All image credits: NASA, ESA, CSA, STScI
On Christmas Day in 2021, astronomers around the world watched with bated breath as the James Webb Space Telescope (JWST) soared into the sky aboard an Ariane 5 heavy-lift rocket from French Guiana in South America. The $10 billion observatory, which originally started life as the Next Generation Space Telescope in 1996, had faced numerous delays and bloated budgets, but throughout its long development, its promise never faded. It was designed to set a new standard for infrared astronomy; to become a kind of spiritual successor to the venerable Hubble Space Telescope; to illuminate a wide range of the biggest mysteries in space science.
The launch was more than successful – it overdelivered. Webb was sent towards its station with incredible efficiency, meaning its mission will last longer than intended, delivering even more breakthrough science. But after the initial excitement of the launch, there was yet another period of anticipation. It would take more than six months for the first full-colour images from the telescope to be revealed to the world on 12 July 2022. Its main imaging cameras, NIRCam (Near-Infrared Camera) and MIRI (Mid-Infrared Instrument) returned views of the cosmos that captured the imaginations of astronomers and the general public alike.
As we approach the first anniversary of the age of the JWST, we can already appreciate that it has exceeded all expectations, and the future is looking very bright. Here are eight incredible images from the first operational year of Webb.
The Pillars of Creation (MIRI)
These giant, gaseous talons in the Eagle Nebula are astronomical icons, made famous by Hubble in 1995. 27 years later, they are seen in a new light by MIRI, which isolates the delicate, dusty details. In contrast, the image contains relatively few stars, as they are generally not bright in the infrared. The result shows unprecedented depth and texture, which helps astronomers accurately model the size, shape and density of the nebula. Spectrographic data from the same instrument also reveal its chemical complexity. Webb is helping us gain a better understanding of how stars form from these awesome structures.
Fomalhaut’s mysterious debris disks (MIRI)
For decades, astronomers have speculated about whether the star Fomalhaut (Alpha Piscis Austrini) has its own planetary companion or not. Observatories such as the Hubble Space Telescope and Atacama Large Millimeter Array (ALMA) have carefully studied a ring of dusty debris known to encircle the young star, investigating a mysterious bright spot that looks suspiciously like a planet. The JWST, however, revealed much more detail with its Mid-Infrared Instrument, casting doubt on the likelihood of an exoplanet. The images suggest that the spot is a rather a large, comparatively dense cloud of material travelling within the ring. Webb also revealed inner belts closer to Fomalhaut, which had not been detected before.
The Cartwheel Galaxy (NIRCam and MIRI)
Data from both MIRI and NIRCam were combined to produce this composite image of the well-known Cartwheel Galaxy and its companions. Roughly 400 million years ago, this striking galaxy was formed in a high-speed collision, which resulted in two distinct rings that spread out like shockwaves. The spiral structure of the larger galaxy is still visible, forming the spokes of the wheel between the rings. The NIRCam data, coloured blue, includes many bright spots that are star clusters or individual, massive stars. The MIRI data, coloured red, reveals the dust that permeates the galaxy’s appealing structure.
Gargantuan Galactic Gravitational Lensing (NIRCam)
This mind-blowing deep field was one of Webb’s first light images, released to the public on 12 July 2022. It contains thousands of individual galaxies, a number of which are visibly distorted by the presence of otherwise unseen dark matter. At the centre of the scene is SMACS 0723, a massive cluster of galaxies 4.6 billion light-years distant. Dark matter within the cluster acts as a colossal lens – a gravitational lens – that bends light and smears the images of background galaxies. Webb’s sharp eye reveals fine details in these warped impressions like never before.
The Tarantula Nebula (NIRCam)
Spanning 340 light-years, this enormous, nebulous web surrounds the core of a monstrously large star-forming region, which is home to some tens of thousands of infant stars. JWST saw many of these stars for the first time, peering through the gas and dust that enshrouds them with its powerful infrared optics. Strong stellar winds from the massive star cluster present in the image are carving out a distinctive, bubble-like cavity in the nebula. The brighter-looking gas is hotter, whereas the rusty, darker gas farther from the cluster is cooler.
Strange spirals in NGC 1433 (MIRI)
The nearby barred spiral galaxy NGC 1433 is a remarkable sight for MIRI. Ordinarily less exciting in optical telescopes, it appears here as a speckled spiral within a speckled spiral; the bright eye of some unfathomable cosmic creature. Striking pink spots shine where clumps of gas emit infrared light, after absorbing the more powerful radiation from embedded or nearby young stars. We see star-forming activity in two rings. The incredible resolution of Webb makes clear the inner core of the galaxy along with its outer spiral arms. The two rings are really connected, with the outer ring making up the sweeping reaches of two large spiral arms at the tips of the central bar.
Neptune… and Triton! (NIRCam)
The JWST doesn’t just peer into the Galaxy and beyond – it’s also perfectly capable of breaking new ground in our own planetary neighbourhood. NIRCam’s view of Neptune is a perfect example. The remote planet positively glows in the infrared, as do its ordinarily ultra-faint rings. Weather patterns are visible in its atmosphere, and to the upper left, it’s large moon Triton makes an eight-pointed star through the uncommon Korsch optical system of the telescope. Infrared observations like these, which are impossible through the Earth’s atmosphere, are crucial to our ongoing investigation of the remote ice giants.
Cosmic Cliffs of the Carina Nebula (NIRCam)
Perhaps the most famous Webb image to date, and for good reason, this magnificent 123 megapixel mosaic does real justice to the grandiose Carina Nebula – a sublime portrait of one of the most complex and compelling regions of the Milky Way. The cosmic cliffs lie on the edge of a vast cavity within the nebula NGC 3324, which is about 7600 light-years from Earth. The radiation from young, very hot stars inside the cavity (out of frame above the top of the image) carves and erodes the apparent cliff face, which is evidently streaming away towards the bottom of the image. It’s easy to see why this image, one of the first to be released by the Webb team, adorned the backgrounds of millions of computers, tablets and phones.
Tom Kerss is an astronomer, astrophotographer, writer and speaker, specialising in the rewarding task of connecting people to their shared universe. He is the author of Observing Our Solar System, Northern Lights, Moongazing and Stargazing, all of which are available now. His upcoming book, Diamonds Everywhere, will be released on October 12, 2023.