Distinguishing between Shock-darkening and Space-weathering Trends in Ordinary Chondrite Reflectance Spectra

0541356 - GLÚ 2022 RIV GB eng J - Článek v odborném periodiku
Kohout, Tomáš - Penttilä, A. - Mann, P. - Cloutis, E. - Čuda, J. - Filip, J. - Malina, O. - Reddy, V. - Grokhovsky, V. I. - Yakovlev, G. A. - Halodová, P. - Haloda, J.
Distinguishing between Shock-darkening and Space-weathering Trends in Ordinary Chondrite Reflectance Spectra.
The Planetary Science Journal. Roč. 1, č. 2 (2020), č. článku 37. E-ISSN 2632-3338
Grant CEP: GA MŠMT LH12079
Institucionální podpora: RVO:67985831
Klíčová slova: Meteorite * chondite * shock * space weathering * reflectace spectrum
Obor OECD: Astronomy (including astrophysics,space science)
Způsob publikování: Open access
https://iopscience.iop.org/article/10.3847/PSJ/aba7c2/pdf

Space-weathering as well as shock effects can darken meteorite and asteroid reflectance spectra. We present a detailed comparative study on shock-darkening and space-weathering using different lithologies of the Chelyabinsk LL5 chondrite. Compared to space-weathering, the shock processes do not cause significant spectral slope changes and are more efficient in attenuating the orthopyroxene 2μm absorption band. This results in a distinct shock vector in the reflectance spectra principal component analysis, moving the shocked silicate-rich Chelyabinsk spectra from the S-complex space into the C/X complex. In contrast to this, the space-weathering vector stays within the S complex, moving from Q type to S type. Moreover, the 2 μm to 1 μm band depth ratio (BDR) as well as the 2 μm to 1 μm band area ratio (BAR) are not appreciably affected by shock-darkening or shock melting. Space-weathering, however, causes significant shifts in both BDR and BAR toward higher values. Application of the BDR method to the three distinct areas on the asteroid Itokawa reveals that Itokawa is rather uniformly space-weathered and not influenced by regolith roughness or relative albedo changes.
Trvalý link: http://hdl.handle.net/11104/0318954