Synthesis, characterization, and laboratory space weathering of carbonaceous asteroid simulants: a systematic approach to analyzing space weathering effects of carbon-bearing species
Abstract
The spectral differences between C-type asteroids and their presumed daughter carbonaceous chondrite meteorites have often been attributed to mineralogical changes caused by space weathering. However, radiation experiments on carbonaceous chondrites have revealed spectral trends far more complicated than those predicted by studies of lunar space weathering (i.e., spectral reddening, albedo darkening, and band depth decrease attributed to SMFe formation). However, the presence of even small amounts of carbon-bearing species can have pronounced effects on spectra; therefore, chemical changes in carbon-bearing species induced by space weathering of the regolith may be one of the reasons for these unexpected spectral trends. Thus, there is a need for systematic experiments precisely constraining the mineralogy and organic content of carbonaceous asteroids and meteorites to fully understand how space weathering alters these bodies. The CLASS Exolith Laboratory at the University of Central Florida produces high-fidelity simulants of asteroid regolith, allowing for complete control over mineralogy and organic content to enable such a systematic investigation. Carbonaceous asteroid regolith simulants with a variety of organic species are synthesized, compared spectroscopically to a variety of classes of carbonaceous meteorites, weathered via laboratory simulations alongside with their analogous meteorites, and subsequently analyzed using spectroscopy in the visible, near-IR, and mid-IR ranges as well as surface analysis techniques like SEM/EDX. The inclusion of the mid-IR range in particular enables changes in functionality of organic compounds to be monitored. This methodical approach can elucidate whether and how changes in the organic content of low-albedo asteroids and meteorites can affect their spectra, as well as assist in the analysis of remote spectra and returned samples from carbon-rich asteroids like Bennu and Ryugu.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMP014.0005S
- Keywords:
-
- 6008 Composition;
- PLANETARY SCIENCES: COMETS AND SMALL BODIES;
- 6025 Interactions with solar wind plasma and fields;
- PLANETARY SCIENCES: COMETS AND SMALL BODIES;
- 6205 Asteroids;
- PLANETARY SCIENCES: SOLAR SYSTEM OBJECTS;
- 5410 Composition;
- PLANETARY SCIENCES: SOLID SURFACE PLANETS