How the Webb telescope expands the world’s sense of wonder

Never before has humanity seen the cosmos like this.

Diamond-like stars dazzle in the foreground. Gas and dust erupt from cosmic collisions and appear to set the sky ablaze in rusty red hues. There are spiral galaxies, galaxies warped like pizza dough thrown into the air, merging galaxies and galaxies that appear as faint red spots so deep in the background that astronomers say the image captures the light they emitted perhaps 13.1 billion years ago.

The first images from the James Webb Space Telescope (JWST) were released by NASA this week, revealing the most detailed view of the deepest parts of our universe yet and heralding a new era of astronomy. With its infrared “eyes,” the new space telescope has revealed some of the earliest moments of the universe’s existence. This expanded view promises to reveal vital clues about cosmic mysteries that have long baffled scientists.

In the excitement over this initial burst of JWST images, scientific ingenuity is matched by sheer joy. We have literally been left in awe as photos show the unimaginably distant, near and beautiful.

“It’s fun to be able to see these images of babies of the universe,” says Brant Robertson, who heads the Computational Astrophysics Research Group at the University of California, Santa Cruz, and who is involved in several major programs that use the JWST to study galaxies. in the early universe. “But it’s not just an image. The key to unlocking that early story, to being able to write the first pages of the cosmic story of galaxy formation, is really being able to find these distant objects. The JWST can do that.”

Astronomers around the world are furiously investigating the first batch of JWST data released alongside the images. The findings they publish in the coming months could fundamentally change the way we understand our universe. But it is the photos themselves that can inspire imaginative speculation and fuel humanity’s efforts to understand the deepest reaches of the cosmos.

“People wonder what makes a good astronomer,” says Dr. Robertson. Do you have a mind for math, or maybe physics appeals to you? “Honestly, I think it’s a good imagination. You have to try to imagine what the universe was like, at great distances, in environments that are completely different from what the sun and the Earth or the Milky Way is like. How can you put your mind in a place you have never seen before? That’s why these images are so important to astronomers.”

This is exactly how Jacqueline Faherty found her way to becoming an astrophysicist. Now a senior manager of education and senior astrophysicist at the American Museum of Natural History in New York, she credits an early encounter with a cosmic photo for setting her on a career path.

When Dr. Faherty was 18 years old, she saw a Hubble Space Telescope image of the supermassive star Eta Carinae. The photo shows clouds of gas and dust rising from the eruptive star system. At that moment, she remembers thinking to herself, “’Wait a second. Is that out there? What’s that? I want to do that. I’m going to solve this. And I never looked back.”

Now, Dr. Faherty is preparing to make her own observations using the new space telescope. She studies the coolest objects emerging from the process of star formation and will direct JWST’s infrared detectors at these strange worlds to examine the contents of their atmospheres, among other details. It’s possible, says Dr. Faherty, that the JWST could reveal clues as to whether extraterrestrial life might exist on one of those cold, cold worlds.

Infrared light tracking

The JWST was designed to be able to observe the oldest and coldest things in the universe. Astronomers largely detect celestial objects from the radiation they emit, with telescopes tuned to pick up signals at specific wavelengths. Hotter objects tend to emit radiation with shorter wavelengths, such as ultraviolet light, while cooler objects emit infrared light, which is not visible to the human eye.

Objects further away from us also tend to appear in the infrared, since distance causes the wavelength of their light to lengthen. And, as the universe expands, the farthest objects we can see are also the oldest, and their light takes billions of years to reach JWST’s detectors.

“That’s what we built the telescope for,” said Jane Rigby, JWST operations project scientist and astrophysicist at the Laboratory for Observational Cosmology at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. The first JWST image revealed by NASA, containing the galaxy cluster SMACS 0723, looks deep into the universe. In it, there are galaxies a few billion years old in the foreground and faint red ones “scattered like jewels” in the background that appear to us as they did 13 billion years ago.

However, the new JWST images didn’t just reveal a detailed first look at the early days of the universe. The new space telescope also directed its infrared “eyes” at objects closer to our corner of the cosmos to illuminate details that were hidden from astronomers who previously looked at other wavelengths, revealing a new layer of the cosmos to humanity.

Images showing the progress of Hubble

The Hubble Space Telescope, which began its mandate 32 years ago, focused primarily on optical wavelengths of light. Dubbed “the people’s telescope,” Hubble brought images of the cosmos into popular culture and piqued the curiosity of many, including Dr. Faherty. One of the most famous images taken by Hubble was that of the ‘cosmic cliffs’ of the Carina Nebula, which is located about 7,600 light-years from us. (Eta Carina is also found in this nebula.) The hazy glow of the gas and dust that make up the nebula is contrasted against a milky sky punctuated with the glitter of stars in the Hubble’s iconic image. But the JWST shot of ‘Cosmic Cliffs’ isn’t blurry. The edges of the nebula are sharp, many more bright stars appear, and the gas and dust in this stellar nursery appear to have distinct mountains and valleys.

JWST also captured a new view of a dying star system as both near-infrared and mid-infrared observations revealed details about the two stars locked in a tight dance in the South Ring Nebula, which is about 2,500 years away. light. far.

In a group of galaxies called “Stephan’s Quintet,” the JWST captured the bright red merger of two of the five galaxies. The space telescope also revealed the signature of an active black hole at the heart of one of the galaxies, giving scientists the opportunity to study in detail how supermassive black holes consume the material around them.

water on an exoplanet

The four images were not all that was revealed from the initial JWST discoveries this week. NASA also announced that the space telescope captured the signature of water in the atmosphere of a giant exoplanet called WASP-96 b, which is approximately 1,150 light-years from Earth. Scientists also found evidence that there are clouds and haze in that world’s atmosphere, demonstrating the space telescope’s ability to observe the chemistry of exoplanets in the search for other habitable worlds.

The JWST is not the first space telescope to observe the infrared. The Spitzer Space Telescope, which ended operations in 2020, also observed that wavelength. While it was “the little engine that could and did do a lot in infrared astronomy,” says Dr. Faherty, the JWST has much better resolution than Spitzer for revealing details of previously invisible objects in the deepest parts of the universe. .

Astronomers are already poring over the data and images, says Dr. Robertson. They are using the images not only for inspiration, but as a tool to contextualize and confirm the discoveries they are making in the data.

Roles for citizens

Dr. Robertson himself has uploaded the images in a format that people can approach and interact with, and invites anyone from any scientific or non-scientific background to explore them. Most of the raw data is also available online, and he hopes “young astronomers around the world will be able to make discoveries in these images.”

With the JWST looking at all the depths of the universe and all sorts of different celestial objects, there are plenty of discoveries to be made. Dr. Faherty has already been collaborating with citizen scientists on her proposals for time using the JWST through her Backyard Worlds: Planet Nine citizen science project.

“If you’re excited about JWST images, join a citizen science project,” he says, “because people like me will find a project for you and you might find something.”

JWST images are already reaching viewers who might not normally be interested in astronomy, adds Dr. Faherty. In the future, “children can very well remember when they saw images of JWST on Instagram or TikTok,” she says. “In the age of social media, these images are amplified in a big way.”

Astronomers say they expect much more from JWST, and soon.

“The amazing thing about Webb is the speed at which we can produce discoveries,” Dr. Rigby said during the NASA broadcast. With Hubble, imaging the deep field took two weeks of continuous work, but “with Webb, we took that image before breakfast,” he said. Everything revealed this week took just a week of observation time with JWST, he said. “We’re going to make discoveries like this every week.”

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