NASA Reveals James Webb Space Telescope's First Full-Colour Images, Opening a New Era in Astronomy

Baltimore, USA · 12 July 2022 — NASA, in partnership with the European Space Agency (ESA) and the Canadian Space Agency (CSA), released the first full-colour images and spectroscopic data from the James Webb Space Telescope (JWST), marking the official beginning of the observatory's general science operations. The release followed a preview the previous day, when President Joe Biden unveiled the first image — Webb's Deep Field view of the galaxy cluster SMACS 0723 — at a White House event.

The images demonstrated the telescope's capabilities across its core scientific themes: the early universe, the lifecycle of stars, galaxies over time, the atmospheres of exoplanets, and stellar death. Together, they represented the culmination of a decades-long international collaboration and a complex six-month commissioning process following the telescope's launch on 25 December 2021.

Webb's First Deep Field

The first publicly released image, SMACS 0723, is the deepest, sharpest infrared image of the distant universe to date. The image showcases the galaxy cluster as it appeared 4.6 billion years ago. The combined mass of the galaxy cluster acts as a gravitational lens, magnifying and distorting the light from more distant galaxies behind it, revealing galaxies that existed when the universe was less than a billion years old.

The telescope's Near-Infrared Camera (NIRCam) brought distant galaxies into sharp focus, exposing features that had never been seen before. The image demonstrated Webb's ability to peer through cosmic dust that obscures visible-light observations.

The Carina Nebula: Cosmic Cliffs

Webb's image of the Carina Nebula, designated NGC 3324, revealed what scientists dubbed the "Cosmic Cliffs" — the edge of a giant gaseous cavity within a star-forming region. The image unveiled stellar nurseries and individual stars that had been previously hidden by cosmic dust.

The cavernous region, carved by intense ultraviolet radiation and stellar winds from massive young stars, provides a window into the earliest stages of star formation. The image revealed hundreds of previously obscured stars and numerous jets and outflows from young stars.

Stephan's Quintet

The image of Stephan's Quintet, a visual grouping of five galaxies, provided a detailed look at galactic interactions and mergers. The composite image contained over 150 million pixels and was constructed from nearly 1,000 separate image files.

The observation revealed never-before-seen details of the galaxy group, including bright clusters of millions of young stars and regions of intense star formation triggered by the gravitational interactions between the galaxies. The data also showed outflows driven by a black hole in one of the galaxies, demonstrating Webb's ability to trace the energetic processes that shape galactic evolution.

The Southern Ring Nebula

Webb's observations of the Southern Ring Nebula (NGC 3132) illustrated the final stages of a star's life. The images showed the gas and dust ejected as a dying star shed its outer layers, creating a planetary nebula. The telescope's infrared vision penetrated the dust to reveal a second star orbiting the dying one — a binary system that had been difficult to observe with previous instruments.

Exoplanet Atmosphere: WASP-96 b

Webb's first exoplanet observation was not an image but a transmission spectrum of the hot gas giant WASP-96 b, located roughly 1,150 light-years away. As the planet transited its host star, Webb's Near-Infrared Imager and Slitless Spectrograph (NIRISS) captured the starlight filtered through the planet's atmosphere.

A New Era of Infrared Astronomy

The James Webb Space Telescope is the largest and most powerful space telescope ever built. Its 6.5-metre primary mirror, composed of 18 hexagonal beryllium segments, collects infrared light from the most distant objects in the universe. The telescope operates at the second Lagrange point (L2), approximately 1.5 million kilometres from Earth, where its sunshield maintains its instruments at cryogenic temperatures.

Unlike its predecessor, the Hubble Space Telescope, which primarily observes in visible and ultraviolet light, Webb is optimised for infrared observations. This allows it to see through dust clouds, observe the redshifted light from the earliest galaxies, and study the formation of stars and planetary systems in unprecedented detail.

Sources

• NASA, Webb's First Images Are Here, 12 July 2022 — nasa.gov
• ESA/Webb, Webb's first images — esawebb.org
• NASA James Webb Space Telescope mission page — nasa.gov
• Wikipedia: James Webb Space Telescope first images — wikipedia.org