June 7, 2001
Vol. 20 No. 18

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    Astronomical Union names asteroids after University scientists

    By Steve Koppes
    News Office

    Asteroids have been named for the Egyptian King Amenhotep, rock musician Frank Zappa and an entire pantheon of Greek and Roman deities. Now, four Chicago professors have received the distinction.

    Last fall, the Small Bodies Names Committee of the International Astronomical Union approved a proposal to name asteroids after Robert Clayton, the Enrico Fermi Distinguished Service Professor in Chemistry and Geophysical Sciences; Lawrence Grossman, Professor in Geophysical Sciences; Edward Anders, the Horace Horton Professor Emeritus in Chemistry; and the late Harold Urey, the Martin Ryerson Distinguished Service Professor in Chemistry. But word of the honor only recently reached Clayton, Grossman and Anders.

    “Having argued for the asteroidal origin of meteorites in the 1950s and 1960s, when this was a very controversial idea, I am glad that my friendly feelings toward asteroids are being reciprocated in this manner,” Anders said.

    More than 8,000 asteroids have been named to date. Asteroids receive a provisional designation––such as 1989 UL5 in the case of asteroid Urey––after being spotted by the same observer over two nights within a week. After scientists calculate an accurate orbit for the object, the discoverer chooses a name, which must be approved by the International Astronomical Union. The IAU is the only organization that has international authority to name astronomical bodies and features on them.

    The Chicago namesakes are known as 4564 Clayton, 4565 Grossman, 4716 Urey and 4815 Anders.

    Schelte “Bobby” Bus of the University of Hawaii’s Institute for Astronomy discovered all four asteroids. Bus discovered asteroids Clayton, Grossman and Anders while making observations from Siding Spring, Australia, in March 1981. He discovered asteroid Urey while working from Cerro Tololo, Chile, in October 1989.

    Bus, a prolific discoverer of asteroids, asked Tom Burbine and Tim McCoy, scientists at the Smithsonian Institution’s National Museum of Natural History, to help him name the space rocks after meteorite researchers.

    In the IAU publication that announced the new names, Burbine and McCoy cited Clayton for his pioneering use of oxygen isotopes, a chemical fingerprint, in understanding the processes that formed the planets and asteroids early in the history of the solar system. His work also established that material from other stars survived the harsh conditions that gave birth to the solar system, the citation said.

    Clayton also is being honored in a special symposium organized by the Geophysical Sciences Department Thursday, June 7, and Friday, June 8. Presenting talks highlighting Clayton’s scientific career will be former students, postdoctoral associates and close colleagues.

    Grossman was cited for his pioneering study of calcium-aluminum inclusions found in meteorites. “He was among the first to propose that these minerals condensed from gases in the early solar system,” the citation said.

    Urey, who served on the Chicago faculty from 1945 to 1958, was cited for receiving the 1934 Nobel Prize in chemistry for his discovery of deuterium, a heavy form of hydrogen, and for being one of the founders of modern planetary science. “His classic book The Planets (1952) discussed planetary objects and meteorites in the context of chemical and physical relationships,” his citation said.

    Anders was cited for his “many seminal contributions to the field of meteorites.” He was particularly cited for providing early evidence that meteorites came from asteroids rather than a fragmented planet, and that organic matter in meteorites are of non-biological origin.

    Mars also has two features named for another Chicago scholar. An impact crater near the Martian equator that measures 59 miles in diameter was named last August for the late astronomer and University alumnus Carl Sagan. Also, the Mars Pathfinder landing site was officially named the Carl Sagan Memorial Station in 1997.