The first color image covered a patch of sky about the size of a grain of sand. But while the “deep field” photo captured by the James Webb Space Telescope (JWST) and unveiled to the public on Monday may have been only a sliver of the cosmos, it revealed a groundbreaking view of immense importance: the most detailed view of the early universe to date, just a few hundred million years after the big bang.
“We’re looking back more than 13 billion years,” NASA administrator Bill Nelson said of the photo that shows a galaxy cluster teeming with thousands of never-before-seen stars. “Light travels at 186,000 miles per second,” he explained, “and that light that you are seeing from one of those little specks has been traveling for over 13 billion years.”
Tuesday, NASA revealed a new batch of images taken by its $10 billion Webb telescope, the largest most powerful space observatory every constructed. Among the jaw-breaking photos: a group of five galaxies called Stephan’s Quintet; the edge of a star-forming region in the Carina Nebula featuring what the space agency described as a landscape of “mountains” and “valleys” speckled with stars; and a stunning view of the second, dusty star at the center of the Southern Ring Nebula.
“I was absolutely astonished,” Nico Cappelluti, an assistant professor of astrophysics in the University of Miami College of Arts and Sciences, said of the Webb telescope’s first images, which he saw at his family home in Italy, where he is conducting research on supermassive black holes with colleagues in Bologna.
“What I immediately noticed was the improvement in the depth and sharpness of the images and the huge extension of the central elliptical galaxy showing signatures of tidal forces,” Cappelluti explained. “And yes, galaxies produce tides just like the moon.”
The Webb telescope comes with a hefty price tag, and at one point, it was uncertain whether the project would even get off the ground. But now that the telescope is orbiting the sun a million miles from Earth, looking farther back in space and time than ever before while sending back images in stunning clarity, the endeavor promises to unlock mysteries of the cosmos that have puzzled astronomers for decades, according to Cappelluti.
“The first billion years after the big bang are very important,” he said. “It is in the first billion years that the first stars appeared, and they started producing all the heavy elements that we see today and that are fundamental for life. We call this epoch the Dark Age. And it was during this period that the universe also underwent a very important phase transition. It changed from being made by neutral atoms to being completely ionized,” he added. “We believe that the first stars and black holes were the reason behind this reionization. The Webb telescope will tell us what actually happened and will allow us to rewrite cosmic history.”
JWST is far superior to the Hubble Space Telescope, which launched into low Earth orbit in more than three decades ago and is still in operation. Webb has a bigger primary mirror—6.5 meters in diameter, compared to Hubble’s, which is 2.4 meters. And it is that size differential that gives the Webb greater light-gathering capability.
A collaboration between NASA, the European Space Agency, and the Canadian Space Agency, the Webb Telescope also features more angular resolution than Hubble, allowing it to capture crisper images, according to professor of physics Josh Gundersen, whose research interests range from our own galaxy, the Milky Way, to the cosmos, and the Big Bang.
It also extends wavelength coverage into the infrared, giving it the ability to see cooler objects as well as objects that are otherwise obscured by dust. “What is even more amazing is that there’s a lot more capability to the instrument than even meets the eye,” Gundersen said.
Searching for signs of life on exoplanets could be the Webb telescope’s most important mission, said Alessandro Peca, a University of Miami Ph.D. student studying physics and astronomy.
“In fact, the JWST will be able to see the molecules present in the atmospheres of planets outside our solar system. For example, we will be able to understand on which and on how many exoplanets life similar to ours may exist,” said Peca, who watched NASA’s livestream of the big reveal of the Webb telescope images. “This is all very exciting.”
Cappelluti, who calls the telescope the “greatest engineering feat in the history of astronomy,” is competing for observation time on the groundbreaking instrument, hoping to learn more about black holes. “We will also use the public data that will be soon released to the community to run a program together with the Chandra X-ray Observatory to find signatures of the first black holes,” he said. “Our view of the universe is about to change forever.”
