By: Alexandra Weitz
The waiting time is over. The first scientific image, taken by NASA’s James Webb Space Telescope, has already been published, to the surprise of astronomers. US President Joe Biden released the historic image, the deepest astronomical picture of the distant universe, during a press conference at the White House on Monday. NASA will release more images on July 12.
The first image, which was closely guarded before its unveiling, shows the telescope’s transformative capabilities. The image shows thousands of distant galaxies in the constellation of Flying Fish, fainter than any seen before, in a patch of sky no larger than that covered by an arm’s length of sand.
When publishing the image, Biden said it showed “the oldest documented light in the history of the universe, from more than 13 billion — let me say that again — 13 billion years ago.” “It’s hard to even comprehend,” he added.
“I’m totally amazed,” says Vivian Yu, an astronomer at the University of California, Irvine. “I can’t help but stare at the picture and try to understand what all these smudges are and why they are there,” she says.
Scientists expect Webb, the largest telescope ever launched into space, to revolutionize the study of the universe. The first batch of images to be released, including the deep field snapshot, were chosen to include all of the observatory’s main scientific objectives: the early universe, the evolution of galaxies and stars, and extrasolar planets.
transforming telescope
Unlike the Hubble Space Telescope — one of the largest and most famous space telescopes — Webb primarily detects infrared wavelengths. By studying infrared lights, it can penetrate the dust clouds obscuring nascent stars and can go deeper into the universe than ever before. The Web “isn’t the second Hubble,” says Zolt Levi, a retired astronomer and image processor who has worked for decades on Hubble images. “It’s really a completely different telescope.” “What we are looking at is an invisible light,” he adds.
Galaxies located very far from Earth can only be seen at infrared wavelengths, because the expansion of the universe has converted their light from the visible part of the electromagnetic spectrum to infrared. The first deep-field Web images show this massive effect around a cluster of galaxies known as SMACS 0723, which lies about 4 billion light-years from Earth. The clusters’ gravity bends and the light from the objects behind them amplifies, allowing astronomers to peek at very distant objects.
“What catches my attention are the distorted galaxies,” says Lisa Dang, an astronomer at McGill University in Montreal, Canada. “It looks like it’s not the other galaxies that we know of,” she adds.
The first image of the Webb telescope shows galaxies that may be more than 13 billion years old, going back roughly to the Big Bang that created the universe 13.8 billion years ago. It brings to mind many of the iconic deep-field images taken by Hubble. The first of those images, made over 10 days over the Christmas holidays in 1995, revealed that an apparently empty patch of sky was dotted with thousands of previously unseen galaxies. It took just 12.5 hours to compile the Webb telescope’s first image, compared to the weeks it took Hubble to observe other deep fields.
Webb also specializes in spectroscopy, the study of how light interacts with matter at different wavelengths. The infrared spectra of astronomical objects that Webb will produce can reveal what the objects are made of in chemical terms — to a degree inaccessible to images. “This is where you’re going to come out with some really exciting science,” says Elizabeth Kessler, a historian at Stanford University in California who has studied the aesthetic impact of Hubble images.
Webb’s first scientific images come as a breather for the telescope project, which has suffered years of delays and cost overruns worth billions of dollars. Webb was initially conceptualized in 1989, and eventually cost NASA nearly $10 billion. It is the most complex space observatory ever. His initial 6.5-meter-wide mirror had to go folded, and then open like a butterfly that spreads its wings through a series of unnerving maneuvers. Engineers had to test its tennis-court-sized sunshade — made of ultra-thin layers of polymer film coated with aluminum — several times to make sure it would propagate properly and thus protect telescope instruments in the deep freeze of outer space.
Partners NASA, the European Space Agency, and the Canadian and European Space Agency have contributed nearly another billion dollars in total to make the telescope a reality. Webb was eventually launched in December 2021 and spent six months preparing its tools for science; It is expected to serve for at least 20 years.
The world is watching
The telescope was named “Webb” after James Edwin Webb, who ran NASA during the height of the Apollo lunar exploration program in the 1960s. Some astronomers have called for the telescope to be renamed, given that James Webb held a prominent leadership role in the US State Department in the late 1940s and early 1950s, when the department was at the fore in US government efforts to identify gay and lesbian employees and shootings on them. NASA stated that it had no evidence to justify changing the name of the telescope. Its acting chief historian, along with another historian, continues to research the matter, and a report on their findings is expected soon.
The first images from the Web represent only a small part of the science that will make it accessible. It took more than 120 hours of monitoring to capture these images over the past few weeks. Future studies include exploration of Jupiter and Saturn, faint young stars known as red dwarfs, distant galaxies colliding with each other, and hot, rocky planets around other stars. Yu, who handles observational time matters on Webb, already expects to get her first data from the telescope on Thursday. That’s when the Webb team will upload observations of galactic mergers to a website for her and her colleagues to access.
Levi remembers working on some of Hubble’s more famous versions of images, such as posting photos taken after astronauts visited the Earth-orbiting telescope to upgrade its instruments. “You know the whole world is watching,” he says, “and you’d better communicate that,” and Webb seems to have done just that. “It works better than anyone expected,” Levi says. He adds, “This is wonderful.”