MICRO-FT-IR HYPERSPECTRAL SURFACE CHARACTERIZATION OF INDIVIDUAL RYUGU GRAINS: MATRIX COMPOSITION AND SPACE WEATHERING EFFECTS

Sample-return space missions allow us to investigate materials from outer space with state-of-the-art laboratory techniques [1]. Constraining the material mineralogical and physical properties enables us to better understand their parent bodies’ history and our Solar System [2, 3]. JAXA’s Hayabusa2 mission [4] acquired spectroscopic data and samples from primitive body C-type asteroid Ryugu. Samples originate from two collect sites (A: surface, C: presumably sub-surface). Here, we look for spectral differences across the surface of individual grains to assess mineralogical differences and identify possible effects of space weathering (i.e., an ensemble of processes affecting the surface of airless bodies, which alters their surface spectral, elemental, and morphological properties [5]). Our samples comprised three mm-sized grains (two samples from site A and one from site C): A0226-1, A0226-2, and C0242 [6]. Grain A0226-2 separated from A0226-1. We characterized the samples’ surface via micro-FT-IR hyperspectral imaging in the mid-IR (2-16 μm) to probe the spatial distribution of phyllosilicates, anhydrous phases, and organic matter.