Bidiectional VNIR reflectance spectrum of assembled fragments up to 5 mm in size of a mottled rock sample OREX-800073-0 of asteroid Bennu was measured using RELAB Bidirectional Spectrometer at the standard viewing geometry of 30-degree incidence and 0-degree emergence angles.

20241031_VNMIR_BROWN_OREX-800073-0_1_VNMIRSpectralPoint_1.csv

20241031_VNMIR_BROWN_OREX-800073-0_1_VNMIRSpectralPoint_1.yaml

20241031_VNMIR_BROWN_OREX-800073-0_1_analysisLocation_1.jpg

20241031_VNMIR_BROWN_OREX-800073-0_1_analysisLocation_1.yaml

20241031_VNMIR_BROWN_OREX-800073-0_1_plot_1.png

20241031_VNMIR_BROWN_OREX-800073-0_1_plot_1.yaml

This material is supported by NASA PSEF grant.

Visible, near-, and mid-infrared spectroscopy

Custom bi-directional

Brown University

Standard deviation in reflectance over entire dwell time at that wavelength

Bidirectional visible and near-infrared reflectance spectrum of asteroid Bennu sample OREX-800073-0. The sample was loaded in a 9-mm black Teflon dish with a 7.2-mm field of view. RELAB sample ID is BN-REM-008, and spectral file name is C1BN08. Wavelength range was 300-2600 nm, and the data were collected at every 5 nm. Reflectance is measured one wavelength channel at a time relative to Spectralon from Labsphere while both Spectralon and each sample were spun at a speed of 1.5 seconds per rotation during the measurements. Effects of Spectralon absorption features were corrected. Each measurement at each wavelength consists of a single scan with a dwell time that varies as a function of the albedo of the material at each wavelength. Minimum dwell time is 4.5 seconds, and the maximum dwell time is 34.5 seconds. Connection point between detectors is between 860–880 nm. Overlap region is averaged. A quartz depolarizer was used over 300-420 nm and 2050-2500 nm, and a calcite depolarizer was used over the wavelength range of 400-2070 nm. Albedo was adjusted to the visible range.

The analyzed spot is indicated with a red circle of about 7.2 mm in diameter of the sample mounted on a 9-mm diameter black Teflon dish.

A plot of bidirectional VNIR reflectance spectrum of OREX-800073-0 fragmented sample.

Astromat

Bidirectional visible to near-infrared reflectance spectrum of fragments of mottled rock OREX-800073-0.

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