Séminaire - Space weathering of minerals – experimental simulation and natural observations on Hayabusa dust particles - Falko Langenhorst

IMPMC - Sorbonne Université - 4 place Jussieu, 75005 Paris, tour 23, 4^e étage, couloir 22-23, salle 401

Lundi 14 mai 2018 à 10 h 30

Falko Langenhorst - Jena - Germany

Abstract

The Space weathering, i.e. surface damage of minerals due to exposure to solar wind and micrometeorite impacts, alters the reflectance spectra of airless Solar System bodies, complicating our ability to determine properties from remote observations. Our understanding of space weathering was, so far, grounded in studies of lunar regolith grains. However, samples of regolith recently returned from asteroid Itokawa by the Hayabusa mission, combined with laser irradiation experiments provide new insight into space weathering. This combined approach reveals that the thin (< 100 nm) space-weathered rims in silicate minerals can be compositionally and structurally heterogeneous down to the nanometer scale, reflecting phase transformations, plastic and brittle deformation, decomposition and redox reactions. The talk will briefly introduce into the exciting Hayabusa mission and experimental simulation techniques, and illustrate the different space-weathering phenomena based on TEM observations.