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The JWST is already delivering on its promise to transform cosmology

Almost a year after its first images were released, the James Webb Space Telescope is living up to the hype, and its price tag, by revolutionising our understanding of the universe
What looks much like craggy mountains on a moonlit evening is actually the edge of a nearby, young, star-forming region NGC 3324 in the Carina Nebula. Captured in infrared light by the Near-Infrared Camera (NIRCam) on NASA???s James Webb Space Telescope, this image reveals previously obscured areas of star birth. Called the Cosmic Cliffs, the region is actually the edge of a gigantic, gaseous cavity within NGC 3324, roughly 7,600 light-years away. The cavernous area has been carved from the nebula by the intense ultraviolet radiation and stellar winds from extremely massive, hot, young stars located in the center of the bubble, above the area shown in this image. The high-energy radiation from these stars is sculpting the nebula???s wall by slowly eroding it away. NIRCam ??? with its crisp resolution and unparalleled sensitivity ??? unveils hundreds of previously hidden stars, and even numerous background galaxies. Several prominent features in this image are described below. ??? The ???steam??? that appears to rise from the celestial ???mountains??? is actually hot, ionized gas and hot dust streaming away from the nebula due to intense, ultraviolet radiation. ??? Dramatic pillars rise above the glowing wall of gas, resisting the blistering ultraviolet radiation from the young stars. ??? Bubbles and cavities are being blown by the intense radiation and stellar winds of newborn stars. ??? Protostellar jets and outflows, which appear in gold, shoot from dust-enshrouded, nascent stars. ??? A ???blow-out??? erupts at the top-center of the ridge, spewing gas and dust into the interstellar medium. ??? An unusual ???arch??? appears, looking like a bent-over cylinder. This period of very early star formation is difficult to capture because, for an individual star, it lasts only about 50,000 to 100,000 years ??? but Webb???s extreme sensitivity and exquisite spatial resolution have chronicled this rare event. Located roughly 7,600 light-years away, NGC 3324 was first cat
The edge of a nearby, young, star-forming region NGC 3324 in the Carina Nebula.
NASA, ESA, CSA, STScI, Webb ERO

A REVOLUTION in our understanding of the universe is coming. Like so many previous upheavals, it is currently unclear exactly what the trigger might be. But what is clear, almost a year on from the release of its first images, is that the James Webb Space Telescope’s observations of far distant galaxies are the most likely source of transformational insights.

Yes, this is precisely what JWST was designed for. But it is worth remembering that before its launch, which came years later than planned and after the budget had spiralled out of control, some astronomers were privately speculating on what progress their science could have made if only JWST’s gargantuan budget had been apportioned to a series of smaller missions.

Now, there can be no doubt that the $10 billion telescope has delivered on its game-changing promise. It has peered inside nearby star-forming regions, revealed stars in their death throes and successfully probed the atmospheric composition of planets far beyond our solar system. But it is the images of the very distant universe that contain the seeds of cosmological revolution.

Astronomers are now able to analyse in unprecedented detail galaxies dating from just a few hundred million years after the big bang. As we explore in our feature “What the huge young galaxies seen by JWST tell us about the universe”, what they are finding is casting our best explanations for how the universe evolved into doubt. That story is full of twists and turns. But even if the current model of cosmic evolution escapes this latest challenge, there will be more to come as JWST’s data haul continues.

A single image recently captured by the telescope shows 45,000 galaxies, 700 of which are brand new discoveries and some of the youngest galaxies ever seen. Any of these has the potential to add to the conundrum facing cosmologists.

Either we don’t understand how galaxies form or we don’t understand how the universe came to be the way it is – or both. Not bad for a telescope that some thought was a colossal waste of money.

Topics: Astronomy / James Webb space telescope / Universe