Tagish Lake meteorite specimen, 10 cm in its longest dimension.  Credit: Michael Holly, Creative Services, University of Alberta.

New research from Carnegie’s Department of Terrestrial Magnetism and Geophysical Laboratory, published in the June 10 issue of Science, shows that most of the differences in complex organic materials seen among carbonaceous chondrite meteorites can be found within a single meteoroid and that the variations are the result of hydrothermal activity in a still larger parent body, likely an asteroid, within the first few million years of Solar System history.

The research team—led by Christopher Herd of the University of Alberta, Canada, and including Carnegie’s Conel Alexander, Larry Nittler, Frank Gyngard, George Cody, Marilyn Fogel, and Yoko Kebukawa—studied four meteorite specimens from the shower of stones, produced by the breakup of a meteoroid as it entered the atmosphere, that fell on Tagish Lake in northern Canada in January 2000.  Examination of the specimens’ inorganic components indicated that they had experienced large differences in the extent of hydrothermal alteration, prompting an in-depth examination of their organic material. The team demonstrated that the insoluble organic matter found in the samples has properties that span nearly the entire range found in all carbonaceous chondrites and that those properties correlate with other measures of the extent of parent body alteration. Their finding confirms that the diversity of this organic material is due to processing of a common precursor material in the asteroidal parent bodies.

“Taken together these results indicate that the chemical and thermal processing common to the Tagish Lake meteorites likely occurred when the samples were part of a larger parent body that was created from the same raw materials that formed our Solar System,” said DTM research scientist Larry Nittler. “These samples can also provide important clues to the source of organic material, and life, on Earth.”

Please click here for the Carnegie Press Release.