SAN FRANCISCO - Leading scientists will report what they have learned about how mixtures of lifeless chemicals were transformed into living organisms at a special symposium on the origins of life at the 219th national meeting of the American Chemical Society, the world's largest scientific society. Several papers report new findings from experiments that simulate the early solar system. Other studies shed light on the origins of life on Earth and the possibilities of finding remnants of life on Mars, Europa and other extraterrestrial bodies. Selected papers are described below.
Asymmetry could signal start of life: Homochirality, the exclusive "one-handedness" of life molecules, has been recognized since the time of Pasteur as a determining characteristic of life processes. The excess of one-handedness recently seen in organic compounds taken from meteorites indicates that such asymmetry could precede the origin of life. An Arizona State University scientist will discuss these and newer findings. A scientist at the University of Bremen, Germany, will report on the development of a gas-chromotography-based chiral probe to be used in an international space mission to the comet Wirtanen. (S. Pizzarello, Arizona State University, Tempe, Ariz.; GEOC 27; Monday, March 27, 9:45 a.m., Hilton, Franciscan B, Ballroom Level. See page 114 in the final program. W. H. P. Thiemann, University of Bremen, Germany; GEOC 55, Tuesday, March 28, 8:30 a.m., Hilton, Franciscan B, Ballroom Level. See page 115 in the final program.)
Researchers simulate early solar system chemistry: Scientists report that 1,4-naphthaquinone was formed during lab experiments that simulated the chemistry of the early solar system. The compound is similar in structure to the K vitamins, whose functions range from helping blood clot in people to transporting electrons in anaerobic bacteria. Dense clouds, believed to be the source of the icy dust from which comets and meteorites formed, may have seeded the early Earth with organic material necessary for life. The researchers used an icy mixture of water and napthalene to simulate this environment. When the mixture was exposed to ultraviolet light, naphthalene oxides and naphthaquinones formed. (J. P. Dworkin, SETI Institute/NASA Amese Research Center, Moffett Field, Calif.; GEOC 48, Monday, March 27, 4:10 p.m., Hilton, Franciscan B, Ballroom Level. See page 115 in the final program.)
Superhot systems could stimulate the start of life: Beneath the surface of Mars and the ice-covered oceans of Europa (Jupiter's moon) may be hydrothermal systems like the hot springs, volcanoes and undersea vents on Earth. Researchers will present the results of their ongoing investigation of organic synthesis from carbon dioxide and hydrogen under hydrothermal conditions. In some experiments, the ingredients generated compounds that appear to be the ideal components for the start of life. (T. M. McCollom, Woods Hole Oceanographic Institute, Woods Hole, Mass.; GEOC 28, Monday, March 27, 10:15 a.m., Hilton, Franciscan B, Ballroom Level. See page 114 in the final program.)
Organisms preserved in permafrost could provide clues to the origin of life: The potential for subsurface permafrost on Mars makes the permafrost on Earth an important source of information regarding the preservation of living organisms and their remains. Astrobiologists at the Jet Propulsion Laboratory are using permafrost cores from the Kolyma lowland area of northeastern Siberia to study both the temperature history of the cores and the preservation of organisms in frozen environments. Stratigraphic dating methods indicate the cores may be as much as 3 million years old. The studies were conducted in collaboration with the Russian Academy of Sciences, Moscow Region. (K. L. F. Brinton, Astrobiology Research Elements, Pasadena, Calif.; GEOC 45, Monday, March 27, 3:10 p.m., Hilton, Franciscan B, Ballroom Level. See page 115 in the final program.)