Wonder Makes Us Investigate the First Light of the Universe

The Webb Telescope helps University of Arizona researchers answer astronomy’s biggest questions.

Imagine a roomful of astronomers who spent decades preparing to launch the largest and most powerful space telescope to ever exist, and who are finally receiving the first photos and data beamed back to Earth.

That’s what happened at the University of Arizona in 2022 – and it was magic. “Everybody was just pointing at the images and going, ‘Look at that, look at that, look at that,’” Stacey Alberts, an assistant research professor at the university’s Steward Observatory, says.

The James Webb Space Telescope is lightyears more advanced than previous telescopes (pun intended) and promises to answer some of the most mystifying questions we still have about outer space. The University of Arizona helped build the telescope from the beginning. NASA allotted 13% of Webb’s total observing time to the university, and every day since it launched in December 2021, the Arizona team has felt pure wonder at what they’re beginning to learn about the universe.

“We’re starting to get the results that motivated us to stick with it for so long,” says Marcia Rieke, a professor with the university’s Steward Observatory and research-group leader for the JWST’s near-infrared camera.

“We’re starting to get the results that motivated us to stick with it for so long.”
- Marcia Rieke, a professor with the university’s Steward Observatory and research-group leader for the JWST’s near-infrared camera

Here’s a look at how the James Webb Space Telescope and University of Arizona researchers are helping answer some of astronomy’s biggest questions.

When did the first galaxies form?

The earliest galaxies found by the Hubble Space Telescope formed about 420 million years after the Big Bang. But that telescope was limited in how far it could see. Now, the James Webb Space Telescope is allowing astronomers to probe more distant galaxies by using infrared light that the Hubble telescope could not see.

NASA's Hubble Space Telescope made the Pillars of Creation famous with its first image in 1995, but revisited the scene in 2014 to reveal a sharper, wider view in visible light, shown above at left. A new, near-infrared-light view from NASA’s James Webb Space Telescope, at right, helps us peer through more of the dust in this star-forming region. The thick, dusty brown pillars are no longer as opaque and many more red stars that are still forming come into view.
Credits: NASA, ESA, CSA, STScI; Joseph DePasquale (STScI), Anton M. Koekemoer (STScI), Alyssa Pagan (STScI).

“James Webb is pushing past Hubble in terms of finding these oldest galaxies.”
- Meredith Stone, a graduate student at the University of Arizona

“James Webb is pushing past Hubble in terms of finding these oldest galaxies,” Meredith Stone, a graduate student at the University of Arizona, says. The findings so far “defy models of galaxy formation that people had made before,” Stone adds. JWST has already identified a distant galaxy that formed only 330 million years after the Big Bang, and it’s likely that even earlier galaxies will still be discovered. “When exactly that first one formed is still an open question,” Stone says. “And as James Webb keeps observing, we’ll probably keep pushing that limit as we observe more of the sky.”

Stone chose to attend graduate school at the University of Arizona specifically because of the opportunity to work on the Webb telescope. “The group has been working on the telescope since its inception basically – two whole decades now,” she says. Like Alberts, she remembers the first time the team received data and images from the telescope, a million miles away from Earth. “It was this moment of, ‘Wow, everyone’s efforts that they’ve been putting in for years and years and years are finally paying off,” she says, bonding the astronomers forever in a shared sense of wonder that propels them forward every day.

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This image taken by the James Webb Space Telescope highlights the region of study by the JWST Advanced Deep Extragalactic Survey (JADES). (Credit: NASA, ESA, CSA, and STScI, M. Zimani (ESA/Webb))

Meredith Stone, a graduate student at the University of Arizona

How have the galaxies changed over time?

Today, galaxies like the Milky Way are “pretty sedentary,” Alberts says. “They’re only forming a star or two a year, and they often have black holes that aren’t doing all that much.

But that hasn’t always been the case. In the vast amounts of time between the galaxies’ formation and the present day, “galaxies had their wild teenage years and were at their most active, forming hundreds to thousands of stars every year,” Alberts says.

JWST will help reveal how a galaxy transitions from most active to less so. The answer is likely lurking behind cosmic dust – tiny particles floating around where stars form. Researchers like Alberts need the new telescope’s powerful mid-infrared light to see exactly what that cosmic dust is doing. “We know from previous infrared telescopes that this dust is basically hiding things from our view,” she says. “There are stars being born in these huge dust clouds that we can't see, or black holes that are eating material – and they're hidden behind so much dust that we don't know where they are.”

Stacey Alberts, an assistant research professor at the university’s Steward Observatory

Alberts is energized by the idea of discovering the dust’s secrets. “We're going to have exquisite sensitivity and resolution that allows us to get a detailed look at these galaxies at different stages, as they change over time,” she says. “It’s an absolutely huge leap forward.”