The Big Picture, continued

 

Origins

In 1955, when our planet was not so young, Koerner was born in Cincinnati to a pair of musicians—his mom a pianist, his dad a singer. They lived in Canton, Ohio, until he was 10, then moved to Long Beach, California. Family lore has it that Koerner heard a violin concert at age three and declared right then he wanted to be a violinist. Soon he started lessons in violin and piano. Piano stuck with him. Koerner describes it as “one of a few things for which I’ve had a lot of passion.” (He has competed in the International Tchaikovsky Piano Competition and taken top prizes at many regional and national-level events, including the Music Teachers National Association, the Young Artist Competition and the Joanna Hodges International Piano Competition.)
    Science, of course, has been another prevailing passion. As a child, Koerner was fascinated by space travel and had a kids’ book on Sputnik. He also loved to read about dinosaurs. But his father, a professor at a local bible college, was a little worried about his son’s interest in such heretical ideas. So he gave him another book, H.M. Morris’s creationist manifesto, The Twilight of Evolution.
    “It was really horrible and hard to read,” Koerner recalls. “Its basic point was to say we couldn’t have evolved because it violates the second law of thermodynamics. Well, you know, I was eight. The second law of thermodynamics just didn’t grip me as a compelling argument.” Not to mention, he adds, that it’s just plain shoddy science.
    What did intrigue him were a new show on television called Star Trek, reports of NASA space missions he had clipped from the newspaper and the dazzling display of amateur telescopes he saw in the window of a store he passed on his way to school. “It turned out the owner’s daughter went to my school and played cello for the orchestra,” Koerner says. “And so I got to know her and this guy let me do my junior-high science-fair project with his 12-inch in the backyard. At that point I decided I wanted to be an astronomer.”
    Music, however, came more easily in high school than did calculus and physics, eclipsing astronomy as a priority. “I was winning piano competitions at that point,” he says. “There were just a lot more carrots.” But instead of going to a conservatory after graduation, Koerner enrolled in the bible college where his father taught. By then, he was considering a career in the ministry and there was the incentive of free tuition.
    He didn’t last a year there. Koerner says he dropped out for reasons of “intellectual discontent,” and took a “long detour” out of academics altogether. It was the early 1970s, when the Jesus Movement was attracting young people who were either turned off—or felt turned away—by mainstream churches. Koerner joined a religious group that was an offshoot of the then “counterestablishment” Calvary Chapel.
    Though rock music and “California surfer-hippie” defined the congregation’s lifestyle, the church was theologically very traditional. Koerner left home at 18, got married and had two children, earning a living as a piano accompanist to choral groups, giving music lessons and performing in the Long Beach Symphony.
    By his late twenties, though, he was having “big questions about the religion thing”—in particular the conflict between mainstream scientific views and his church’s teachings. Seeking answers, he enrolled at California State University-Long Beach as a geology major. As he learned more about the Earth’s ancient rock record, he quickly set aside the literal interpretation of the biblical Creation story. Koerner ultimately graduated with a degree in physics and minors in math and geology. By that point, he was divorced and wanted to stay near his two children, so he pursued graduate studies in the planetary-science program at Caltech. Because of his life experiences, Koerner says, he was particularly intrigued with “this interface between culture, science and religion. And not all of what they do [in the planetary science program] is about that. So I kicked and screamed to do a thesis in the area of solar-system origins.”
    His adviser, Anneila Sargent, was doing work on circumstellar disks, which were thought to be the incubators for new planets. “Well, this was fantastic,” Koerner says, “because this was basically watching it happen in the act.”

In 1993, Koerner (with Sargent and Steve Beckwith) was the first to demonstrate that a gas disk was in a stable orbit around a young star, named GM Aurigae, indicating that the disk could give rise to a new set of planets. He and Sargent went on to confirm these findings with the observation of dust and gas emissions around other similar-aged stars. He also detected larger grains of dust around a young star, ostensibly coagulating to form planets.
    Scientists believe that when a star forms at the core of a collapsing molecular cloud, some of the gas and dust that contributes to the star’s construction is left orbiting the star in a flattened disk. Planets then form—over tens of millions of years—by the gradual accumulation of smaller objects within that disk. Within the hot, inner regions of a disk, only rock and metals can condense. This helps explain why the planets closest to our Sun—Mercury, Venus, Earth and Mars —are rocky and comparatively small. Further out, ices can also condense and planets-in-the-making can pick up even more material in their long orbits, attracting and holding helium as they become increasingly massive. Thus, we get “gas giants” like Saturn and Jupiter.
    Koerner’s discovery of the disk around HR 4796 and its tell-tale hole supplied another missing link in the evolution of solar systems. In later observations, he and Penn graduate student Zahed Wahhaj (along with two scientists from the original research team, Dana Backman and Mike Werner) found hotter dust well inside this hole, similar to the “zodiacal dust” left over from planet construction billions of years ago in the asteroid belt of our own solar system. Koerner likes to point out that if you were standing on Alpha Centauri, what you would observe of our own solar system is this zodiacal dust. Therefore, he explains, the presence of such dust around other stars may indicate where planets have formed.
    Koerner was doing post-doctoral work in the Jet Propulsion Lab, which is run by Caltech for NASA, when he got called out to Penn a couple of years ago. “When they hired me,” he explains, “the idea was to expand into this area of origins of solar systems.” But the senior astrophysicist who was behind the expansion left and Koerner, now head of the physics and astronomy department’s Planetary Origins Research Group, remains the lone faculty member in his specialty. “But I still hold out hopes that” this will change, he says. “And, of course, I like Penn a lot.”