If you or someone in your life needs an ego check, pick up a grain of sand and hold it up to the sky at arm’s length. That grain of sand covers about the same amount of sky as the James Webb Space Telescope’s First Deep Field image. In just this tiny speck of space, Webb revealed thousands of galaxies—each containing millions to billions of stars.
NASA unveiled the first images from JWST on July 12, showing the universe in a new light.
At 2,000 light-years away, the Southern Ring Nebula comes into focus. Webb’s image shows the dust and gas spit out from a dying star.
In the “cosmic cliffs” of the Carina Nebula 7,500 light-years away, gas and dust form new stars.
Moving deeper into the universe, an image of Stephan’s Quintet shows the merging of four galaxies 300 million light-years away, and a closer galaxy in the foreground. (Closer but not close. The foreground, in this case, is still 40 million light-years away.)
The First Deep Field shows distant galaxies and light that traveled for more than 13 billion years before reaching JWST.
The stunning images are the first results of more than three decades of planning, $10 billion and thousands of engineers and scientists from NASA, the Canadian Space Agency and the European Space Agency.
Each new ultra-detailed image creates a frenzy of scientific activity, and University of California researchers are at the forefront.
Heavenly Launch
“It is truly remarkable that it has come together so well. Everything is working better than we required, and in many cases better than expected,” says Garth Illingworth, a distinguished emeritus professor at UCSC.
Illingworth started working on the project in the 1980s when it was still called the Next Generation Space Telescope. He spoke about JWST from Baltimore, where he had just come from a meeting in the same auditorium that he attended the first science and engineering meeting for the project in 33 years ago.
Illingworth works as the U.S. lead for the Public Release Imaging for Extragalactic Research (PRIMER). He and colleagues will use Webb to peer back in time and study the formation of some of the earliest galaxies in the universe.
“We’re one of billions of stars in the Milky Way, and that’s one of billions of galaxies,” says Illingworth. “These telescopes are ways for exploring and learning about our origins, about how our planet, our Earth came about, and how the stars are formed.”
JWST captures images in the infrared, outside the range of light our eyes can see. Young galaxies often appear bluish, but as light travels through space and the universe expands, the wavelengths stretch and become redder.
By the time the light from the earliest galaxies has traveled for billions of years and reaches our solar system, it can appear infrared.
To photograph the universe in this range of light, Webb flew to a stable gravitational point a million miles from Earth and delicately unfolded a sunshield the size of a tennis court to block nearby light and keep its sensitive instruments a frigid -370 degrees F.
“It was a stunningly flawless, great launch,” Illingworth says.
The rocket, launched by the European Space Agency, placed the telescope on the exact path at almost exactly the right velocity and used very little fuel.
“So, in fact, the mission life, instead of being the really minimal five years or even the goal of 10 years, is now more than 20 years,” says Illingworth. “Other things may go wrong in that time, but we’re not going to have a problem with running out of fuel unless something weird happens with the propulsion system.”
After a successful launch, the telescope meticulously unfolded over the course of one nail-biting month.
“Every one of those really scary deployments—particularly the sunshield—worked absolutely beautifully,” Illingworth says.
Now, after six months of calibrations, Webb is sending back its first images of the universe, and they’re like nothing astronomers have seen before.
Seeing Stars
Some of the images can be placed next to those from the Hubble Space Telescope, but it’s difficult to accurately compare the two. Hubble captures images in the range of visible and ultraviolet light from an orbit about 340 miles above the Earth. This makes Hubble data different—and complementary—to Webb’s infrared images from a million miles away.
“When we’ve done back-of-the-envelope calculations, we typically come up with that it’s around 100 times better,” says Illingworth of Webb.
Add to that the fact that JWST is even more sensitive than planned, and you have a lot of data to parse.
The largest of the five public images shows Stephan’s Quintet. Nearly 1,000 images combined to create this mosaic of over 150 million pixels.
“I’ve downloaded hundreds of gigabytes of data already to a local data server,” says UCSC astrophysicist Brant Robertson.
But the data isn’t just large in quantity. It’s also unique in quality.
“It’s a new set of detectors,” says Robertson. “The cameras are different than we’ve ever had before, so we’re learning anew how to deal with some of the features of the data.”
Robertson works on the steering committee for the JWST Advanced Deep Extragalactic Survey (JADES) and the management committee for the COSMOS-Webb survey.
“One of the main points of interest for me is to try to find the most distant galaxies in the universe,” he says. “And JWST newly enables us to do that, because it’s such a sensitive telescope.”
The telescope also uses a technique called gravitational lensing to magnify distant objects. The First Deep Field image has a massive galaxy cluster 4.6 billion light years away at its center. The gravity of the enormous cluster bends space and light around it, working like a magnifying glass.
Distant galaxies behind the cluster appear warped and sometimes doubled in the image.
It took about 12.5 hours for the onboard Near-Infrared Camera (NIRCam) to take the image. The comparable deep field image from Hubble took 500 hours.
Planets Aligning
Webb’s sensitivity allows astronomers like Robertson and Illingworth to cut through the cosmic dust and look back more than 13 billion years at galaxy formations. But it also provides a clearer picture of closer objects.
Natalie Batalha, director of the Astrobiology Initiative at UCSC, will use the data from Webb to study exoplanets. Our galaxy is full of planets orbiting other stars, and Batalha worked on NASA’s Kepler mission to find thousands of them.
Now, she will use JWST to study the diversity of the Milky Way.
Batalha leads the Transiting Exoplanet Community Early Release Science Program, which observes planets as they pass in front of stars.
“When the planet is in front of the star, some of the starlight is filtering through the planet’s atmosphere, imparting a chemical fingerprint that we can see,” Batalha says.
Scientists measure the total light of the star before, during and after a planet transits in front of it, and they break the light down into a spectrum that can reveal information about the planet’s atmosphere.
In the first example released last week, JWST captured the signature of water in an exoplanet 1,150 light-years away.
Researchers will look for different molecules in the atmospheres of exoplanets and calculate ratios of atoms.
“Those ratios tell us something really interesting about how the planets formed, how they evolved, what kind of dynamic processes they underwent when they were young,” says Batalha.
The thousands of exoplanets that scientists have identified within our galaxy come in an incredible array of sizes and types.
“We’re starting to understand what drives that diversity, but it’s just the tip of the iceberg,” Batalha says. “We really want to look at the whole iceberg and understand those processes, because they will impact our understanding of planetary habitability and the propensity for life.”
Batalha says Webb likely won’t be able to detect evidence of life, but it will provide a starting point.
“We will be able to say, ‘Yes, this planet has an atmosphere,’ or ‘No, it likely does not,’” she says.
A New View
Batalha started working in exoplanet research when it first became a field, and the team she collaborates with is enormous.
“The whole week has been a flurry,” she says between pings from a 300-person Slack channel.
“When you all of a sudden gain access to a new marvel of technology that’s going to open up a bottleneck in scientific exploration, there’s usually this frenzy of activity that goes along with it, and sometimes that can be very competitive,” says Batalha.
But so far, Batalha says the environment is one of support.
“There’s something about the teamwork and camaraderie, the intensity of working with other people collaboratively, that is unparalleled in our day-to-day lives,” she says. “It makes you see the best of humanity, and it’s uplifting. It makes me hopeful.”
Batalha has one particularly special collaborator: her daughter, Natasha, who researches exoplanets at NASA.
“To be able to share this with her—have her understand exactly what I’m experiencing, and to be able to resonate with it and celebrate it together without having to say anything because it’s a shared experience—that’s really special,” says Batalha.
Whether working on the data or simply stargazing, Batalha and fellow astronomers say people should keep one thing in mind.
“Relish the beauty,” Batalha says. “That’s most important. We live in an amazingly beautiful universe.”
