Bidiectional VNIR reflectance spectrum of round and flat faces of a large particle of an aggregate sample OREX-803124-0 of asteroid Bennu were measured using RELAB Bidirectional Spectrometer at the standard viewing geometry of 30-degree incidence and 0-degree emergence angles.

20240412_VNMIR_BROWN_OREX-803124-0_1_VNMIRSpectralPoint_1.csv

20240412_VNMIR_BROWN_OREX-803124-0_1_VNMIRSpectralPoint_1.yaml

20240412_VNMIR_BROWN_OREX-803124-0_1_analysisLocation_1.jpg

20240412_VNMIR_BROWN_OREX-803124-0_1_analysisLocation_1.yaml

20240412_VNMIR_BROWN_OREX-803124-0_1_plot_1.png

20240412_VNMIR_BROWN_OREX-803124-0_1_plot_1.yaml

This material is supported by NASA PSEF grant.

Visible, near-, and mid-infrared spectroscopy

Thermo/Nicolet Nexus 870 FTIR

Brown University

Standard deviation in reflectance over entire dwell time at that wavelength

Bidirectional visible and near-infrared reflectance spectrum of a round face of a large particle of OREX-803124-0 aggregate sample. The sample was loaded in a 2.5-mm black Teflon dish.  RELAB sample ID is BN-REM-003, and spectral file name is CABN03. Wavelength range was 320-2550 nm, and the data were collected at every 10 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 320-420 nm and 2050-2550 nm, and a calcite depolarizer was used over the wavelength range of 400-2070 nm. Albedo was adjusted to the visible range.

The analyzed face is indicated with a red circle of about 0.8 mm in diameter on a round face of a large particle in the center of a 2.5-mm diameter black Teflon dish.

A plot of bidirectional VNIR reflectance spectrum of a round face of a large particle of OREX-803124-0 aggregate.  Smooth bumps in the spectrum in the region beyond 1 micron in wavelength are likely artifacts.

Astromat

Bidirectional visible to near-infrared reflectance spectra of a large particle of asteroid Bennu aggregate OREX-803124-0.

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