February 4, 2000

Colloquium Topic: Extraterrestrial Water

Crystals of halite and sylvite within the Monohans (1998) and Zag H5 chondrites contain aqueous fluid inclusions. The fluids are dominantly NaC1-KC1 brines, but also contain divalent cations such as Fe, Mg or Ca. Two possible origins for the brines are (i) indigenous fluids flowing within the asteroid, and (ii) exogenous fluids delivered into the asteroid surface from a salt containing icy object. Since both of these meteorites are asteroid regolith samples, these results have significant implications for the surface mineralogy of the regoliths of the NEAR and Muses-C mission target asteroids.

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Colloquium Speaker: Michael Zolensky

Dr. Michael Zolensky received his B.S. in Geology from the New Mexico Institute of Mining and Technology in 1977 and his Ph.D. in Geochemistry and Mineralogy from the Pennsylvania State University in 1983. He joined NASA Johnson Space Center as a NRC Postdoctoral Fellow and currently he is a space scientist. Dr. Zolensky has led or participated in many successful meteorite recovery expeditions and developed techniques for characterization of meteoroid and space debris features on spacecraft. He led the effort to characterize the impact record of the Long Duration Exposure Facility satellite, developed techniques for the analysis of microparticles and has characterized the chemical weathering record of asteroids. He has published more than 300 publications. Dr. Zolensky's current research focuses on solar system materials and processes. He is a co-investigator of STARDUST Discovery Mission, an Associate Curator for Interplanetary Dust and hardware returned from space and he chairs the Cosmic Dust Working Group.