Field Museum meteorite research presented at the MetSoc Meeting in Edmonton, Alberta

Tue, 08/13/2013 - 10:19 -- pheck

Cryogenic meteorite storage of Tagish Lake with meteoriticists Chris Herd, Ellen Harju, Philipp Heck, Alan Rubin. Photo credit: Denton Ebel.

Philipp Heck, James Holstein, and graduate student Levke Koeoep attended the Annual Meeting of the Meteoritical Society in Edmonton, Alberta earlier this month. Jim and Levke presented their research projects during the poster session in the University of Alberta’s Art Gallery. Levke showed her latest study on her rich harvest of hibonite and spinel minerals from the Murchison meteorite. These minerals are among the first solids that formed in the solar system and their study provides information on the environmental conditions in the early solar system.
Jim’s work on survival of meteorites on the sea floor will be helpful in classifying extraterrestrial minerals found in marine sediments and in determining their sources. His systematic study of a suite of ordinary chondrite meteorites is determining which minerals best survive weathering on the sea-floor and is characterizing these.
Philipp presented his study of presolar minerals in the Sutter’s Mill meteorite. Philipp is co-author on the first study of that meteorite, which was published in the journal Science in December last year, that showed that some parts of the Sutter’s Mill parent asteroid were very wet whereas other parts of the same asteroid never saw any water. At the meeting, Philipp presented how he and his colleagues from Washington University in St. Louis and the University of Chicago analyzed the abundance and compositions of presolar minerals in Sutter’s Mill to infer how water and heat affected those minerals. In addition, the team determined the types of parent stars of the eight presolar grains that have been found so far. Presolar grains are the oldest solid samples available to any lab and are essentially time capsules from the time before the solar system formed 4.6 billion years ago. The Field Museum has one of the largest presolar grain collections worldwide. Terry Boudreaux and other meteorite aficianados take note: While in Edmonton, Philipp also visited the cryogenic meteorite storage facility at the University of Alberta (see photo). There, the unique carbonaceous chondrite meteorite Tagish Lake is stored at -20 degrees C (-4 degrees F). It must be handled in a nitrogen glove box to minimize contamination. Tagish Lake fell onto the frozen lake of that name in 2000 and has been kept frozen ever since in order to prevent volatiles and (abiotic) organics to evaporate (most other meteorites lost their volatiles after they hit Earth and thawed).