2:15 PM - 2:30 PM
[PPS03-13] Initial description plan of Bennu samples in JAXA curation
Keywords:sample return, asteroid
Introduction: Materials from primitive asteroids record the evolutionary history of the early Solar System. Diversities of physical and chemical compositions in asteroids provide key constraints on planet formation, planet migration, and late accretion. Pristine samples from the Cb-type asteroid Ryugu and B-type asteroid Bennu provide great opportunities to challenge these topics. JAXA will receive 0.5 % of bulk Bennu samples from NASA this year based on a Memorandum of Understanding (MOU). We plan to conduct the twofold examinations on Bennu samples at the curation facility – the initial description within N2 clean chambers and the detailed description outside of N2 clean chambers. We then plan to publish the obtained data on the database, which can be used by members of the scientific communities to request the samples via the Announcement of Opportunity (AO). Also, we will develop the curation technique using the opportunity of Bennu sample curation, which can be applied to Phobos sample curation in the MMX (Martian Moons eXploration) mission [1–2]. Bennu samples provide a great opportunity to push the boundary of developing analyses conducted at the JAXA curation facility. This will establish the foundation to study Phobos sample returned from MMX mission in the future.
Initial description. We will observe the bulk and individual Bennu samples with visible and infrared spectrometers within the N2 clean chamber. Infrared reflectance spectra of the Bennu samples will be obtained using a μFT-IR (wavelength: 2.0–13 μm) and MicrOmega (wavelength: 0.99–3.7 μm). We will confirm whether the band depth of OH-band (2.7–3.0 μm) between Ryugu and Bennu samples is different, as observed by the remote-sensing [3]. Visible and near-infrared band spectra of the samples will also be obtained through a flat glass window using a suite of cameras; a digital microscope with six band filters (ul [388 nm], b [475 nm], v [551 nm], Na [588 nm], w [699 nm], and x [852 nm]) and visible–infrared cameras (OROCHI; center wavelengths: 390, 480, 550, 650, 730, 860, and 950 nm). These two cameras will contribute to finding exogenous grains likely be delivered from other asteroids, potentially included in the Bennu samples [4].
Detailed description. The observation within the N2 clean chamber has several limitations [5–6]. We plan to characterize the return samples outside the clean chambers to verify the accuracy of values obtained within the initial description (e.g., bulk density [5]) and provide further information (e.g., thermal physical property) on the return samples. We will establish the detailed description procedure, including full three-dimensional optical imaging, thermal diffusivity measurement, and non-atmospheric X-ray computed tomography (XCT; Bruker SkyScan 1272) imaging.
References: [1] Kawakatsu, Y. et al. (2023) Acta Astronautica 715–728. [2] Kuramoto, K. et al. (2022) Earth, Planets and Space, 74 (12). [3] Hamilton, V. E. et al. (2019) Nature Astronomy 3, 332–340. [4] DellaGiustina, D. N. et al. (2020) Nature Astronomy 5, 31–38. [5] Miyazaki, A. et al. (2023) Earth, Planets, and Space 75 (171). [6] Hatakeda, K. et al. (2023) Earth, Planets, and Space 75 (46).
Initial description. We will observe the bulk and individual Bennu samples with visible and infrared spectrometers within the N2 clean chamber. Infrared reflectance spectra of the Bennu samples will be obtained using a μFT-IR (wavelength: 2.0–13 μm) and MicrOmega (wavelength: 0.99–3.7 μm). We will confirm whether the band depth of OH-band (2.7–3.0 μm) between Ryugu and Bennu samples is different, as observed by the remote-sensing [3]. Visible and near-infrared band spectra of the samples will also be obtained through a flat glass window using a suite of cameras; a digital microscope with six band filters (ul [388 nm], b [475 nm], v [551 nm], Na [588 nm], w [699 nm], and x [852 nm]) and visible–infrared cameras (OROCHI; center wavelengths: 390, 480, 550, 650, 730, 860, and 950 nm). These two cameras will contribute to finding exogenous grains likely be delivered from other asteroids, potentially included in the Bennu samples [4].
Detailed description. The observation within the N2 clean chamber has several limitations [5–6]. We plan to characterize the return samples outside the clean chambers to verify the accuracy of values obtained within the initial description (e.g., bulk density [5]) and provide further information (e.g., thermal physical property) on the return samples. We will establish the detailed description procedure, including full three-dimensional optical imaging, thermal diffusivity measurement, and non-atmospheric X-ray computed tomography (XCT; Bruker SkyScan 1272) imaging.
References: [1] Kawakatsu, Y. et al. (2023) Acta Astronautica 715–728. [2] Kuramoto, K. et al. (2022) Earth, Planets and Space, 74 (12). [3] Hamilton, V. E. et al. (2019) Nature Astronomy 3, 332–340. [4] DellaGiustina, D. N. et al. (2020) Nature Astronomy 5, 31–38. [5] Miyazaki, A. et al. (2023) Earth, Planets, and Space 75 (171). [6] Hatakeda, K. et al. (2023) Earth, Planets, and Space 75 (46).