Lithological diversity among howardites and its implications for the HED parent body

• Applicant: Dr. Andrea Patzer-Wilson
• Subject Area: Mineralogy, Petrology and Geochemistry
• Term: from 2010 to 2012
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 181450780

Howardites belong to the most abundant group of differentiated meteorites, the howardite-eucrite-diogenite (HED) suite. These achondrites are believed to originate from 4 Vesta, the second largest body in the main asteroid belt between Mars and Jupiter. Howardites are surface rocks, i.e., fragmental breccias, comprising the most complete sample set of lithologies existing on Vesta. The ongoing NASA mission to the asteroid belt (Dawn) is set to ultimately prove the genetic link between HEDs and Vesta. Remote sensing exploration of the asteroid’s surface will return data that can potentially be matched with the chemical features of howardites. In this context, it is crucial to know the individual components and categories of this meteorite subclass. So far, much focus has been placed on howardite bulk chemistry, and only few samples have been described in detail. Deficits exist as far as an extensive petrologic survey and the search for possible systematic compositional variations are concerned. It is the goal of this project to give a comprehensive overview of lithic ingredients in howardites and their implications for the formation of HEDs, i. e., Vesta’s petrogenesis. In addition, learning about the evolutionary history of Vesta will contribute to understanding the processes and evolution of small planetesimals in the early Solar System.

• DFG Programme: Research Fellowships
• International Connection: USA
• Host: Professor Harry Y. McSween, Ph.D.