Astromat

Bidirectional relative reflectance spectra of OSIRIS-REx returned sample OREX-800029-0 (200 mg of Bennu aggregate, bulk material from the TAGSAM head, delivered in an Eagle stainless steel container) were acquired using two spectrometers: an ASD LabSpec 4 hi-res (350-2500 nm) and an Ocean Optics Maya2000 Pro (250-500 nm). Measurements were conducted under ambient air conditions (temperature approximately 24 degrees C, relative humidity approximately 7-9%) in January 2024. The sample was poured unsorted into an aluminum cup (12.5 mm wide, 3.25 mm deep, bevelled). For the ASD dataset, 47 spectra were acquired across 10 sample spots (Spots A-N) at a range of viewing geometries (incidence angles 0-70 degrees, emission angles 0-70 degrees, phase angles 20-130 degrees) using a 150W halogen light source operated at 70W DC. Integration times and spot sizes varied by geometry. Spectra were calibrated against a Fluorilon reference standard and corrected for Fluorilon absorption features; 1000 nm and 1800 nm detector-splice breaks were removed. For the Maya2000 Pro dataset, 5 spectra were acquired at 5 spots at normal incidence and emission (i=0, e=0) using a 30W UV light source with a bifurcated fiber optic. All spectra are reported as relative reflectance. The sample was neither heated nor vacuum-exposed prior to measurement.