot about how a galaxy distributes its gas and dust.” Study of these structures will provide key insights about how galaxies build, maintain, and shut off star formation.
Conclusion
The James Webb Space Telescope marks a groundbreaking advancement in our exploration of the universe. Launched amidst holiday celebrations on Christmas Day 2021, astronomers have already achieved significant milestones with this incredible telescope, including recent discoveries that have astronomers excited to revolutionize our understanding of the universe's structure and evolution.
With over two decades of planning, design, and testing involving a massive collaboration between NASA, the European Space Agency, and the Canadian Space Agency, the JWST represents one of humankind's most remarkable achievements, with the efforts of over 20,000 individuals culminating in its successful launch.
The JWST's unique capabilities and technology, from its superior resolution and sensitivity to its advanced instruments such as Mid-Infrared Instrument (MIRI) and Near-Infrared Camera (NIRCam), promise to reveal new information about galaxies, exoplanets, and the origins of life. With its infrared vision and state-of-the-art scientific instruments, the James Webb Space Telescope is paving the way for unprecedented discoveries in the realms of astronomy and astrophysics.
© 2024 by Vaughn Garner, All rights reserved.