Sept. 21, 2000
Vol. 20 No. 1

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    Geophysical Sciences scholars mentor high school student in meteorite study

    By Steve Koppes
    News Office

    Rebecca Elsenheimer of Lisle, Ill., graduated this year from the Illinois Mathematics and Science Academy with hundreds of hours of research experience in a University meteorite laboratory to her credit. The research experience helped Elsenheimer earn an award from the Russian Academy of Sciences, and co-authorship of a paper that one of her mentors delivered last month at the 63rd Annual Meteoritical Society Meeting in Chicago.

    The Meteoritical Society paper, titled “First Rock from the Sun,” describes what appears to be a sample of the first solids that condensed out of the primordial cloud of gas and dust from which the sun and planets formed approximately 4.5 billion years ago.

    The two earliest minerals to condense from the cooling gas were corundum, a pure aluminum oxide closely related to sapphire, and hibonite, a calcium aluminum oxide, according to calculations performed by Lawrence Grossman, Professor in Geophysical Sciences, and his research team in the department.

    Elsenheimer worked in Grossman’s laboratory for six hours nearly every Wednesday during her junior and senior years through the IMSA mentorship program. The program matches approximately 150 IMSA students annually with mentors in Chicago area universities, medical centers, museums and corporations.
    Rebecca Elsenheimer and one of her mentors, Steven Simon, Senior Research Associate in Geophysical Sciences, look over some of the meteorite samples they worked with for their study, which later became “First Rock from the Sun,” a paper that was presented at the Meteoritical Society Meeting last month.

    Grossman and Steven Simon, Senior Research Associate in Geophysical Sciences, listed Elsenheimer as a co-author of their Meteoritical Society paper because of her important contribution to the project. Grossman and Simon have mentored approximately 10 IMSA students since the early 1990s.

    “We didn’t know what Rebecca was going to find,” Simon said. “She took apart the meteorite and recovered these minerals that formed very early in the history of the solar system.”

    Grossman said, “IMSA students are all very bright. Rebecca was a self-starter. She picked up the technique of scanning electron microscopy from Steve, and away she went.”

    Grossman and Simon’s tutelage played a key role in Elsenheimer’s success, along with her high level of talent and commitment, said Peggy Connolly, IMSA mentorship program coordinator. “To volunteer to work with a high school student for two years and to train her for this caliber of research is phenomenal,” Connolly said. “None of this could have happened without their willingness to take a chance on a young person.”

    Supporting the research of Grossman and Simon, the National Aeronautics and Space Administration helps fund their studies of the Murchison meteorite from Australia. The two scientists are searching for clues to conditions in the early solar system. Elsenheimer’s task was to help them find mineral inclusions contained in the meteorite.

    First, she repeatedly froze and thawed a sample of the meteorite until it broke apart. Then she examined each tiny particle under an optical microscope, selecting the most interesting inclusions for further analysis. Many of the particles were barely visible to the naked eye, measuring no more than the width of a human hair.

    Grossman and Simon took the samples that passed the first screening, cut them into microscopically thin sections and mounted them on glass slides. Then Elsenheimer used a scanning electron microscope and an X-ray analyzer attachment to photograph the inclusions and identify the minerals they contained.

    One of the inclusions turned out to contain corundum, perhaps the most primitive mineral Grossman’s team has ever encountered in a meteorite. The team’s calculations indicate that corundum would have condensed early in the history of the solar system at a temperature of approximately 2,730 degrees Fahrenheit. Hibonite, a related mineral, would follow close behind at approximately 2,650 degrees.

    Elsenheimer drafted a paper based on her Chicago research and translated it into Russian. Last May, Elsenheimer, who speaks Russian, was the only U.S. student to deliver her paper in Russian at the Sakharov Readings, a research and ethics conference held annually in St. Petersburg in honor of the late physicist and Nobel Peace laureate Andrei Sakharov.

    The day before her presentation, Elsenheimer had visited the Hermitage, a renowned art museum in St. Petersburg. There she saw a portrait of Catherine the Great with the Russian crown next to her that contained a gem related to her research.

    “On top of the crown was this very large gem, a spinel, which is one of the minerals in the inclusions we looked at. So I was able to tell the audience that you can find spinel in some of the meteorites we studied,” Elsenheimer said.

    More than 200 high school students from five countries had been invited to present their work at the conference, including five from IMSA. Elsenheimer was the one who received top honors for her presentation as determined by a panel of judges from the Russian Academy of Sciences and the A.F. Ioffe Physics Institute and Polytechnic High School in St. Petersburg.

    A National Merit Scholar, Elsenheimer was accepted by the University, the Massachusetts Institute of Technology and Rice University. She has entered Rice University in Houston, Texas, as a freshman astrophysics major.