Reaching for the Stars (and the Exoplanets)

NASA astrophysicist Christopher Stark (Ph.D. ’10, physics) is on a mission to broaden our horizons in space

Christopher Stark (Ph.D. ’10, physics) grew up in Mt. Pleasant, Iowa, a small midwestern town known in part for one of its most famous natives, James Van Allen, a physicist who was very influential in the development of space science in the United States and even graced the cover of Time magazine in 1959. 

“Van Allen discovered the Van Allen radiation belts around Earth and I feel like this was sort of common knowledge in Mt. Pleasant,” Stark explained. “I went to James Van Allen Elementary School and my parents happened to live in Van Allen’s childhood home at one point.”

You might think all that stellar influence would spark a childhood passion for astronomy or maybe even physics. It didn’t.Chris Stark Chris Stark

“In spite of those coincidences, I didn’t grow up wanting to be an astronomer,” Stark said. “I didn’t stargaze at night, I wasn’t big into science fiction and space travel, none of that.”

But Stark eventually decided to become an astrophysicist, inspired by a college lecture that quite literally changed his life.

“The lecture was about exoplanets,” he recalled. “I remember thinking it was unbelievable that we have the ability to detect planets around stars outside our solar system. It was like a lightbulb went off! I knew exactly what I wanted to do with the rest of my life.”

Since then, Stark has spent nearly two decades unraveling the mysteries of distant planetary systems and developing tools to study them. In 2020, after years of exoplanet research and mission design, Stark became deputy integration test and commissioning project scientist for the James Webb Space Telescope (JWST)—the biggest, most powerful telescope ever launched into space.

“It’s incredibly exciting,” Stark said. “Webb was designed to look in the infrared at the faintest galaxies that one would possibly imagine—galaxies so distant that you’re essentially looking back in time to the first stars and the first galaxies that were formed. It’s an amazing opportunity.”

Falling in love with physics

For Stark, growing up in a small town in Iowa was worlds away from a career studying extrasolar planets and planning missions in space. As a kid, he had plenty of energy and liked to build things, encouraged by his industrious parents.

“My dad was a carpenter by trade for quite a while, and I can’t remember a time when he and my mom weren’t working on a project,” Stark explained. “It’s difficult to recall being around the house and not helping them with something, like re-roofing their house or laying a limestone retaining wall.”

In 1999 when Stark enrolled at the University of Northern Iowa, physics and astronomy were the furthest things from his mind. He was taking economics and marketing courses, looking ahead to a career in business. At the suggestion of his brother, who was also majoring in business, Stark signed up for a course called “The Physics of Everyday Life” to fulfill the physical sciences requirement for his degree. He never imagined what would happen next.

“The class was all about the physics behind everyday things like frisbees, CD players and cellphones. I was enthralled, and I just fell in love with physics,” he recalled. “I was learning about the world in a way that I never experienced before.”

Stark immediately changed his major to physics and never looked back. His very first undergraduate physics class—and later, that memorable lecture on exoplanets—set Stark’s course toward the stars. In fall 2004, he began his Ph.D. in physics at the University of Maryland.

“What really appealed to me was that Maryland’s physics department was so flexible with what their students researched, like biophysics and chaos theory and astronomy, which is what I ended up doing,” he said.

For Stark, UMD’s proximity to major research centers in the D.C. area, including NASA’s Goddard Space Flight Center, was ideal. 

“I could literally drive 10 minutes to NASA and chat with people there at lunch to see if they had a research project that they would want me to work on,” Stark recalled. “I found my first opportunity to research exoplanets at NASA by doing just that.”

Gamma rays and debris disks

After his first summer at NASA working on the Fermi Gamma-ray Space Telescope, Stark started working with Mark Kuchner, an expert on debris disks, the hazy dust clouds generated by asteroids and comets around other stars. At Kuchner’s suggestion, Stark applied for—and received—a NASA fellowship that funded three years of his Ph.D. research. For Stark, graduate school provided a world of opportunities, not just in research but in academics as well. 

“There’s some level of knowledge from the traditional academics that you’re taught in grad school that sticks with you for the rest of your career,” he explained. “I don’t know that a day goes by that some aspect of orbital mechanics or quantum mechanics doesn’t enter into my thoughts.” 

After earning his Ph.D. in 2010, Stark moved on to a postdoctoral position at the Carnegie Institution of Washington’s Department of Terrestrial Magnetism and spent three more years studying debris disks around distant stars. Three years later, he returned to NASA Goddard as a postdoc working with Aki Roberge, a research astrophysicist in the Exoplanets and Stellar Astrophysics Lab.

“I had been a theorist and an observational astronomer and when I started working with her, I said, ‘I’ve been working in this field for seven or eight years now I really want to get into mission design work,’” Stark explained. “And she said, ‘Have I got a project for you!’”

At the time, Roberge was studying a future telescope concept that would detect and image exoplanets. To determine what kind of telescope and other instruments would be needed, she had to develop a tool that could predict how many exoplanets the mission might discover. 

“We talked through how we would develop this tool and it turned out that everything I needed to do that project, I had the pieces already,” Stark recalled. “Forty-eight hours later, after reading through published papers and a lot of coding, I came back to her with a functioning skeletal structure of how this would work, and I think it hit both of us that we were onto something big.”

On a mission: the James Webb Space Telescope and Beyond

Together, Stark, Roberge and their colleagues developed a mission optimization tool that’s still being used by NASA today and Stark moved full steam into mission design. By 2015, he’d been hired as an associate scientist at the Space Telescope Science Institute in Baltimore, where he helped guide the design of future space telescopes and worked on the JWST, a huge NASA project that was still years away from launch.

“I was part of the team that prepared to align the mirrors of JWST after launch,” he explained. “Those golden hexagons, they all have to be aligned to within a fraction of a micron to work like one large mirror. The alignment is an amazing process, to be able to move around and shape a mirror segment more than a meter in size with such precision.”

Stark returned to NASA in 2020, taking on a new role as deputy integration test and commissioning project scientist for JWST, which launched in December 2021 and is now orbiting the sun on its journey of discovery.

“On a day-to-day basis, we’re tracking the performance of the telescope and instruments, and making sure that all the information we need is available to understand how the decisions we make impact science as we go,” Stark explained. “Working on this mission is thrilling, it’s stressful. More than anything, it’s humbling. It takes thousands of talented people to put something like this together.”

Stark is all about putting things together, and not just space missions. After years of doing construction projects with his parents as a kid, he still has a passion for building things at home in his spare time. No project is too big or too complicated.

“At this point, it’s an obsession. Anything that I can build is fair game. Honestly, that may be why I ended up in the position I’m in at NASA,” he mused. “I think there’s an aspect of designing future space missions that helps satisfy my need to build.”

From Stark’s Ph.D. studies to his current work on the Webb, every research project and every NASA mission have brought him closer to the dream he’s had since his very first day at UMD.

“My goal is to help launch a mission that has the chance of finding another planet that looks like Earth, and maybe even has biosignature gases that could be indicative of simple life,” Stark explained.

Stark believes that mission will soon be a reality. And he can’t wait to be part of it.

“We have so many exciting missions coming up that get at fundamental questions that humans have been asking themselves for millennia. We’re going to fundamentally transform our understanding of our place in the universe,” he said. “The next few decades of astronomy is really going to knock your socks off.”

Written by Leslie Miller

Thomas Ferbel, 1937- 2022

Thomas Ferbel, a UMD visiting professor since 2013, died at his home on Saturday, March 12. He was 84.

Ferbel was born in 1937 in Radom, Poland. During the tumult of World War II, he and his family endured exile in a Russian gulag and later, a camp for displaced persons in Stuttgart. Eventually, Ferbel arrived in New York and received a B.A. in Chemistry from Queens College, CUNY, and his and Ph.D. in Physics from Yale University (where his favorite professor was Bob Gluckstern, later the chancellor of this campus and a professor of physics).Thomas FerbelThomas Ferbel

After a postdoctoral appointment at Yale, Ferbel accepted a faculty position at the University of Rochester in 1965.  While there, he received an Alfred P. Sloan Fellowship, a John S. Guggenheim Fellowship and an Alexander von Humboldt Prize.

He was elected a Fellow of the American Physical Society in 1984, and served as the U.S. program manager for the Large Hadron Collider from 2004-08.

In 2020, Ferbel described both his early years and his life as a physicist as part of the American Institute of Physics Oral History project. The transcript is available here: https://www.aip.org/history-programs/niels-bohr-library/oral-histories/46304

Bennewitz Named Finalist for Hertz Fellowship

Elizabeth Bennewitz, a first-year physics graduate student at JQI and QuICS, has been named a finalist for a 2022 Hertz Fellowship. Out of more than 650 applicants, Bennewitz is one of 45 finalists with a chance of receiving up to $250,000 in support from the Fannie and John Hertz Foundation.

The fellowships provide up to five years of funding for recipients pursuing a Ph.D. The foundation seeks(link is external) individuals who intend to tackle “major, near-term problems facing society.”Elizabeth Bennewitz (credit:  Dan Spencer)Elizabeth Bennewitz (credit: Dan Spencer)

“This whole group of finalists have accomplished so much, and I’m very humbled to be among other people starting their Ph.D.s who are also pursuing big problems in science,” says Bennewitz. “I'm very honored to be part of this finalist group.”

Bennewitz is working with JQI and QuICS Fellow Alexey Gorshkov and is interested in researching large collections of interacting quantum particles—what scientists call many-body quantum systems. These systems are important to understanding cutting-edge physics and quantum computer technologies and can also be the basis of simulations that could provide insights into complex problems in physics, material science and chemistry.

“During my PhD, I want to develop tools and techniques that help harness the computational power of quantum devices in order to simulate these large quantum many-body systems,” Bennewitz says. “I’m excited to be pursuing this research at Maryland because of its commitment to quantum information and quantum computing research as well as its rich collaboration between theorists and experimentalists.”

Bennewitz is just at the beginning of her graduate student career, but she has already started investigating how quantum simulators might be used to understand the interactions of the particles that are responsible for holding the nuclei of atoms together.

“I'm very happy for Elizabeth, and I'm honored and excited that she chose to work with my group,” Gorshkov says.

An announcement of the winning fellows is expected to be made in May.

“I'm very thankful for all the opportunities I had before I got here,” Bennewitz says. “I would not be where I am today without the support and guidance I received from my professors and peers at Bowdoin College and Perimeter.”

Original story by Bailey Bedford: https://jqi.umd.edu/news/jqi-graduate-student-finalist-hertz-fellowship

Kollár Awarded Sloan Research Fellowship

Assistant Professor Alicia Kollár has been awarded a prestigious 2022 Sloan Research Fellowship. This award is given to early career researchers by the Alfred P. Sloan Foundation to recognize distinguished performance and the potential to make substantial contributions to their field. Each fellowship provides $75,000 to support the fellow’s research over two years.

Kollár will use the fellowship to support her research into creating new synthetic materials that are designed using quantum physics and applied mathematics. These synthetic materials can reveal physics that is difficult or impossible to observe in traditional materials.

“What really excites me about this award is to see support for the more interdisciplinary side of my research,” Kollár says. “My original background is in quantum physics and that's been where my grant support has come from so far, but this Sloan award is focused on looking at questions at the intersection of math and physics.”Alicia Kollár Alicia Kollár

This line of Kollár’s research uses mathematical tools based on the field of graph theory—the study of relationships between objects (in terms of a “graph” made of “vertices” that are connected by “edges”). Researchers use the tools to produce stripped down descriptions of materials in terms of just nodes and their connections—like if there is a connection where electrons can hop between specific points in a material. These descriptions don’t care about the exact distance between atoms or molecules or their precise orientation relative to each other but only about what connections exist between points. This approach is useful for identifying overarching features of different types of materials and is especially helpful in sorting out which material properties are derived from the basic connections being investigated, as opposed to those related to the quirks of a material’s particular components.

This mathematical perspective allows researchers, like Kollár, to design abstract connections that should produce unique properties, but it isn’t easy to then translate the idea on a page into a material that has the exact desired connections. Going from pure math to a real material is much harder than the reverse process of stripping details away from a well-studied material; to do so requires the exhaustive work of recognizing and juggling all the idiosyncrasies of real chemistry. The details of all the possible choices of atoms and how they interact and arrange themselves makes matching the elegant mathematical design to a physical material prohibitively challenging.

So instead Kollár has focused on synthetic materials made of circuits of resonators and superconducting qubits that house traveling microwaves. These circuits easily recreate the flexible connections of graph-theoretic descriptions and can let the complex physics play out, revealing features that current simulations can’t calculate. Essentially, Kollár can custom design the desired connections in a synthetic material and see if the results are interesting instead of going through the hassle of searching for a chemical structure that naturally has the connections every time she wants to do a new experiment. She has even been able to create connections that simulate a negatively curved space—a space impossible to create in the lab because they have “more space” than our normal space.

The insights from these synthetic materials have the potential to reveal new material behaviors and to give researchers a better understanding of how to best use graph-theoretic techniques.

Besides making these synthetic materials she is also working to push the mathematical side of this approach, including identifying new mathematical rules that govern one dimensional graphs that might provide insights into codes used in quantum computing.

 “This Sloan Fellowship will give my group the opportunity to really dig in to optimizing how synthetic materials are made in order to make them as versatile a tool as possible,” Kollár says.

The Sloan fellowships are awarded to untenured teaching faculty who work in the fields of chemistry, computer science, Earth system science, economics, mathematics, neuroscience, physics, or a related field. Candidates are nominated by their colleagues, and then fellows are selected by an independent committee of researchers in the relevant field based on the candidates’ “independent research accomplishments, creativity, and potential to become leaders in the scientific community through their contributions to their field,” according to the Sloan website. Other UMD winners this year are Lei Chen of mathematics and Pratyush Tiwary of chemistry/biochemisty and IPST. 

“Today’s Sloan Research Fellows represent the scientific leaders of tomorrow,” says Adam F. Falk, president of the Alfred P. Sloan Foundation. “As formidable young scholars, they are already shaping the research agenda within their respective fields—and their trailblazing won’t end here.”

 

Original story by Bailey Bedford: https://jqi.umd.edu/news/jqi-fellow-kollar-awarded-sloan-research-fellowship