We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Evidence for the Presence of Thin and Heterogenous Dust Deposits on Ryugu's Boulders From Hayabusa2 MARA and Sample Data.
- Authors
Hamm, M.; Hamilton, V. E.; Goodrich, C. A.
- Abstract
Middle infrared spectral results obtained in‐situ by the Hayabusa2 MARA instrument are generally in‐line with previous results and a new comparison with sample C0137 returned from asteroid (162173) Ryugu, being similar to an aqueously altered CI1 chondrite. The mid‐IR spectrum of the boulder on Ryugu measured by MARA is shallower around 9 μm compared to the laboratory spectrum of C0137. Here we show that discontinuous, fine dust deposits can partially explain the differences in the spectral data and remain in agreement with the temperature observations of the boulder by MARA if an opaque dust layer covers less than 3% of the field of view. Such a presence of dust covering a low porosity boulder was discounted by previous analysis of the mid‐infrared MARA data which did not consider a highly porous boulder as we do here. Plain Language Summary: The Japanese Hayabusa2 space mission returned samples from asteroid Ryugu. Here we compare the spectra of the sample observed in the middle infrared (5–25 μm) with in‐situ observations in the part of the electromagnetic spectrum. We find differences between the spectra that can be explained by the presence of fine particles on the surface of Ryugu. Earlier works found that little to no dust can be present on Ryugu and we revisit these studies an derive an upper limit on the amount of dust consistent with the infrared observations. We find that less than 3% of the observed surface can be covered in an opaque dust layer which is likely concentrated in cracks and pores. Our results are consistent with the results of other studies that the amount of dust that a surface of an asteroid can retain decreases with its size. Key Points: The Ryugu sample C0137's mid‐IR spectrum shows differences to in‐situ observations by MARAThe differences can be explained by the presence of dust on the boulders of RyuguThermal modeling reveals that dust covering less than 3% of the MARA field of view is consistent with the MARA data
- Subjects
DUST; PARTICULATE matter; BOULDERS; ELECTROMAGNETIC spectrum
- Publication
Geophysical Research Letters, 2023, Vol 50, Issue 21, p1
- ISSN
0094-8276
- Publication type
Article
- DOI
10.1029/2023GL104795