The deepest, sharpest infrared image ever captured of the distant universe was revealed last night—a stunning display of the galaxy cluster SMACS 0723 delivered by the recently launched James Webb Space Telescope. Just a century ago scientists believed there was only one galaxy, but this image reveals thousands—all found in a tiny speck of sky comparable in size to a single grain of sand held on a finger at arm’s length by someone standing on the ground. NASA Administrator Bill Nelson explained that images like this one, dubbed “Webb’s First Deep Field,” allow us to see the universe as it appeared far in the past—the light captured from these galaxies has been traveling through space for 4.6 billion years.
The wait for Webb wasn't quite that long. But finally, more than three decades after its conception and after six months in orbit, the James Webb Space Telescope’s first full-color images are delivering an unprecedented look at our Universe. After the shot revealed last night by President Biden, scientists released four more amazing images today, the first of many incredible visuals to come.
The initial images include the Carina Nebula, a dynamic region of new star birth with at least a dozen massive stars 50 to 100 times the size of our own Sun, and the Southern Ring Nebula, a huge and expanding cloud of gas surrounding a star in its death throes. Webb also captured images of Stephan’s Quintet, a compact group of five galaxies found in the constellation Pegasus, and of the intriguing planet WASP-96b, a gassy giant some 1,150 light-years from Earth.
Astrophysicist John Mather, senior project scientist for the Webb Telescope and a Nobel Prize winner, began work on Webb back in 1995 just after he helped to measure the Big Bang and determine the age of the universe “It’s the next question,” he said as the images were revealed, “after you know how it started, what happened then?” The telescope, Mather is certain, will help provide some answers. “This is our time machine, and I’m so thrilled that we got a chance to do it.”
The roughly $10 billion telescope allows us to see deeper into space, and farther back towards the origins of our universe, than humans have ever been able to see before. Webb can observe light from the universe’s very first stars and galaxies that formed 13.5 billion years ago, just a few hundred million years after the Big Bang, and track those stars and galaxies’ evolution throughout the entire age of the universe.
Though Webb will allow us to explore deeper into space than ever before, the telescope will do so much more. Webb will pull the curtain from nebulas to see where planetary systems and stars are born, which have previously been shielded from visible light observatories by dusty clouds. Infrared light observations allow Webb to peer through that dust to reveal the birth of stars, and even see through churning gasses to the black hole at the center of our own galaxy. The telescope will also offer clearer looks at exoplanets beyond our solar system, whose atmospheres are shrouded by clouds. That will enable scientists like Mercedes Lopez-Morales to study their composition and their atmospheres to see if any of them may be like Earth—and even if they might be suitable for life.
“Looking at the universe with Webb will be like looking at a familiar photo with a different set of glasses that allow us to see new details in that photo that we had never seen before,” says Lopez-Morales, an astrophysicist at the Center for Astrophysics, Harvard & Smithsonian. “Everywhere Webb will look, we will see something new.”
Successor to the Hubble telescope, which is still operating after 30 years, the Webb is the most powerful and complex scientific observatory every built. The 25-year project, a joint effort of NASA, the European Space Agency (ESA) and the Canadian Space agency, endured numerous complications, including costs that ballooned from initial estimates of just $1 billion to $3.5 billion, a 2011 NASA budget cut, and delay after delay that left some wondering whether Webb would ever get off the ground.
But the fact that it’s now in orbit, and operational, stands as a testament to scientific collaboration on a massive scale. The awe-inspiring images Webb captures of our Universe, and the discoveries it promises about its origins and our own, are the culmination of work by some 1,200 scientists, technicians and engineers from 14 countries.
“Something like the Webb Telescope really shows what humans can do when we get together,” says Lopez-Morales. “When we put our mind to it and we persevere for years, and everybody works together, things like this can be done and to me that’s inspirational.”
NASA Administrator James Webb oversaw many breakthroughs including the Apollo missions that landed the first humans on the moon, and explorations by America’s first interplanetary spacecraft. The telescope bearing his name—to which some scientists objected because of Webb’s acquiescence with his era’s homophobic government policies—launched on December 25, 2021, when an Ariane 5 rocket blasted off from Europe’s Spaceport in French Guiana. In space it carefully unfolded a tennis court-sized protective sunshield, and a honeycomb of 18 hexagonal, gold-lined mirrors more than 21 feet across, each aligned to 1/10,000th the width a single human hair. The mirrors allowed Webb to collect large amounts of light and thus see more of space than any other instrument when it settled into orbit almost one million miles above Earth.
Using sensor systems and four different cameras the telescope works in infrared light, a wavelength just beyond what we can see, and traces thermal radiation. Our own atmosphere blocks infrared light from space, which is one reason the Webb has to operate from orbit. The telescope must also be kept very cold, -364 degrees Fahrenheit, lest its own heat interfere with the sensors. That’s achieved by its location in deep, cold space and aided by that protective sun shield.
The telescope, powered by a solar array, may be able to operate for 20 years or more. Unlike low-orbit Hubble, which can be serviced, Webb’s distance, orbiting beyond the Moon, means it has been designed to be self-sufficient during the life of the mission.
Webb’s to-do list is extremely impressive. Scientists are ready with well-laid plans to explore the early universe, chart how galaxies form and evolve over time, observe the lifecycles of stars, and delve into the mysteries of exoplanets. But the telescope’s greatest discoveries might not lie in any of these areas.
“It’s very likely that we will discover things that we cannot readily explain and had not thought about,” says Lopez-Morales. “That is how breakthroughs in human knowledge happen and so I am very excited to see what Webb’s observations will reveal to us.”