Linking Cause and Effect: Nanoscale Vibrational Spectroscopy of Space Weathering from Asteroid Ryugu

Laforet, Sylvain ; Le Guillou, Corentin ; de la Peña, Francisco ; Walls, Michael ; Tizei, Luiz H. G. ; Marinova, Maya ; Beck, Pierre ; Phan, Van T. H. ; Jacob, Damien ; Mouloud, Bahae-eddine ; Hallatt, Daniel ; Pelaez-Fernandez, Mario (Universidad de Zaragoza) ; Viennet, Jean-Christophe ; Troadec, David ; Noguchi, Takaaki ; Matsumoto, Toru ; Miyake, Akira ; Yurimoto, Hisayoshi ; Leroux, Hugues

Resumen: Airless bodies are subjected to space-weathering effects that modify the first few microns of their surface. Therefore, understanding their impact on the optical properties of asteroids is key to the interpretation of their color variability and infrared reflectance observations. The recent Hayabusa2 sample return mission to asteroid Ryugu offers the first opportunity to study these effects, in the case of the most abundant spectral type among the mainasteroid belt, C-type objects. This study employs vibrational electron energy-loss spectroscopy in the transmission electron microscope to achieve the spatial resolution required to measure the distinct mid-infrared spectral signature of Ryuguʼs space-weathered surface. The comparison with the spectrum of the pristine underlying matrix reveals the loss of structural -OH and C-rich components in the space-weathered layers, providing direct
experimental evidence that exposure to the space environment tends to mask the optical signatures of phyllosilicates and carbonaceous matter. Our findings should contribute to rectifying potential underestimations of water and carbon content of C-type asteroids when studied through remote sensing with new-generation telescopes.

Idioma: Inglés

DOI: 10.3847/2041-8213/ad2b65

Año: 2024

Publicado en: ASTROPHYSICAL JOURNAL LETTERS 963, 2 (2024), L45 [11 pp.]
ISSN: 2041-8205

Tipo y forma: Article (Published version)

Área (Departamento): Área Física Materia Condensada (Dpto. Física Materia Condensa.)