Isolating the mechanisms for asteroid surface refreshing
| Autor: | Francesca E. DeMeo, Michaël Marsset, David Polishook, Brian J. Burt, Richard P. Binzel, Sunao Hasegawa, Mikael Granvik, Nicholas A. Moskovitz, Alissa Earle, Schelte J. Bus, Cristina A. Thomas, Andrew S. Rivkin, Stephen M. Slivan |
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| Jazyk: | angličtina |
| Rok vydání: | 2022 |
| Předmět: | |
| Popis: | Evidence is seen for young, fresh surfaces among Near-Earth and Main-Belt asteroids even though space-weathering timescales are shorter than the age of the surfaces. A number of mechanisms have been proposed to refresh asteroid surfaces on short timescales, such as planetary encounters, YORP spinup, thermal degradation, and collisions. Additionally, other factors such as grain size effects have been proposed to explain the existence of these "fresh-looking" spectra. To investigate the role each of these mechanisms may play, we collected a sample of visible and near-infrared spectra of 477 near-Earth and Mars Crosser asteroids with similar sizes and compositions - all with absolute magnitude H > 16 and within the S-complex and having olivine to pyroxene (ol/(ol+opx)) ratios > 0.65. We taxonomically classify these objects in the Q (fresh) and S (weathered) classes. We find four trends in the Q/S ratio: 1) previous work demonstrated the Q/S ratio increases at smaller sizes down to H Accepted for publication in Icarus. 14 pages, 4 figures |
| Databáze: | OpenAIRE |
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