Stardust Interstellar Preliminary Examination IV: Scanning transmission X‐ray microscopy analyses of impact features in the Stardust Interstellar Dust Collector

Abstract We report the quantitative characterization by synchrotron soft X‐ray spectroscopy of 31 potential impact features in the aerogel capture medium of the Stardust Interstellar Dust Collector. Samples were analyzed in aerogel by acquiring high spatial resolution maps and high energy‐resolution spectra of major rock‐forming elements Mg, Al, Si, Fe, and others. We developed diagnostic screening tests to reject spacecraft secondary ejecta …