First JWST images excite and relieve astronomers

GREENBELT, Md. — NASA released the long-anticipated first science observations from the James Webb Space Telescope July 12, the culmination of decades of work and the start of a new era in astrophysics.

The observations, released during an event at NASA’s Goddard Space Flight Center here a day after the unveiling of one image at a White House event, illustrated the capabilities of the $10 billion space telescope from analyzing the atmospheres of exoplanets to detecting hundreds of galaxies in the early universe.

“The world’s vehicle for deepest space exploration is open for business,” Eric Smith, JWST program scientist at NASA Headquarters, said at a media briefing.

The observations released at this event include images of the Carina Nebula, a star-forming region previously observed in lower resolution by the Hubble Space Telescope; the Southern Ring Nebula, a set of gas and dust rings produced by a dying star; Stephan’s Quintet, a set of five galaxies whose JWST image reveals new details about interactions among them; and a spectra of the exoplanet WASP-96 b that revealed the presence of water vapor in the atmosphere of this “hot Jupiter” world. They join the “deep field” image that discovered distant galaxies released at the White House event July 11.

The release of the observations became a celebration as a standing-room-only audience in a Goddard auditorium cheered each new image or spectra as well as the scientists, engineers and other involved in the mission.

Scientists, some of whom have been involved with JWST for years or even decades, said they were still stunned by the quality of the initial observations, demonstrating that the telescope was performing better than specified.

Jane Rigby, JWST operations project scientist at Goddard, said the telescope’s performance became clear with some of the first focused images it returned during the commissioning process. “We have an amazing engineering team and, across the board, we beat spec,” she said. “It was a combination of being giddy in the room, looking at the data, and then going have a little sob because it works.”

“I’m a scientist and have been working on this project for 20 years, so we should expect what we saw. But no,” recalled René Doyon, principal investigator for JWST’s Near-Infrared Imager and Slitless Spectrograph at the University of Montreal. “Several times over the last six months I nearly broke my jaw over what I saw, these incredible images.”

The quality of the observations confirmed to them that JWST stands ready to reshape much of astronomy through infrared images and spectra. “How could you not discover stuff if you’re 100 times more powerful than previous telescopes?” said Rigby. “This is going to be revolutionary.”

Southern Rung Nebula
Two views of the Southern Ring Nebula taken by the Near-Infrared Camera (left) and Mid-Infrared Instrument (right) on JWST. Credit: NASA, ESA, CSA, and STScI

It may take astronomers some time to push the limits of JWST’s capabilities. The telescope has started the first round of science observations, called Cycle 1, based on proposals submitted before the telescope launched. “They couldn’t know just how good Webb was going to be when they wrote those proposals,” Smith said, resulting in some conservative estimates of the number of objects they could see or exposure times.

He expects astronomers to be more aggressive when the call for proposals for Cycle 2 comes out late this year. “People will be much more adventurous because they know just how good the facility is.”

They and others will get more of a feel for the telescope’s performance July 14, when NASA releases 40 terabytes of data collected during the commissioning process, such as raw images and spectra. That will include the telescope’s first observations of solar system objects, said Klaus Pontoppidan, JWST project scientist at the Space Telescope Science Institute. He said they were not included in the original early release observations to ensure the telescope could track moving objects properly.

While astronomers were elated with the performance of JWST, they and others were also relieved that the telescope, which cost billions more than expected and launched years behind schedule, is working. “I am so thrilled and so relieved,” said John Mather, senior project scientist for JWST at NASA Goddard and a Nobel laureate in physics for studies of the cosmic microwave background.

Asked after the event what was most striking about the early release observations, he said it was the telescope’s performance. “To me it was that all works. Everything works,” he said. “It’s got better image quality than we promised, it’s more sensitive than we promised, and it probably will last longer than we promised.”

“We are so thrilled that it works because there was so much at risk,” he continued. “The world has trusted us to put our billions into this and make it go, and it works. So it’s an immense relief.”

Mather has been involved with JWST since 1995 and is ready to see the telescope reshape astrophysics. “I’m looking forward to surprises every day,” he said. “I’m wishing for a big surprise, something that’s out there that we never guessed would be there at all.”

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