“What Can We Learn About The Space Weathering Of S-Complex Asteroids In The UV/Blue?”
Reflectance spectroscopy is a major remote sensing probe of a planetary body’s surface mineralogy by Earth-based and spacecraft telescopes. Reflectance spectra of planetary surfaces are generated by the interaction of diffuse sunlight with the top <1 mm of surface material. In the inner Solar System, space weathering affects spectra of Solar System bodies by darkening and reddening their surface materials, as well as degrading absorption features, at visible/near-infrared wavelengths. At ultraviolet/blue wavelengths, a bluing of the spectral reflectance is observed. These effects are well documented for the Moon, where they are apparent in spectra of natural lunar soils, but not seen in spectra of powdered lunar rock samples. The cause of this weathering is likely vapor deposition of submicroscopic iron, through solar wind irradiation, micrometeorite or heavy ion bombardment of the bodies’ surfaces. Space weathering has been proposed as the source of spectral differences between ordinary chondrite meteorites and their proposed parent bodies, S-complex asteroids. We have observed the short-wavelength bluing in S-complex asteroid spectra, and suggest that the UV/blue spectral region is a more sensitive indicator of the onset of space weathering. Thus, the UV/blue reflectance characteristics allow earlier detection of space weathering effects on S-complex asteroids.
The presentation can be seen here.