Surface Thermophysical Properties determination of OSIRIS-REx target asteroid (101955) Bennu

Abstract

In this work, we investigate the thermophysical properties of OSIRIS-REx target asteroid (101955) Bennu (hereafter, Bennu), where thermal inertia plays an important role in understanding the nature of the asteroid's surface, and will definitely provide substantial information for the sampling return mission. Using a thermophysical model incorporating the recently updated 3D radar-derived shape model \citep{Nolan2013} and mid-infrared observations of Spitzer-PUI, Spitzer-IRAC, Herschel/PACS and ESO VLT/VISIR \citep{Muller2012,Emery2014}, we derive the surface thermophysical properties of Bennu. The asteroid has an effective diameter of $510_{-40}^{+6}$ m, a geometry albedo of $0.047_{-0.0011}^{+0.0083}$, a roughness fraction of $0.04_{-0.04}^{+0.26}$, and thermal inertia of $240_{-60}^{+440}\mathrm{J}{\mathrm{m}}^{-2}{\mathrm{s}}^{-0.5}{\mathrm{K}}^{-1}$ for a best-fit solution at 1$\sigma$ level. The best-estimate thermal inertia indicates that fine-grained regolith may cover a large area of Bennu's surface, with a grain size that may range from $1.3$ to $31$~mm, and our outcome further supports that Bennu would be a suitable target for the OSIRIS-REx mission to return samples from the asteroid to Earth.

10 pages, 7 figures, 5 tables, accepted to MNRAS

References in corpus (4)

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Cited by in corpus (8)

• OSIRIS-REx: Sample Return from Asteroid (101955) Bennu
• Unusual polarimetric properties of (101955) Bennu: similarities with F-class asteroids and cometary bodies
• New candidates for active asteroids: main-belt (145) Adeona, (704) Interamnia, (779) Nina, (1474) Beira, and near-Earth (162173) Ryugu
• Thermophysical characteristics of the large main-belt asteroid (349) Dembowska
• Surface thermophysical properties investigation of the potentially hazardous asteroid (99942) Apophis
• Deep operator neural network applied to efficient computation of asteroid surface temperature and the Yarkovsky effect
• Thermophysical Characteristics of OSIRIS-REx Target Asteroid (101955) Bennu
• Possible sublimation and dust activity on primitive NEAs: Example of (162173) Ryugu