Evidence for asteroid space weathering from the Sloan Digital Sky Survey

Space weathering trends among carbonaceous asteroids

“…This difference implies the spectral slopes of C-complex asteroids become redder over time, which is consistent with the trends observed by Lazzarin et al (2006). Although the slope evolution of C-complex asteroids appears consistent with silicate-rich asteroids (Nesvorný et al 2005;Lazzarin et al 2006), the albedo trends are not. Masiero et al (2011) find the younger Karin family has a lower albedo than the older Koronis family.…”

“…In addition to the difference in phyllosilicate features, the Veritas family albedos show that they are darker than the Beagle asteroids, but comparable to the older Themis asteroids. Thus, these data imply a significant difference in the composition between the Veritas and Themis/Beagle families and that the trend observed by Nesvorný et al (2005) is likely a product of mineralogical variation rather than space weathering processes.…”

“…The intrinsically dark (p v ∼0.06; Mainzer et al 2011) nature of carbonaceous material and the lack of prominent absorption features at visible and near-IR wavelengths implied space weathering trends would be difficult to identify for C-complex asteroids (Hapke 2001;Moroz et al 1996). However, two recent studies indicate significant spectral slope variation among this class of asteroids as a function of age (Nesvorný et al 2005;Lazzarin et al 2006). …”

“…Principal component analyses of asteroid colors in the Sloan Digital Sky Survey (SDSS) show the mean slopes of C-complex asteroid families experience a decrease in slopes and become spectrally bluer with age at visible wavelengths (Nesvorný et al 2005). In contrast, a study using visible spectroscopic data from the Small Main-Belt Asteroid Spectroscopic Survey (SMASSII; Bus & Binzel 2002b), shows the spectral slopes of the C-complex asteroid population as a whole increase (redden) with age (Lazzarin et al 2006).…”

“…The Nesvorný et al (2005) and Lazzarin et al (2006) studies indicate significant evidence of space weathering trends among the C-complex asteroids, however the effects of compositional variation on these trends is still unclear. In the case of S-complex asteroids, Nesvorný et al (2005) use the Koronis asteroid family and Karin cluster, which formed from the breakup of a Koronis family member, to study space weathering trends while avoiding the influence of compositional variation.…”