Matthew Marcus: Soft x-ray spectromicroscopy in extraterrestrial materials

Extraterrestrial materials such as meteorites and interplanetary dust particles are often very complex and non-uniform, with diverse species within a small sample. In some cases, especially for the products of sample-return missions, the available samples are small and precious. X-ray micro- and nano-spectroscopy are ideal complements to other methods such as TEM and nano-SIMS. In this talk, I will review several examples from the literature showing how X-ray spectromicroscopy has been used to study extraterrestrial materials and infer their histories of formation and alteration. I will also review some experimental techniques, especially STXM.

References:

1. Sandford, Scott A., et al. “Organics captured from comet 81P/Wild 2 by the Stardust spacecraft.” Science 314, no. 5806 (2006): 1720-1724.
2. Lo, Yuan Hung, et al. “Multimodal x-ray and electron microscopy of the Allende meteorite.” Science advances 5, no. 9 (2019): eaax3009.
3. Van Aken, P. A., and B. Liebscher. “Quantification of ferrous/ferric ratios in minerals: new evaluation schemes of Fe L 23 electron energy-loss near-edge spectra.” Physics and Chemistry of Minerals 29, no. 3 (2002): 188-200.