Date of Award


Degree Type


Degree Name

Master of Science




Dr. Paul Wiegert


Space weathering processes are those which act to modify the spectral properties of airless bodies like asteroids. Hiroi et al. [LPSC XXXVI, abstract no. 1396, 2006] recently suggested a new method for estimating the degree of weathering on a body’s surface using an Eight Colour Asteroid Survey (ECAS) type filter system. From May to September 2007, a series of ground-based telescopic observations of Koronis family asteroids in four ECAS colors was carried out to test this method; this study represents the first thorough analysis of Hiroi et al.’s method to date. The results presented here include analysis of the dozen Koronis asteroids observed by the author as well as the data given in Zellner et al. (1985) [Icarus 61, 355-416] for other S-type asteroids in the Main Belt. The spectral properties found are shown, in general, to be consistent with previous studies using other photometric systems. However, while the ECAS inflection method for estimating the degree of space weathering on asteroid surfaces has potential, it was found to be very challenging to obtain reliable results for bodies in space.



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