Cal scientists star in Webb Telescope exploration
Astrophysicists and space buffs worldwide erupted into cheers after the perfect launch of the James Webb Space Telescope (JWST) on Christmas Day 2021. Days later, they held their collective breaths as sections of the telescope’s mirrors and sunscreen, folded inside like highly intricate origami, were deployed, concluding in full deployment on Jan. 8, 2022.
No one was more relieved and awed than Berkeley alum and Nobel Prize-winning scientist Dr. John Mather, who is also the JWST senior project scientist. In a taped National Press Club event, Mather described the long and agonizing testing process during the JWST’s development. “We made a list of about 700 things that could go wrong,” he said. The unfolding alone had 344 potential “single point failures.”
Those tests paid off. One of the most remarkable scientific achievements in history is now sending images and information back to Earth that will forever change perception of the universe. And UC Berkeley (UCB) scientists are in the forefront of multiple projects involving the JWST.
Short, non-scientific notes on ‘why the Webb?’: Despite the tremendous success of the Hubble Space Telescope, launched in 1990, its vision is limited. As a “warm” telescope, “Hubble sees ultraviolet light, visible light, and only a small bit of infrared. Many galaxies are so far away that, due to the expansion of the universe, they are moving away from [Earth] so fast that the wavelengths of their light have shifted into the infrared, far beyond Hubble’s detection capabilities,” according to www.plantary.org.
So, if humans wanted to look into the deepest secrets of the universe’s birth—and its future—a “cold” telescope would be needed, one that would not emit its own infrared light, and could use its infrared cameras to see through dust in the universe. Stars and planets form inside those dust clouds, stunningly depicted in the famous “Pillars of Creation,” new images of which were sent back from JWST very early on. The JWST is seven times as powerful as the Hubble.
Developing and launching the JWST was a joint project of NASA, the European Space Agency and the Canadian Space Agency, taking more than two decades and $10 billion to complete. Was it worth it? Definitely yes, say scientists such as Cal’s associate professor of astronomy Dan Weisz, who heads one of four UCB projects among the first approved to use the telescope, and one of two of only 13 approved as part of the JWST Resolved Stellar Populations Early Release Science Program.
Weisz is the principal investigator of the Early Release Science Program, which is establishing the scientific and technical foundation for JWST studies of resolved galaxies and star clusters throughout the local universe. His team is focusing on studying the dwarf galaxy Wolf-Lundmark-Melotte (WLM), along with two other distant systems, globular cluster M-92 and Draco II, another dwarf galaxy.
According to one of his 40 team members, Prof. Kristen McQuinn of Rutgers University, “WLM hasn’t interacted with other systems, which makes it really nice for testing our theories of galaxy formation and evolution…This makes WLM super interesting in that you can use it to study how stars form and evolve in small galaxies like those in the ancient universe.”
“We have very specific science and technical goals,” said Weisz. His team is also building software to measure space environments, which will enable other scientists, as well as the public, to evaluate JWST images, according to UCB materials. “My program is designed to enable community science,” the UCB materials quote Weisz as explaining. “There is discovery space for us, but our focus is on enabling discovery space for everyone.”
There’s a connection here to Weisz’s own story, as, according to him, far from being a “science kid” staring through a backyard telescope at the stars, he was much more interested in sports. “But I was always good at math, and discovered that in physics, I could apply math,” he said.
As a physics undergrad at Berkeley, he took Intro to Astronomy, “and got sucked into it,” kind of like into a black hole. In 2004, when he started graduate school at the University of Minnesota, a new camera had just been deployed on the Hubble. “My professor used Hubble, and I was looking at images from it,” he said. Fascinated by how galaxies form, he moved on to become a Cal faculty member, and by 2015-2016, proposals for using the still-unlaunched JWST were being solicited.
Scientists around the world were being told the telescope would launch in 2018, so he put in a proposal for “early science” use, and his proposal was accepted—only to face another three years of delay, as more potential problems were discovered and solved.
Now, “We are working to understand the nature of the universe, which is 13 billion years old,” he said. For example, “Exoplanets [which could potentially support life] exist. We can take Webb, point it at a planet and look for bio-signatures.” He can also assign projects to the more than 50 astronomy majors in his department, helping create the next generation of astrophysicists.
Three other UCB scientists—all women—also have JWST projects. As Mather pointed out at the Press Club event, “We take double-blind proposals twice a year. They are anonymous, so as not to favor old white guys.”
Prof. Imke de Pater will observe Jupiter and its moons. The distinguished professor of the graduate school and distinguished professor emerita of astronomy and earth and planetary science wrote her proposal in 2017 before her retirement from teaching, according to Berkeley News.
“She is particularly eager to take advantage of the JWST’s ability to detect mid-infrared light, which will give her access to different layers of Jupiter’s atmosphere, ones she has not been able to explore using earthbound telescopes,” reported that source.
The November 2022 National Press Club event also featured Cal’s Prof. Courtney Dressing and Prof. Jessica Lu.
Observational astronomer and assistant professor of astronomy Dressing will be studying exoplanets. “We’ve learned that systems orbiting other stars are very diverse,” she said. One of these stars is Trappist 1, a red dwarf that could have life on one of the seven exoplanets orbiting it.
According to Dressing’s UCB bio, “I am curious about how planets form and evolve with time, the frequency of planetary systems in the Galaxy, and the prospects for detecting life on planets outside of our Solar System.”
“With the JWST, we can study atmospheres and many more planets,” she said during the event. “In 2000, I was in middle school. Now, my Intro to Astronomy students are so excited about what we are learning.”
Associate professor of astronomy Lu will study black holes. “The center of our own galaxy is a massive black hole,” she said. The JWST will look at it again to explore young stars “wobbling” around it. “Why are those stars there?” and “How did they get there?” are some of the questions she hopes to illuminate. Lu is also fascinated by dark matter, the mysterious make-up of up to 85% of the universe’s matter.
“There is dark matter passing through your body right now,” noted Mather during the Press Club event.
“We hope to use nearby galaxies to understand dark matter,” said Lu.
She chuckled, recalling that in 2000-2003, while studying for her doctorate, she was told, “Don’t do anything with the JWST; it might not exist.” By 2017-2018, “we started having meetings, but the Webb was delayed again.”
Yet now, as moderator Prof. Steven Kahn, dean of mathematical & physical sciences at Cal, remarked during the event’s introduction, “We are in the Golden Age of Astronomy.”
This Golden Age is opening opportunities for Berkeley’s astronomy department to return to its tradition of “building the next generation of experimentalists,” said Lu, referring to those who engineer the equipment that enables scientists to study the universe. “We are training new people to build a spectrograph in one week,” she said. “And they can do it.”
“It’s the unexpected,” Lu emphasized, “that will change our perceptions.” Finding the unexpected will be possible for a long time with the JWST, whose perfect launch and deployment has potentially extended its lifespan for decades.
And although, as Kahn joked at the Press Club event, “Washington, DC is the biggest black hole in the universe,” funding is already in place for NASA’s next big reveal: the 12-meter Habitable Worlds Observatory, a space telescope designed to “seek out new worlds.”
“On one level, everyone wonders about where we came from,” said Weisz. Using these engineering miracles, “we can see our origins.”
To view the entire National Press Club event, and learn more about the JWST, the Berkeley connection and some of the individual projects, visit https://www.youtube.com/watch?v=2ng7bcOzuas.
