How the James Webb Space Telescope changed astronomy this year

A year ago, the James Webb Space Telescope began its journey through space.

“JWST launched on Christmas Day and then took six months to open,” says Jane Rigby, NASA astronomer and Operations Project Science Specialist.

After an initial calibration period, the telescope began collecting data. And the first results surprised astronomers.

“I downloaded the data and it’s like I’m sitting in my pajamas … you know, it’s a pandemic, we’re all working from home,” Rigby said. “I gathered that information and just started paging through it, going through it. And it was great.”

The telescope is only five months into its science mission, and it’s already changing astronomy. The telescope’s instruments have allowed it to capture previously unseen planets, stars, and nearby and distant galaxies.

NPR spoke with three astronomers in different fields of astronomy about how JWST is advancing research in their areas of expertise. All agree that JWST is a game changer, and there is still more groundbreaking research to come

“Call systems come out right away and they’re great”

The image of space shows a bright star emitting light rays at the top of the photo and a small, bright white planet with two white, almost transparent rings at the bottom of the photo.  The background is a black sky.

JWST’s images of Neptune are the clearest pictures of the planet’s rings taken in decades. The bright blue object is Triton, Neptune’s large frozen moon.

Heidi Hammel is a planetary astronomer and interdisciplinary scientist at the JWST Project. He joined the team in 2002 because he wanted to study the planet Neptune.

In September, JWST trained its mirrors on the ice giant.

“When I first saw the image on my computer screen, I was very emotional,” Hammel said. “First I started crying, then I started screaming and calling all my relatives to look at this picture!”

Before JWST, astronomers had never clearly observed Neptune’s ring system, Hammel said. The Voyager spacecraft flew past Neptune in 1989, but was able to capture only the brightest parts of the planet’s rings.

The JWST instruments saw the rings with unparalleled clarity.

“Boom! The ring systems come right out and they’re beautiful,” Hammel said.

“Like stepping into the real world from virtual reality”

Beyond our own solar system, JWST has also helped astronomers observe the oldest and most distant known galaxies.

“I’ve been looking at simulated data for years, trying to mimic what JWST would see. So when I saw the data for the first time, it was like stepping from virtual reality into the real world,” said Brant Robertson. Professor of astronomy and astrophysics at the University of California, Santa Cruz.

Robertson is among the team of researchers who discovered the oldest galaxies ever observed. JWST’s instruments allowed his team to identify galaxies up to 13.4 billion years old—just a tiny fraction of the universe’s lifetime, less than 400 million years after the Big Bang.

The image of space shows many different spots and dots in different colors, but mostly round.  They are against the black sky.

Hundreds of galaxies are visible in this image, which combines near-infrared colors taken by the Webb Telescope with those from Hubble.

(NASA, ESA, CSA, A. Pagan (STScI) and R. Jansen (ASU))

“By finding these very early galaxies, we can learn something about our history, the history of the universe in general, but also about our home in particular,” Robertson said.

While older telescopes like Hubble gave astronomers a glimpse of what’s out there, JWST expanded the scope of what science is possible, Robertson said.

“Before this telescope, almost everything we did was impossible”

JWST’s Operations Project Specialist Jane Rigby also uses the telescope to study distant galaxies.

By combining this with JWST — a natural phenomenon called gravitational lensing — which Magnifies the light from galaxies that Rigby observed, he was able to cut through cosmic dust to study how stars form in these galaxies.

An image of the space shows an hourglass-shaped body of translucent dust and gas in bright orange, yellow, pink, purple and blue colors.  It is against the black sky.

Webb photographs a protostar, the beginning of a new star. The “hourglass” of clouds of dust and gas is visible only in infrared light, the wavelengths in which Webb specializes.

“Before this telescope, almost everything we did was impossible,” Rigby said.

Rigby says that the Hubble instruments could not see these galaxies through the dust that obscures them. In addition, JWST’s instruments allow it to study the material composition of these galaxies through spectroscopy, a method astronomers use to determine the chemical composition of objects in space.

“We’re learning where stars form in these lensed galaxies in a way that’s ridiculously impossible with any other telescope,” Rigby said.

JWST has already proven to be an incredible tool for astronomers, Rigby said, but its biggest discoveries are yet to come.

“We’re starting to get this flood of papers announcing discoveries,” he said. JWST is used to study planets in our own solar system, the atmospheres of planets in other solar systems, how stars die, how galaxies evolve and more, Rigby said.

The image of space shows an oval-shaped, semi-transparent body of dust and gas with a bright white dot emitting light rays in the center.  The body of the goose is mostly white, then orange and yellow on the outer edges.  It is against the black sky.

A dying star, pictured here in unprecedented detail, is ejecting gas and dust. Photos like this one from JWST will help us understand how stars evolve.

Although JWST is significantly more powerful than previous telescopes, Rigby says astronomers can still use Hubble to complement JWST’s observations.

“JWST was built to do things Hubble couldn’t do in many ways, so they play very well together,” Rigby said. “The pitcher and the catcher on your baseball team do different things.”

Rigby said the telescope has enough fuel on board to last more than 20 years in space, so it could exceed its planned minimum five-year mission.

“I think next year will be even more exciting than this year,” Rigby said.

After all, it will take time to sift through the data collected by the James Webb Space Telescope and see how much it can change our understanding of the many mysteries of the universe.

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