# The James Webb Space Telescope: What It Has Taught Us About the Universe > Since it began observing in 2022, the James Webb Space Telescope has reshaped our view of the early universe, distant galaxies and the atmospheres of other worlds. Here is a clear guide to how it works and what it has found. *Section: Science — By Dr. Nadia Okoro (Science & Health Writer) — Published May 18, 2026 — 3 min read* Canonical URL: https://dailyjunction.co.uk/science/james-webb-space-telescope-discoveries Tags: James Webb Space Telescope, astronomy, NASA, space, exoplanets ## Key takeaways - The James Webb Space Telescope (JWST) is the most powerful space telescope ever built, launched in December 2021. - It observes mainly in infrared light, letting it see through dust and look back toward the earliest galaxies. - It orbits a point called L2, about 1.5 million kilometres from Earth, kept cold by a tennis-court-sized sunshield. - Key results include surprisingly mature early galaxies and detailed studies of exoplanet atmospheres. When the James Webb Space Telescope released its first full-colour images in July 2022, they were more than pretty pictures. They were a signal that astronomy had a new instrument capable of seeing the universe in ways nothing before it could. In the years since, Webb has steadily rewritten parts of the textbook. ## What JWST is The **James Webb Space Telescope (JWST)** is the largest and most capable space observatory ever launched. It was built by NASA in partnership with the European Space Agency (ESA) and the Canadian Space Agency (CSA), and launched on 25 December 2021. Its headline feature is a **6.5-metre primary mirror** made of 18 gold-coated hexagonal segments — far larger than Hubble's 2.4-metre mirror. A bigger mirror gathers more light, and more light means fainter, more distant objects come into view. ## How it works Two design choices define what Webb can do. **It sees in infrared.** Unlike Hubble, which works mostly in visible and ultraviolet light, Webb is optimised for infrared. This matters for two reasons: - The light from the earliest galaxies has been stretched to longer, redder wavelengths by the expansion of the universe. To see the first galaxies, you must look in the infrared. - Infrared light passes through clouds of cosmic dust that block visible light, letting Webb peer inside the nurseries where stars and planets are born. **It stays extremely cold.** Infrared is essentially heat, so the telescope must be colder than the things it observes. Webb orbits near a location called the **second Lagrange point (L2)**, about 1.5 million kilometres from Earth, and unfurls a five-layer sunshield the size of a tennis court. The shield keeps the Sun, Earth and Moon on one side, so the instruments on the other stay at around minus 230 degrees Celsius. > Webb is, in effect, a giant cold camera parked in the dark, designed to catch the faintest heat-glow of the distant cosmos. ## What it has taught us ### The early universe is surprisingly busy One of Webb's most discussed findings is that galaxies in the very early universe appear **more numerous, brighter and more mature** than many models predicted. Astronomers have identified candidate galaxies whose light set out only a few hundred million years after the Big Bang. The existence of such well-developed galaxies so early is prompting a healthy rethink of how quickly structure formed. ### A new era for exoplanet atmospheres Webb can analyse starlight that filters through the atmosphere of a planet as it passes in front of its star. By splitting that light into a spectrum, scientists can detect the chemical fingerprints of gases. Webb has detected molecules including carbon dioxide and water vapour in the atmospheres of planets beyond our solar system, opening a serious observational path toward studying potentially habitable worlds. ### Sharper views of star and planet birth By looking through dust, Webb has produced extraordinarily detailed images of star-forming regions, capturing jets from newborn stars and the discs of material from which planets assemble. These observations help connect theory to what actually happens as solar systems take shape. ### Familiar objects, new detail Closer to home, Webb has imaged planets, moons and rings in our own solar system with striking clarity, revealing features that ground-based telescopes struggle to resolve. ## Why it matters Every major leap in telescope capability has expanded what humanity can ask about its origins. Webb pushes the boundary of how far back in time we can look — toward the moment the first stars and galaxies switched on — while also turning its gaze on the question of whether other worlds might host the ingredients for life. The telescope is designed to operate for many years, and its discoveries are still accelerating. The picture it is painting is one of a universe that assembled itself faster, and in richer detail, than we expected. ## The bottom line The James Webb Space Telescope is a cold, gold-mirrored infrared observatory parked far from Earth, and it has already deepened our understanding of the early universe and the atmospheres of distant planets. It is less a single discovery than a new pair of eyes — and we are only beginning to use them. ## Frequently asked questions ### What is the James Webb Space Telescope? JWST is a large infrared space observatory developed by NASA with the European and Canadian space agencies. Launched in December 2021, it is the most powerful space telescope ever built and is designed to study the early universe, galaxy formation, stars, and the atmospheres of planets around other stars. ### How is JWST different from the Hubble Space Telescope? Hubble observes mainly in visible and ultraviolet light from low Earth orbit. JWST has a much larger mirror and observes primarily in infrared from a distant orbit, which lets it see fainter, more distant and dustier objects that Hubble cannot. ### Why does JWST observe in infrared? Light from the most distant galaxies is stretched into the infrared by the expansion of the universe, and infrared also passes through the dust clouds where stars and planets form. Observing in infrared is what lets Webb look both farther back in time and deeper into stellar nurseries. ### Where is the telescope located? JWST orbits the Sun near the second Lagrange point, or L2, roughly 1.5 million kilometres from Earth on the side away from the Sun. This keeps the Sun, Earth and Moon behind its sunshield so its instruments stay extremely cold. ## Sources - [NASA: James Webb Space Telescope](https://science.nasa.gov/mission/webb/) - [European Space Agency: Webb](https://www.esa.int/Science_Exploration/Space_Science/Webb) - [Space Telescope Science Institute](https://www.stsci.edu/) --- Daily Junction — https://dailyjunction.co.uk/science/james-webb-space-telescope-discoveries