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Project Progress

Brownlee and Matrajt worked on a variety of projects related to the delivery of pre-biotic materials to the early Earth. Following earlier work on amino acids in Antarctic micrometeorites (Matrajt G., Pizzarello S., Taylor S., Brownlee D. (2004). Concentration and variability of the AIB amino acid in Polar micrometeorites: implications for the exogenous delivery of amino acids to the primitive Earth. Meteoritics & Planetary Sci. 39(11): 1849-1858.) they did a series of pulse heating experiments on porous analog materials and found that certain organic phases can survive strong heating during atmospheric entry. The survival of these phases is due to ablative cooling analogous to heat shields designed to protect entering spacecraft. This work is described in Matrajt G., Brownlee D., Sadilek M., Kruse L. (2006). Survival of organic phases in porous IDPs during atmospheric entry: a pulse-heating study. Meteoritics and Planetary Science 41(6): 903-911. Related work on small meteoritic particles that deliver organic material to Earth is described in Munoz-Caro G.M., Matrajt G., Dartois E., d’Hendecourt L., Deboffle D., Montagnac G., Chauvin N., Boukari C., Le Du C. (2005). Nature and evolution of carbonaceous matter in interplanetary dust particles (IDPs): Effects of irradiation and identification with a form of amorphous carbon. Accepted in Astronomy & Astrophys. and Matrajt G., Guan Y., Leshin L., Taylor S., Genge M., Joswiak D., Brownlee D. (2006). Oxygen isotope measurements of bulk unmelted Antarctic micrometeorites. Geochimica et Cosmochim. Acta. in press.

Most of the work in the last year was focused on the Stardust comet sample return mission. Over 30 comet particles have been worked on at the UW lab. So far this work has focused on particle recovery, electron microscopy and various methods used to study organics. To support this work a remarkable process was developed for making microtome sections (that preserve organic materials in a organic-free support matrix. This is described in Matrajt G., and Brownlee D.,(2006) Acrylic embedding of Stardust particles encased in aerogel, Meteoritical Planet. Sci. in press