Out Of This World Discoveries Made By The James Webb Space Telescope

By John Oncea, Editor

As we continue to explore the data provided by JWST, the potential for discovery is limitless. Each new image and dataset brings us closer to unraveling the mysteries of the universe, inspiring curiosity and wonder.

The James Webb Space Telescope (JWST) is a tribute to human engineering, equipped with cutting-edge technology that provides deeper views into space than ever before. It has observed the formation of stars and galaxies, studied the atmospheres of exoplanets, and even looked back in time to the early universe.

JWST’s observations have been made possible by sophisticated instruments including the Near Infrared Camera (NIRCam), the Mid-Infrared Instrument (MIRI), and the Fine Guidance Sensor/Near InfraRed Imager and Slitless Spectrograph (FGS/NIRISS), and these instruments were made possible by an international team of engineers, scientists, and researchers.

This collaboration has allowed JWST to make groundbreaking discoveries – such as detecting the earliest galaxies formed after the Big Bang – that are not just a leap forward in our understanding of galaxy formation but also provide critical data on the conditions of the early universe.

By peering through cosmic dust and gas with infrared cameras, hidden structures of ancient galaxies have been revealed. In addition, the search for extraterrestrial life has been made more interesting because of JWT’s ability to analyze the atmospheres of exoplanets, study the chemical compositions of these distant worlds, and provide data to scientists to use to identify potential biosignatures that may indicate the presence of life.

While not all of JWST’s discoveries are as monumental as the discovery of life, they are all interesting in their own right. Here, we look at some of those discoveries but first, we look at some of the technologies that are allowing JWST to make them.

Some Of The Technologies On Board JWST

Part of the mission of JWST is to search for small, potentially habitable planets in the Goldilocks zone. Drs. Knicole Colón and Christopher Stark, two Webb project scientists at NASA’s Goddard Space Flight Center, write, “The potentially habitable worlds Webb is observing are all transiting exoplanets, meaning their orbits are nearly edge-on so that they pass in front of their host stars.

“Webb takes advantage of this orientation to perform transmission spectroscopy when the planet passes in front of its star. This orientation allows us to examine the starlight filtered through the atmospheres of planets to learn about their chemical compositions.”

Performing transmission spectroscopy of planets, as well as the other techniques used by JWST, is possible thanks to innovative and powerful technologies ranging from optics to detectors to thermal control systems. According to NASA, “Innovations include a primary mirror made of 18 separate segments that unfold and adjust to shape after launch. The mirrors are made of ultra-lightweight beryllium. Webb’s biggest feature is a tennis court-sized five-layer sunshield that attenuates heat from the Sun more than a million times.

“The telescope’s four instruments – cameras and spectrometers – have detectors that can record extremely faint signals. One instrument (NIRSpec) has programmable microshutters, which enable the observation of up to 100 objects simultaneously. Webb also has a cryocooler for cooling the mid-infrared detectors of another instrument (MIRI) to a very cold 7 K to operate properly.”

NASA breaks down several other JWST technological innovations as follows:

• Folding segmented mirror: Engineers built this mirror in segments on a structure that folds up, like the leaves of a drop-leaf table so that it can fit into a rocket.
•  Lightweight optics: NASA set out to research new ways to build mirrors for telescopes. The Advanced Mirror System Demonstrator (AMSD) program was a four-year partnership between NASA, the National Reconnaissance Office, and the U.S. Air Force to study ways to build lightweight mirrors.
• Cryogenic actuators & mirror control: Lee Feinberg, Webb Optical Telescope Element Manager at NASA Goddard explains, “Aligning the primary mirror segments as though they are a single large mirror means each mirror is aligned to 1/10,000th the thickness of a human hair. Even more amazing is that the engineers and scientists working on JWST’s telescope had to invent how to do this.”
• Wave Front Sensing: Wavefront sensing and control was developed to sense and correct any errors in the telescope’s optics. This is essential to making the 18 mirror segments work together as a single giant mirror.
• JWST's Sunshield: The Sunshield reduces the temperature between the hot and cold side of the spacecraft by almost 600 degrees Fahrenheit in the span of its 5 layer, 4.8m height – from approximately 185F on the hot side to approximately -388F on the cold side.
• Sunshield coatings: JWST deployed a tennis-court-sized Sunshield made of five thin layers of Kapton E with aluminum and doped-silicon coatings to reflect the sun’s heat into space.
• Improved Detectors: JWST has extended the state of the art for infrared detectors by producing arrays that are lower noise, larger format, and longer lasting than their predecessors.
• Microshutters: Microshutters are tiny windows with shutters that each measure 100 X 200 microns, or about the size of a bundle of only a few human hairs. The microshutter device can select many objects in one viewing for simultaneous high-resolution observation which means much more scientific investigation can get done in less time.
• Cryocooler: JWST’s MIRI instrument carries detectors that need to be at a temperature of less than 7 kelvin to operate properly. This temperature is not possible on JWST by passive means alone so it carries an innovative cryocooler that is dedicated to cooling MIRI’s detectors.
• Backplane: The backplane must carry more than 2400kg (2 1/2 tons) of hardware. It is required to be essentially motionless so the mirrors can see far into deep space. To meet this requirement, the backplane was engineered to be steady down to 32 nanometers, which is 1/10,000 the diameter of a human hair.
• Cryogenic Data Acquisition ASIC: A-to-D conversion is nothing new, but the technical challenge that JWST faced was doing it at the observatory’s super-cold cryogenic operating temperatures in an Application-Specific Integrated Circuit (ASIC).

JWST And Photonics

In addition to transmission spectroscopy mentioned earlier, several other photonic techniques are playing a crucial role in JWST’s groundbreaking discoveries starting with its advanced infrared detectors made from Mercury Cadmium Telluride (HgCdTe) and Arsenic-doped Silicon (Si) Detectors. These detectors convert incoming infrared light into electronic signals that can be processed to form images and spectra.

JWST also engages in cryogenic operation via detectors that operate at extremely low temperatures to minimize thermal noise, a concept deeply rooted in photonics. Photonics principles also guide the design of cryogenic cooling systems that keep the detectors at their operating temperatures.

JWST includes coronagraphs in its instruments to block out the light of bright stars so that faint objects, like exoplanets, can be observed. The telescope’s secondary mirror can be adjusted in real time to correct any distortions in the incoming light, a technique rooted in photonics. This adaptive optics system is crucial for maintaining image quality over long observation periods.

Photonics also plays a role in how data is transmitted from the JWST back to Earth. High-speed, high-efficiency optical communication technologies ensure that the vast amounts of data collected by the telescope are transmitted quickly and accurately.

The photonics-based technologies integrated into the JWST have allowed JWST to observe some of the most distant galaxies, providing insights into the early stages of the universe. Using its advanced spectroscopic capabilities, JWST has detected and analyzed the atmospheres of exoplanets, revealing their composition and potential habitability. In addition, the telescope has provided detailed images of star-forming regions and protoplanetary disks, enhancing our understanding of how stars and planets form.

What All Of This Has Helped JWST Discover

According to Webb Space Telescope, “Science discoveries made by the JWST are expected to revolutionize our understanding of the cosmos and our origins within the universe. JWST’s large mirror, near- to mid-infrared sensitivity, and high-resolution imaging and spectroscopic capabilities will reveal parts of the universe hidden from our eyes, such as stars among clouds of dust, water in the atmospheres of other worlds, and light from the first galaxies that ever formed.”

The list of discoveries made by JWST is impressive, including “an astonishing breakthrough” when an international team of astronomers used it to identify the most distant galaxy ever observed, dating back to just 290 million years after the Big Bang. This galaxy, named JADES-GS-z14-0, holds a redshift of 14.32, shattering previous records and offering profound insights into the early universe’s formation and evolution.

“These galaxies join a small but growing population of galaxies from the first half billion years of cosmic history where we can probe the stellar populations and the distinctive patterns of chemical elements within them,” explained Dr. Francesco D’Eugenio of the Kavli Institute for Cosmology at the University of Cambridge.

“Along with the two noted galaxies,” writes Hot Hardware, “the team added they found many hundreds of candidate galaxies from the first 650 million years after the Big Bang. During early 2023, the team discovered a galaxy in its data that had strong evidence of being above a redshift of 14. However, some properties still had the team a bit wary of the findings.”

“The source was surprisingly bright, which we wouldn’t expect for such a distant galaxy, and it was very close to another galaxy such that the two appeared to be part of one larger object,” remarked Stefano Carniani from Scuola Normale Superiore in Pisa, Italy. “When we observed the source again in October 2023 as part of the JADES Origins Field, new imaging data obtained with JWST’s narrower NIRCam (Near-Infrared Camera) filters pointed even more toward the high-redshift hypothesis. We knew we needed a spectrum, as whatever we would learn would be of immense scientific importance, either as a new milestone in JWST’s investigation of the early universe or as a confounding oddball of a middle-aged galaxy.”

In addition to finding distant galaxies, JWST has made several unusual and perplexing discoveries in the past year that have challenged our understanding of the early universe and galaxy formation. Here are some of the most notable ones, according to Live Science:

• Spotting Dozens of Rogue JuMBOs: The telescope discovered 42 pairs of Jupiter-mass binary objects (JuMBOs) – Jupiter-sized objects drifting through space in pairs, some as far apart as 390 times the Earth-Sun distance. These objects are too small to be stars but their existence in pairs makes them unlikely to be rogue planets ejected from solar systems, pointing to a new and unexplained formation mechanism.
• Potential Signs of Alien Life: Webb detected the potential biosignature gas dimethyl sulfide (DMS) in the atmosphere of the exoplanet K2-18b, a sub-Neptune planet orbiting in the habitable zone of a red dwarf star. DMS is a compound only known to be produced by microscopic algae on Earth, hinting at the tantalizing possibility of extraterrestrial life on this watery world.
• Six Impossible Massive Galaxies at Cosmic Dawn: The telescope discovered six enormous galaxies dating back to just 500-700 million years after the Big Bang, containing almost as many stars as the Milky Way. Their existence at such an early cosmic epoch defies our current models of galaxy formation and evolution, prompting scientists to suggest our understanding of the early universe may need revising.
• Unusually Bright Universe Breaker Galaxies: Related to the above, JWST found several unusually bright galaxies from the first billion years after the Big Bang that seem to be glowing far more intensely than expected for that era. Their extreme luminosity has left astronomers puzzled about what could be powering these brilliant infant galaxies.

Space.com adds complex organic molecules in a galaxy that existed over 12 billion years ago, similar to those found in smoke and smog which provide insights into the chemistry of the early universe to the list. They also note Wolf-Rayet star rings which, shaped by interactions with a companion star, offer a unique look at the life cycle of massive stars​.

Finally, JWST captured detailed images of Uranus, revealing its faint rings and atmospheric features with unprecedented clarity. According to Science News, this provides new insights into the planet’s atmospheric dynamics and seasonal changes​.