The next great era of astronomy truly began this morning. After nearly three decades of troubled development and $10 billion in spending, a pulse-pounding launch on Christmas Day in 2021 and a nail-biting half-year of delicate preparations in deep space, the James Webb Space Telescope has at last delivered a complete set of first full-color images. President Joe Biden himself offered a sneak preview yesterday evening from the White House, revealing what is destined to be the most iconic picture from the set.
“These images are going to remind the world that America can do big things, and remind the American people – especially our children – that there’s nothing beyond our capacity,” President Biden said during the event. “We can see possibilities no one has ever seen before. We can go places no one has ever gone before.”
Constructed by NASA, as well as Europe’s and Canada’s space agencies, Webb is controversially named for a former NASA administrator, and it is the most powerful off-world observatory yet built. But for a time, the observatory was more of a cruel joke among astronomers: the technical demands of its development pushed the project so far over budget and behind schedule that many suspected it would never launch at all. Now it promises to revolutionize our understanding of the cosmos during a mission that could stretch into the 2040s. Each of the telescope’s latest images has marshaled the might of at least one of Webb’s four main instruments, as well as its giant 6.5-meter segmented primary mirror, composed of 18 coffee-table-sized hexagonal slabs of gold-plated beryllium that folded together like a piece of origami to fit within an Ariane 5 rocket. Perched 1.5 million kilometers from Earth and shaded by a multilayered sunshield as big as a tennis court, the telescope’s kit is cooled close to the temperature of the vacuum of space. That deep freeze allows it to see—or rather feel—the infrared glow of far-flung galaxies, nearby planets and everything in between.
Even before today’s official images were released, earlier pictures taken to guide Webb’s complex deep-space commissioning hinted at the observatory’s stunning capabilities. Simple snapshots of a star obtained by the telescope’s workhorse instrument, the Near Infrared Camera (NIRCam), also serendipitously included more than 1,000 “photobombing” background galaxies that would have been too faint to simply swim into view in any other observatory’s optics. These and other preliminary tests, says NIRCam’s principal investigator Marcia Rieke of the University of Arizona, have shown that “all of Webb’s instruments are achieving even better sensitivities than we projected” and that the performance of its mirror is similarly exceeding expectations. With these new images, Rieke says, “we are now seeing that the science returns are probably going to be even greater than we had dared to hope.”
All Eyes on Webb
Designed to showcase the breadth and depth of Webb’s cosmic vision while also serving as enrapturing eye candy, these first science images indeed do not disappoint. Among them are unprecedentedly detailed views of the Carina Nebula—a tumultuous stellar nursery about 7,600 light-years from Earth that is illuminated by the bright, brief lives of massive stars—as well as a portrait of the Southern Ring Nebula, a more than 2,000-light-year-distant dying sun expelling its element-enriched outer layers as turbulent shrouds of glowing gas. The cycle of celestial creation and destruction continues in other images from some 290 million light-years out that capture the interacting galaxies of Stephan’s Quintet, which are sparking intense bouts of star formation within gigantic intergalactic shockwaves as they slowly merge into a single larger galaxy.
But the full scope of Webb’s audacious scientific ambit is best revealed through two other images—one striking and one subtle.
The subtle one is a spectrum—essentially just a squiggly series of peaks and valleys recording how various wavelengths of light shine through the upper atmosphere of WASP-96b, a scorched exoplanet with half the mass of Jupiter that orbits a star more than 1,000 light-years away once every 3.4 days. Such spectra are hardly images at all but can reveal an object’s bulk composition, says Knicole Colón, Webb’s deputy project scientist for exoplanet science at NASA’s Goddard Space Flight Center. “Webb will provide the first relatively high-resolution infrared spectra of exoplanet atmospheres, opening a new chapter in the era of exoplanet characterization,” she adds.
A full 70 percent of the observatory’s first year of planned observations involve taking spectra of some kind for targets all across the universe, according to Klaus Pontoppidan, Webb’s project scientist at the Space Telescope Science Institute. Most of those measurements will chart the chemical evolution of galaxies across cosmic time and within star- and planet-forming disks scattered throughout the Milky Way. But some will instead record spectra for a handful of small, temperate worlds around nearby stars to sniff out the presence of atmospheric carbon dioxide, water vapor, methane and other compounds associated with habitability and life. Unlikely though it may be, one of Webb’s hard-won spectra could in principle provide the first compelling evidence that we are not cosmically alone.
The most striking of the first images has little to do with the search for extraterrestrial life, yet is still so spectacular that it wooed the White House into a last-minute change of plans, allowing President Biden to share in the observatory’s glory by presenting it to the world a day earlier than NASA originally intended. Captured by NIRCam, this image is Webb’s “deep field” observation of SMACS 0723, a crowded region of the cosmos strewn with galaxies like so many jewels on black velvet. Most of those galactic jewels are more than four and a half billion light-years away, but they are a foreground distraction to the true treasure, which can be found in the dim, distorted shapes lurking in the darkness beyond. The entire galaxy-packed image spans a stretch of sky approximately the size of a sand grain held at arm's length. (See a high-resolution zoomable version here.)
Contemplating the Cosmic Dawn
The collective bulk of SMACS 0723’s clustered galaxies is so great that it warps the surrounding space, forming a bubblelike “gravitational lens” through which the fainter light of much more distant background galaxies—perhaps among the very first luminous objects in the cosmos—is warped and magnified into view. Such images make Webb less a telescope and more a time machine, for in creating them, it gathers light from eons ago, sent forth only a few epochal moments after the big bang, during the so-called “cosmic dawn” when the first stars and galaxies are thought to have formed. The Hubble Space Telescope and other predecessor facilities have taken similar images but lacked the sensitivity to detect those most distant galaxies that Webb can see in droves. These objects appear not only intrinsically faint and minuscule in the sky but also lie so far back in the past that the subsequent expansion of the universe itself has stretched out, or “redshifted,” the wavelengths of their emitted light into the infrared. They are the elusive quarry Webb was meant to hunt from the project’s very inception in an obscure 1996 technical report that referred to it, after Hubble, as simply the Next Generation Space Telescope.
Knowing just how far back Webb has seen with the SMACS 0723 deep field, Rieke says, will require additional observations to measure redshifts for each gravitationally lensed galaxy. But what’s already certain is that this is the deepest, clearest infrared image of the universe yet made—a fact not lost on those who helped create it. Cryptically referring to the image in a teaser press conference weeks before its release, Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate, stated that viewing Webb’s first visualizations had almost moved him to tears.
It was Pontoppidan, tasked with downloading and then distributing Webb’s raw data to the 30-person team that prepared its inaugural images, who was the very first to see the SMACS 0723 deep field. For a brief time, from his home office he gazed farther into the universe’s luminous depths than any other earthling ever had before. “I spent probably two full hours just staring at it,” he recalls, “sitting in my basement, in front of my computer screen, feeling very alone in the world.” The image elicited a similar hush when the rest of the team saw it during an in-person group meeting. “It was moving,” Pontoppidan says. “All the people in that room were just quiet for a long time.”
To see this image—to be, if even for a moment, lost in its ineffable galaxy-studded depths—is to appreciate just how far we have come. Webb is so technically daunting that, in the words of Keith Parrish, the telescope’s observatory manager at Goddard, it “did not want to exist.” Yet it of course endured, surviving numerous near-death experiences on its decades-long path to the launchpad and then, against all odds, successfully running a gauntlet of make-or-break deployments beyond Earth. Viewing its first dedicated deep-field image reveals a journey even more epic, and tinged with what may best be called the divine: glimpsing those newborn galaxies ablaze with the light of the first stars, we see our earliest cosmic ancestors emerging from the void, holding the shape of all things to come—the Milky Way, the sun, Earth and us—latent in their ancient majesty. Fittingly, the more one knows about Webb’s origins—and the more it reveals about ours—the more miraculous its existence and our own appear to be. For those attuned to perceive it, the great weight of this knowledge comes to rest within a wordless contemplative space, making the heart tremble as readily as any sermon or hymn.
“Astronomy has an inherent ability to make us think bigger—to think outside ourselves and consider our place in the universe,” says Amber Straughn, Webb’s deputy project scientist at Goddard. “Exploration and discovery tap into something deep inside all of us—they are key parts of what makes us human. This telescope is going to change how we understand the universe in ways we haven’t even dreamed of.”
The Road Ahead
The observatory’s success, Pontoppidan whimsically muses, speaks against bleak, all-too-common assessments of our present moment on Earth being the darkest time line in some notional multiverse. “Webb’s launch and early commissioning up through now can be seen as a split between two radically distinct worlds,” he says. “There is a world where we put $10 billion into this complicated origami observatory, and it just collapsed in on itself in a huge fiasco. And then there is the world we’re remarkably inhabiting now, where this thing actually worked! Where we go from here with Webb—with astronomy in general—is to a very different place.”
And as most every astronomer will eagerly remind you, the telescope’s transformative mission has scarcely even begun. “It’s one thing to predict its power, but it’s another to see what Webb can produce almost without even trying,” Colón says. “These first images only scratch the surface of what Webb is capable of.”
Hubble’s deepest image of the universe, Pontoppidan notes, took 14 days of dedicated staring at the same spot on the sky. Webb’s record-breaking deep-field image—along with all the others released today—collectively emerged from a total of just five days of observing time. “You know, we weren’t trying to scoop anybody or make the forever-deepest field,” he says. “Whatever we have done, other scientists using Webb will now do even better—and quickly.”
That astounding pace, says Jane Rigby, the telescope’s operations project scientist at Goddard, makes Webb “a Bugatti sports car that has been built in a horse-and-buggy world.”
“It’s like the difference between traveling three versus 300 miles per hour,” she says. “And now we’re going to actually take this thing out on the racetrack. So how deep, how far can we go when we crank it up and push it hard? I’m as excited as anyone else about these first images, but my heart is with the thousands and thousands hours of competitively selected, peer-reviewed science we are about to undertake in Webb’s first year of observations.”